ROAD SAFETY AUDIT Leverett Circle/Charles Circle City of Boston October 2015 Prepared For: MassDOT Prepared By: McMahon Associates, Inc. 45 Bromfield Street, 6th Floor Boston, MA 02108 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Table of Contents Background ................................................................................................................................. 1 Project Data ................................................................................................................................. 1 Project Location and Description .............................................................................................. 3 Road Safety Audit Observations and Potential Improvements ............................................ 12 Recommendations ..................................................................................................................... 30 List of Appendices Appendix A. Appendix B. Appendix C. RSA Meeting Agenda RSA Audit Team Contact List Detailed Crash Data List of Figures Figure 1: Location Map ............................................................................................................................. 2 Figure 2: Leverett Circle Adjacent Land Uses........................................................................................... 6 Figure 3 Charles Circle Adjacent Land Uses ............................................................................................. 8 List of Tables Table 1. Table 2. Table 3. Participating Audit Team Members ....................................................................................... 3 Estimated Time Frame and Costs Breakdown ..................................................................... 30 Potential Safety Enhancement Summary ............................................................................. 31 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Background The Federal Highway Administration (FHWA) defines a Road Safety Audit (RSA) as the formal safety examination of an existing or future road or intersection by an independent, multidisciplinary team. The purpose of an RSA is to identify potential safety issues and possible opportunities for safety improvements considering all roadway users. This RSA evaluates the following intersections adjacent to Charles Street and Storrow Drive in Boston: Leverett Circle (O’Brien Highway (Route 28)/Charles Street/Nashua Street/Martha Road/I-93 OffRamp) Charles Circle (Charles Street/Cambridge Street/Longfellow Bridge/Storrow Drive Ramps) A review of the Storrow Drive corridor between Leverett Circle and Charles Circle was also conducted as part of the RSA. A safety audit was scheduled for these intersections as part of the required MassDOT design process for the high crash clusters. Leverett Circle is listed as a Highway Safety Improvement Program (HSIP) high crash location from 2010-2012 including 21 crashes involving personal injury with an Equivalent Property Damage Only (EPDO) score of 176. The area around Charles Circle includes multiple HSIP high crash locations identified from 2010-2012. These clusters, ranging from Storrow Drive south of Charles Circle and Cambridge Street east of Charles Circle, to Storrow Drive and Charles Street north of Charles Circle, include 31 crashes involving personal injury and a total EPDO of 356. A key objective of the RSA is to identify both short-term and long-term safety improvements that can be made at the subject intersections. Project Data A Road Safety Audit was completed for the two study area intersections on Thursday, June 18, 2015. The study area is shown in Figure 1. The agenda for the RSA meeting held at the Mass Eye & Ear Infirmary Starr Center is provided in Appendix A of this report. As shown below in Table 1, the audit team consisted of a multidisciplinary team with representatives from state, regional and local agencies providing expertise in the engineering, planning, maintenance and emergency response fields. Contact information for the RSA attendees is provided in Appendix B of this report. Page 1 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Table 1. Participating Audit Team Members Audit Team Member Agency/Affiliation David Otte Massachusetts State Police Joseph Borgomastro Massachusetts State Police Lisa Schletzbaum MassDOT Traffic Safety Tracy Osimboni MassDOT Doug Small MassDOT Amitai Lipton MassDOT District 6 Hameed Pervez MassDOT District 6 Altaf Mulla Division of Capital Asset Management and Maintenance (DCAMM) Wendy Landman WalkBoston Mark Abbott CTPS David Loutzenheiser MAPC Alfredo Vilar Boston Transportation Department (BTD) Caitlyn Duffy Representative Livingstone’s Office Roch Larochelle HDR Alexandria Siu Howard/Stein-Hudson (HSH) James Barnack Jacobs Peter Vasiliou Jacobs Phil Viveiros McMahon Associates Allison Luff McMahon Associates Natalie Raffol McMahon Associates Within the email invitation sent on June 12, 2015 to each participant in the RSA, background material was provided. This information included collision diagrams and crash data summaries for the study area intersections. During the RSA meeting, these materials were reviewed as a group prior to the field visit to the intersections. During the RSA field visit, various safety issues were observed and identified. Following the RSA field visit, the team returned to discuss additional concerns and potential solutions for the existing safety issues. Project Location and Description Study Area Roadways There are several roadways that service the study area intersections that are described below: Charles Street Charles Street (Route 3) is a principal arterial under the Department of Recreation and Conservation (DCR) jurisdiction. Charles Street is a one-way roadway that generally has two travel lanes within the study area that provides a connection between Charles Circle to the south and Leverett Circle to the north. Parking on Charles Street is typically not provided within this segment; however, there are emergency vehicles queued Page 3 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL in front of buildings affiliated with the Massachusetts General Hospital (MGH) and on-street parking is provided approximately 200 feet to the north of Fruit Street. Vehicles are also observed to be parked in areas where parking is restricted along the southern side of Charles Street. A sidewalk is provided along the southern side of the roadway and no bicycle amenities are provided on Charles Street. Storrow Drive/David Mugar Way Storrow Drive/David Mugar Way (Route 28) is a principal arterial under the Department of Recreation and Conservation (DCR) jurisdiction. The connection from I-93 to Storrow Drive through the tunnel beneath Leverett Circle is under MassDOT jurisdiction. As of the writing of this Final RSA Report, Storrow Drive/David Mugar Way is believed to be a limited access arterial that generally runs in the east/west direction along the Charles River through the City of Boston, connecting Leverett Circle to Soldiers Field Road to the west. Between Charles Street in Charles Circle and Arlington Street to the south, the name of the roadway is officially David Mugar Way. Within the project study area, the roadway travels in the north/south direction with a speed limit of 40 mph, parallel to Charles Street. It is believed to be a truck excluded roadway due to the low bridge clearances (10’4”) within the corridor. Storrow Drive/David Mugar Way provides three lanes of travel in either direction. It is unclear if pedestrian and bicycle users are restricted from using Storrow Drive; clarification of how the roadway is regulated regarding access control and pedestrian/bicycle access was not able to be obtained from DCR prior to the completion of this Final RSA Report. There are two pedestrian bridges that span the roadway within the study area. The first is the Charles Street Footbridge immediately south of Longfellow. The other is the Blossom Street Footbridge, which is not in compliance with the Americans with Disabilities Act (ADA). Along this corridor, the roadways will be referred to as Storrow Drive throughout the remainder of this report. Interstate 93 I-93 is an Interstate highway under MassDOT jurisdiction providing the major north/south route through Boston and eastern Massachusetts. Exit 26 on I-93 provides access to Storrow Drive. To and from the southern portion of I-93, Storrow Drive is accessed via ramps that tunnel beneath Leverett Circle. To and from the north on I-93, the ramps exit to the surface roadways and vehicles must navigate through Leverett Circle to access Storrow Drive. From I-93 to and from the south, ramps are also provided to the surface roadways to access Route 28 to the north towards Cambridge. O’Brien Highway O’Brien Highway (Route 28) is a principal arterial under DCR jurisdiction within the city limits of Boston and under MassDOT jurisdiction to the north into Cambridge. O’Brien Highway provides a connection between Cambridge/Somerville and Leverett Circle. Adjacent to the project site, O’Brien Highway provides two lanes of travel in the northbound direction and three lanes of travel in the southbound direction with the rightmost lane providing exclusive access to Storrow Drive via a right turn. A sidewalk is provided on either side of O’Brien Highway, which provides a pedestrian route to the Museum of Science on the southern side of the roadway. There are signs and pavement markings (“sharrows”) for motorists to share the road with cyclists provided in either direction. Page 4 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Nashua Street Nashua Street is an urban principal arterial under City of Boston jurisdiction that connects Leverett Circle to the Suffolk County Courthouse and North Station/Causeway Street to the south. Nashua Street is a twoway roadway that provides one lane of travel in either direction. Sidewalks are provided on both sides of the roadway. There are no bicycle amenities on Nashua Street and there is no available on-street parking in the vicinity of the study area. Martha Road Martha Road is an urban minor arterial under the City of Boston jurisdiction that provides a connection between Leverett Circle and North Station/Causeway Street. Martha Road is a one-way roadway exiting Leverett Circle and travelling south that provides two lanes of travel. Martha Road has a sidewalk provided on the southern side of the roadway and sharrows provided within travel lanes. Cambridge Street Cambridge Street is an urban principal arterial under City of Boston jurisdiction that runs in the east/west direction through Boston, connecting Tremont Street to the east and Charles Circle/Longfellow Bridge roadway to the west. Cambridge Street is a two way roadway that provides two travel lanes in either direction. Cambridge Street is typically median divided and provides a sidewalk on either side of the roadway, providing additional refuge for crossing pedestrians. Metered on-street parking is provided along Cambridge Street on either side of the roadway. There are no amenities available on Cambridge Street dedicated to bicyclists. Longfellow Bridge Longfellow Bridge is a principle arterial under MassDOT jurisdiction. It runs into Charles Circle from the west, connecting Cambridge and Boston. Currently, Longfellow Bridge is undergoing reconstruction and vehicular traffic is allowed only in the Boston-bound direction; Charles Street, from Charles Circle to Leverett Circle, is temporarily carrying all Cambridge-bound Longfellow Bridge vehicular traffic. Typically, vehicles would enter and exit Charles Circle onto the bridge in one of two travel lanes in each direction. There are also bike lanes in each direction during construction. Travel lanes are separated by the MBTA Red Line tracks. Study Area Intersections Leverett Circle As shown in Figure 2, there are several roadways that feed into Leverett Circle, including Charles Street from the south, O’Brien Highway from the west, Nashua Street to the north, and the I-93 off-ramps to the east. Traffic signals at Leverett Circle are owned by DCR, but operated by the Boston Transportation Department (BTD). In the center of Leverett Circle, there is Science Park Station, a Massachusetts Bay Transportation Authority (MBTA) station that accesses the rapid transit Green Line. Page 5 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Leverett Circle can be broken down into three clustered intersections. On the western side of Leverett Circle, O’Brien Highway enters from the west, Nashua Street enters from the north, the northbound left turn from Charles Street enters from the south, and traffic from the eastern section of Leverett Circle enters from the east. To the south, there is a one-way southbound ramp to Storrow Drive. O’Brien Highway provides an exclusive right turn lane for traffic accessing Storrow Drive and two exclusive through lanes continuing through Leverett Circle. Nashua Street provides an exclusive channelized right turn lane to O’Brien Highway and two exclusive through lanes to Storrow Drive. The eastbound approach from Leverett Circle provides two exclusive through lanes to O’Brien Highway for traffic from the I-93 ramps, and Charles Street provides two exclusive northbound left turn lanes to O’Brien Highway. On the eastern portion of Leverett Circle, Charles Street enters from the south and provides access to the I93 ramps as well as Martha Road to the west via three unmarked lanes. The I-93 southbound off-ramp enters from the east and provides two lanes that continue through to O’Brien Highway. Nashua Street enters from the north and provides two lanes marked as shared through/right turn lanes that access the I-93 southbound on-ramp or Martha Road. The traffic from O’Brien Highway continues through Leverett Circle to this intersection from the west and accesses the I-93 ramps and Martha Road to the east. On the northern portion of Leverett Circle, Nashua Street enters from the north and splits to allow traffic to enter to the eastern and western sections of Leverett Circle, providing one lane to the west and one lane to the east. The I-93 southbound off-ramp enters the intersection from the south, providing two through lanes that continue to Nashua Street. The I-93 northbound off-ramp enters the intersection from the east and provides an exclusive channelized right turn lane and two exclusive through lanes that continue through to Nashua Street southbound towards O’Brien Highway and Storrow Drive. Beneath Leverett Circle, there are additional connections between I-93 and Storrow Drive in both directions. Charles Circle Figure 3 illustrates the roadways that make up Charles Circle. Cambridge Street leads into Charles Circle from the east, Longfellow Bridge from the west, and both Charles Street and Storrow Drive run north/south through the circle. These two roads approach the intersection at different angles, resulting in the lack of a continuous north to south connection through the intersection. In the center of Charles Circle, there is the MBTA Charles/MGH Station that accesses the rapid transit Red Line and contributes to a lack of a clear delineated path east to west. Traffic signals at Charles Circle are owned by DCR, but operated by BTD; these signals are currently operating in coordination with the ongoing Longfellow Bridge construction project. Charles Circle can be viewed as three separate intersections. The first is to the north east of the MBTA station where Cambridge Street approaches from the east. Cambridge Street contains three travel lanes: one through lane to the far left, a through/right turn lane in the middle, and a right turn only lane on the far right. The right turn only lane provides access to Charles Street northbound, which is a three-lane, one way street. The through/right turn middle lane provides access to Storrow Drive westbound, which is a two-lane, oneway roadway, as well as a small paid parking lot between Storrow Drive and Charles Street. Due to the construction on Longfellow Bridge, vehicles continuing straight in one of the through Page 7 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL lanes are directed to turn left in one of two left-turn only lanes west of this intersection, under Longfellow Bridge to continue around Charles Circle. These left turn lanes merge in the next intersection with vehicles approaching the intersection from the north on an off-ramp from Storrow Drive westbound. Two travel lanes approaching from Storrow Drive westbound provide traffic through the circle, under Longfellow Bridge. Due to construction on Longfellow Bridge, two eastbound right turn lanes enter this intersection from what would normally be the westbound departure lanes toward Cambridge; in addition, the channelized right-turn lane from the Storrow Drive westbound off-ramp that provide access to Longfellow Bridge westbound is closed. An exit driveway for the small paid parking lot between Storrow Drive and Charles Street also approaches the intersection from the north.The southern portion of Charles Circle contains the most traffic movement. Vehicles from the Storrow Drive westbound off-ramp enter the intersection in one of two southbound lanes under the Longfellow Bridge. Though now closed for construction, three eastbound lanes from the Longfellow Bridge also approach the intersection vehicles approaching from two lanes on the Storrow Drive eastbound offramp enter the intersection parallel with the (closed) Longfellow Bridge eastbound approach. Vehicles approaching from either the Longfellow Bridge or the Storrow Drive eastbound off-ramp may either continue straight onto Cambridge Street or take left turns onto either the Storrow Drive westbound on-ramp or Charles Street northbound; both turns go under the Longfellow Bridge with three travel lanes each separated by a median. Traffic entering Cambridge Street eastbound from either the Longfellow Bridge or the Storrow Drive westbound off-ramp is separated by a median from traffic entering Cambridge Street eastbound from the Storrow Drive eastbound off-ramp. All of these lanes merge east of the median as Cambridge Street forms into a two-lane road to the east of Charles Circle. Crash Data Leverett Circle Crash data was reviewed by Howard/Stein-Hudson Associates, Inc. (HSH) as part of the Leverett Circle Pedestrian Bridge project. Crash data was obtained from MassDOT for the most recent three year period available (2010-2012). Based on the crash data and collisions diagrams provided by HSH, there were a total of 61 crashes that occurred in Leverett Circle over the three year period. Of these crashes, 29 occurred at the intersection of O’Brien Highway/Nashua Street/Storrow Drive, 26 occurred at the intersection of Nashua Street/Charles Street/Martha Road, and six occurred at the intersection of Nashua Street and the I93 Ramps. At the intersection of O’Brien Highway/Nashua Street/Storrow Drive, ten of the crashes that occurred are sideswipe collisions, and seven crashes that occurred were angle collisions between conflicting movements of traffic. The majority of the crashes that occurred resulted in property damage only and occurred under dry and well lit conditions. There is no clear trend that pertains to the time of day or day of the week the crashes occurred. One crash that occurred at this intersection involved a bicycle as a vehicle attempted to change lanes improperly. Another crash involved a vehicle that made a right turn on red while this movement was restricted and struck a pedestrian in the Storrow Drive crosswalk. Page 9 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL At the intersection of Nashua Street/Charles Street/Martha Road, 12 crashes that occurred were rear-end collisions, which is typical for a signalized intersection. The remaining crashes at this location varied in crash type. The majority of crashes at this location occurred during dry, clear conditions during the daytime. There was one crash that involved a pedestrian crossing adjacent to the ramps to I-93. Per the crash report, the pedestrian moved into the roadway unexpectedly and was struck by a vehicle. At the intersection of Nashua Street/I-93 ramps, six crashes occurred over the three year period analyzed, the majority of which were rear-end collisions. The majority of crashes at this location occurred during dry, clear conditions during the daytime. Charles Circle Crash data was obtained from MassDOT and reviewed by Jacobs Engineering for the most recent three year period available (2010-2012). The crash diagrams provided by Jacobs show a total of 32 crashes in Charles Circle over this time period. Of these crashes, nine occurred at the intersection of the Storrow Drive westbound off-ramp, Cambridge Street westbound, and Longfellow Bridge; 11 occurred at the intersection of the Storrow Drive westbound on-ramp, Charles Street northbound, and Cambridge Street; and 12 occurred at the intersection of the Storrow Drive eastbound off-ramp, Longfellow Bridge eastbound, Charles Street southbound, and Cambridge Street. At the intersection of the Storrow Drive westbound off-ramp, Cambridge Street, and Longfellow Bridge westbound, two of the crashes that occurred were rear ends of vehicles coming from the Storrow Drive westbound off-ramp. Two cars were involved in a crash while entering the right hand lane to continue toward the Longfellow Bridge, while four cars were involved in a rear end collision while continuing onto the Storrow Drive westbound off-ramp in a left lane. Both of these crashes resulted in non-fatal injuries. Seven of the nine crashes were angle collisions between vehicles on the Storrow Drive westbound off-ramp and Cambridge Street. All of these crashes resulted in property damage only. At the intersection of the Storrow Drive westbound on-ramp, Charles Street northbound, and Cambridge Street, four of the 11 crashes that occurred were sideswipes. Three of the crashes were angle collisions between Charles Street northbound and Cambridge Street. There was one rear end collision at this location as well. Three were collisions with objects, presumably the median on Cambridge Street, with two of those resulting in non-fatal injuries. At the intersection of the Storrow Drive eastbound off-ramp, Longfellow Bridge eastbound, Charles Street southbound, and Cambridge Street, three of the crashes that occurred were rear ends with vehicles traveling eastbound off of the Longfellow Bridge. Two crashes on the Longfellow Bridge eastbound were collisions with the left-hand side of the bridge, with one resulting in a non-fatal injury. There was one angle collision between a vehicle coming from the Longfellow Bridge eastbound and a vehicle entering Charles Street northbound within the circle. Of the crashes occurring from the Storrow Drive westbound off-ramp approach, two were sideswipes, one rear end collision, and one angle collision. Two of these involved nonfatal injuries. There was one sideswipe crash and one rear end crash between vehicles approaching the Storrow Drive westbound on-ramp from within the intersection. Page 10 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL While not included in the crash diagrams, it was noted during the RSA that a pedestrian fatality occurred at the pedestrian crosswalk in front of the Cambridge Street westbound approach (adjacent to the Charles/MGH station) in March 2015. Based on discussion during the RSA, the crash involved a pedestrian who entered the crosswalk against a “Don’t Walk” signal just as the Cambridge Street westbound approach received its green phase, and was struck by a truck who did not see the pedestrian as the green phase began. Detailed crash diagrams are provided in Appendix C. Page 11 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Road Safety Audit Observations and Potential Improvements During the RSA meeting prior to the field visit, a brief introduction of the RSA process and a summary of crash information was presented to the audit participants. Following this brief presentation, the members of the audit team were asked to discuss the existing issues that may affect safety at the two study area intersections and the segment of Storrow Drive between them. The audit team then visited the site as a group, at which time observations of various safety concerns and deficiencies were identified and documented. Provided below is a list of the safety concerns that were identified during the RSA for each intersection and for the corridor as a whole and the potential enhancements identified during the RSA. Leverett Circle Safety Issue #1: Pedestrian Crossing and Wayfinding Observations: Pedestrian safety within Leverett Circle was a major discussion point by the RSA team due to the high volume of pedestrians traveling to the Science Park train station that lies in the middle of the circle and the adjacent Museum of Science. Along the southern portion of the intersection, in order to travel east/west through the corridor, pedestrians must cross three separate crossings: one spanning Storrow Drive, one spanning the Charles Street left turn lanes, and one spanning the remaining Charles Street lanes. A pedestrian does not have the walk time to cross all three crossings at once, and therefore must wait several light cycles to fully cross east/west. It was observed that pedestrians are often not willing to wait this time to cross and cross on a “don’t walk” phase when there is a gap in traffic. There are also times where a walk phase would be able to be implemented, but there is a “don’t walk” phase with no vehicular conflicts. Pedestrians cross when they see there are no conflicting vehicles for that phase, but are not protected with a walk phase. Many pedestrians were observed walking from Science Park Station towards Boston to the east. There is a pedestrian desire line from the northeast corner of O’Brien Highway/Nashua Street/Storrow Drive to the southwest. Pedestrians who are familiar with the area aren’t using the crossing that is available spanning the westbound approach from Leverett Circle to O’Brien Pedestrian crossing from Science Park Station towards Highway and then the crossing the Charles Street median spanning the Charles Street left turn lanes; aside from making two separate crossings, pedestrians crossing the westbound approach during the “Walk” phase occasionally encounter vehicles turning left from Nashua Street Page 12 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL southbound that yield to pedestrians in the crosswalk before completing this turn. Pedestrians are instead crossing when there is a gap in traffic or when the crossing is protected directly to the island splitting the Charles Street approaches; this crossing is protected when the Charles Street left turn is running, through there is no crossing striped for this movement. Vehicle speeds through the corridor were observed to be high, presenting potential hazards with the large volumes of pedestrians in this area. The majority of the vehicles through this circle are either going to or coming from I-93. For the right turn from O’Brien Highway onto Storrow Drive, there is a “No Right Turn on Red” sign that is illuminated when the crosswalk spanning Storrow Drive has a walk phase. This occurs concurrently with the northbound left turn phase from Charles Street. Once this phase ends, the illuminated “No Right Turn on Red” sign turns off, allowing right turns on red. The sign is not illuminated when the walk phase is Illuminated “No Right Turn on Red” signage for the right turn from O’Brien Highway onto Storrow Drive active for the western crosswalk spanning O’Brien Highway, allowing potential conflicts between the right on red movement and pedestrians. It was also observed that many vehicles do not observe the “No Right Turn on Red” signage and made right turns through the crosswalk onto Storrow Drive during the walk phase. There is also the potential for pedestrian/vehicle conflict when drivers arrive at the intersection when the sign is not lit. A driver may be looking left for gaps in vehicular traffic, but then may make a right turn when not having seen the sign illuminated. There is signage in the southbound direction from Nashua Street to yield to pedestrians in the crosswalk for the southbound left turn. The sign is far to the left and in a position that is difficult for drivers to see, as it is just beyond the bridge abutment. Additionally, there are large volumes of pedestrians that travel to the Museum of Science via the Science Park MBTA Station, but it was observed that there is no wayfinding for pedestrians from the train station to the Museum of Science. The State Police reported encountering many lost pedestrians looking for the Museum of Science, illustrating confusion in the area. Enhancements: Evaluate pedestrian crossing phasing and timings on the southern side of Leverett Circle to ensure pedestrians are able to cross during all available phases for the maximum possible time to facilitate pedestrian operations. This evaluation should consider existing Page 13 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL preemption of signals when the Craigie Drawbridge opens, as well as the capability of the existing signal to accommodate additional phases or pedestrian movements. Considering providing a crossing between the northeastern side of the O’Brien Highway/Nashua Street/Storrow Drive intersection and the island between the Charles Street approaches and allow a protected crossing phase when the Charles Street northbound left turn is active to protect this desired pedestrian route. Consider introducing traffic calming measures such as bold signage, extra visible crosswalks, and overhead signs adjacent to signal heads, approaching the intersection to reduce vehicle speeds and remind drivers that they are in a high pedestrian activity area despite its proximity to the highway. Evaluate impacts of restricting eastbound right turn to Storrow Drive to ‘No Right Turn on Red” permanently to reduce confusion of when drivers are allowed to turn right. Consider replacing illuminated “No Right Turn on Red” sign with red arrows and supplemental right turn restriction signage to portray a clearer message regarding the right turns on red, if impacts are deemed acceptable. Consider restricting right turns on red when the western crosswalk spanning O’Brien Highway has a protected crossing to reduce conflicts between right turns and pedestrians. Consider providing wayfinding signage from Science Park Station to the Museum of Science to help pedestrians cross at appropriate and safe crossings. Consider restricting the southbound left turn from Nashua Street at O’Brien Highway and require all left turns to access Leverett Circle via the Nashua Street connection opposite Charles Street to reduce conflicts with the crosswalk connecting to Science Park Station. Evaluate moving pedestrian warning signage to a more optimal location to increase visibility. Evaluate placing a flashing yellow arrow (FYA) indication for vehicles turning right onto Storrow Drive westbound from Route 28/O’Brien Highway, to indicate to drivers that while a right turn is permitted, they must yield right-of-way to the concurrent pedestrian movement. Evaluate options for standard signage at Leverett Circle and consider removing all nonstandard signage, including warning signs related to pedestrian movements. Consider the proposed Pedestrian Overpass Bridge at Leverett Circle (MassDOT Project 606703) to improve pedestrian circulation. Page 14 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Safety Issue #2: Bicycle Operations Observations: It was observed that there are no bicycle amenities within Leverett Circle and that bicycles must use the roadway as a means to navigate through the circle. This proves challenging to cyclists due to the observed speed differentials between vehicles and bicycles through this corridor, as well as frequent lane changes. Several bicyclists opt to use the adjacent sidewalks to seek refuge Bicyclist seeking refuge from vehicular traffic on the through the circle, creating additional sidewalk conflicts with the large volumes of pedestrians in this area. Poor biking infrastructure also affects the State Police, who could benefit from easier access going to and from their barracks on O’Brien Highway by bike. Enhancements: Consider providing exclusive bicycle lanes to allow cyclists a protected lane of travel. Consider providing bike boxes at the traffic signals to allow cyclists a protected queuing area ahead of queued vehicles to increase cyclist visibility. Consider providing safe bicycle connections through the intersection, which may include on-road bike lanes, a cycle track, or a shared use path. Safety Issue #3: Lane Usage Observations: The northbound movement from Charles Street was observed to be an issue during the RSA field visit. Three lanes are provided on Charles Street for the movements to I-93 northbound, I-93 southbound, and Martha Road towards North Station, east of Leverett Circle. Advance overhead guide signage is provided to the south on Driver of the white van photographed attempts to Charles Street showing these access Martha Road on the right, from the left lane on destinations, but no specific lane Charles Street utilization signage or striping is provided at the intersection. Therefore, vehicles use any lane to access their destination; east of the intersection, overhead guide signage identifies each destination directly above the decision points. Page 15 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL During the field visit, all three lanes were observed attempting to access the I-93 southbound ramp, causing conflicts with vehicles traveling to the I-93 northbound ramp from the center lane. Additionally, some vehicles destined for Martha Road were observed to access the intersection from the left-most lane and cut across the adjacent two lanes to access Martha Road. A similar movement was observed by a vehicle from the right-most lane accessing I-93 northbound. Driver confusion may be a contributing factor to these last minute lane changes, and these movements are likely a contributing factor to the number of sideswipe and angle collisions at this intersection. Another safety issue is that trees along Charles Street block the advanced warning sign for Martha Road from view. At the intersection of O’Brien Highway/Nashua Street/Storrow Drive, there is an issue in the eastbound direction of vehicles continuing through into Leverett Circle from the right-most lane that is intended to be a right turn only lane to Storrow Drive. The issue is generally due to congestion in the two through lanes, with vehicles attempting to bypass by continuing through from the Vehicle continuing through from westbound right turn right turn lane. Some vehicles also lane in conflict with through traffic from the center enter the right turn lane from the lane Museum of Science and cannot move into the through lanes to access I-93 due to queueing. Additionally, vehicles have been observed to turn right onto Storrow Drive from the center lane that is intended to continue through to I93/Martha Road. These movements may be contributing factors to the number of sideswipe collisions as vehicles attempt to make lane changes to be in the appropriate lanes, and a contributing factor to the number of rear-ends in the eastbound direction as vehicles stop short to make last minute lane changes. Enhancements: Consider providing revised guide signs, which may incorporate diagrammatic lane usage, in advance of Leverett Circle indicating which lanes are to be used to access the various destination points from Leverett Circle to reduce driver confusion and conflicts. Consider providing route guidance pavement markings indicating the destination and appropriate usage for each lane in advance of Leverett Circle to reduce driver confusion and conflicts. Consider providing dotted lane extension lines at intersection locations to provide additional guidance to the appropriate destination lanes. Evaluate channelization of the O’Brien Highway eastbound right turn lane to Storrow Drive by means of plastic delineators to provide a physical barrier keeping vehicles from continuing through to Leverett Circle. Page 16 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Safety Issue #4: Advance Warning Signage Observations: It was noted during the road safety audit that there is “Cars Only” warning signage provided over the Storrow drive on-ramp from Leverett Circle to restrict truck traffic from entering due to the low bridge clearances along Storrow Drive. The “Cars Only” signage is also provided over the westbound right turn lane from O’Brien Highway to Storrow Drive. It was observed during the field and discussed by the RSA team that vehicles accessing Storrow Drive from I-93 northbound do not have signage in advance of the Storrow Drive ramp. Additionally, in several cases, truck traffic will queue on Truck turning last minute onto O’Brien Highway upon Nashua Street in the southbound realizing the Storrow Drive truck restriction direction to enter Storrow Drive, see the warning signage at the last minute, and then attempt to turn right onto O’Brien Highway from the southbound through lane. The signage is also partially obstructed by the Green Line overpass as vehicles approach from Nashua Street. It was noted during the RSA that if trucks do enter Storrow Drive, they are able to continue to the next available exit on the left for Government Center (referred to as a “bail out exit” by one RSA participant) before encountering any of the low bridges. Signage is provided on Storrow Drive to make an emergency exit to the left if heavy vehicles that do not meet height requirements travel onto Storrow Drive. Enhancements: Consider providing signage in advance of the Storrow Drive on-ramp to indicate that trucks are restricted. Consider providing wayfinding signage for an alternate truck route to guide heavy vehicles away from Storrow Drive. Consider providing graphic “No Trucks” signage at entrances to Storrow Drive to supplement existing signage and provide a clear message. Consider providing active warning signs concurrently with a “Laser Detection” system on the Storrow Drive ramps that illuminates when a heavy vehicle enters Storrow Drive to direct vehicles to exit toward Government Center. Page 17 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Safety Issue #5: Construction Impacts Observations: It was noted by an audit team member that there is queueing from the west in Cambridge along O’Brien Highway that extends into Leverett Circle during the weekday morning peak period. This congestion is largely due to construction projects, namely the Charles River Dam project construction, Lomasney construction, and construction from the Northpoint development project to the west of Leverett Circle. Signal coordination is also poor and traffic from the I-93 southbound off-ramp blocks the intersection with Nashua Street. This is a problem throughout the day, not just in the morning peak period. Enhancements: Encourage coordination between DCR, MassDOT, and the City of Cambridge to reduce delay caused by downstream construction projects during peak travel times. Review signal coordination and adjust signal timings accordingly. Safety Issue #6: Roadway Geometry Observations: It was noted during the RSA that the eastbound approach from O’Brien Highway to Leverett Circle is offset slightly, requiring vehicles to move to the right as they continue through to stay in the appropriate lane. This may be a contributing factor to sideswipe crashes at this location. General observations in terms of the Leverett Circle roadway geometry were also made by the project team. Offset eastbound approach to Leverett Circle Overall, the intersection has a very unique layout and may be difficult for unfamiliar visitors to navigate, particularly those visiting the Museum of Science. Enhancements: Evaluate realigning the westbound approach towards O’Brien Highway by narrowing from two lanes to one lane to allow the shifting of the raised median to the north/east, and thus realigning the eastbound approach through the intersection. Evaluate realigning the eastbound approach from O’Brien Highway through Leverett Circle to eliminate the offset. Consider providing dotted lane extension lines from O’Brien Highway to Leverett Circle to provide additional guidance for vehicles passing through the intersection. Page 18 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Consider providing additional wayfinding signage for vehicles to access points of interest around Leverett Circle. Storrow Drive Safety Issue #1: Roadway Geometry Observations: The geometry of Storrow Drive westbound between Leverett and Charles Circles creates numerous safety concerns. There were 36 crashes on Storrow Drive westbound, with the majority of crashes occurring in the weave section between the I-93 Portal and the left exit to Charles Circle. There are also clusters of crashes on the reverse curves before, after and under Longfellow Bridge, as well as at the parking lot driveways at the westbound on and off ramps. Some participants raised concerns about what they characterized as a “double weave” pattern that is created when vehicles are forced to make decisions quickly with changing lane configurations. One main cause of this weaving pattern may be the left-side exit ramp on Storrow Drive westbound. As vehicles enter Storrow Drive westbound from Leverett Circle, vehicles from O’Brien Highway enter Storrow Drive in an added lane adjacent to two lanes of traffic coming from I-93. Vehicles have 600 feet of roadway before having to make a decision regarding the lane in which to travel. This causes vehicles to simultaneously switch lanes in either direction to either stay on Storrow Drive westbound, or exit left towards Government Center; the ability to use the center lane to either exit left toward Government Center or continue on Storrow Drive westbound may create higher demand for this lane and further complicates this issue. Participants agreed that the left side exit ramp may confuse drivers because they expect exits to be on the right side of the road. Of the 36 crashes in this location, 20 were rear end collisions. A similar safety concern exists on Storrow Drive eastbound where two lanes of traffic combine with one added lane of traffic from Charles Street eastbound prior to the development of a double left turn onto O’Brien Highway. Vehicles must also merge and change lanes at this location to get onto I-93 from Storrow Drive eastbound, and also travel through Leverett Circle to access O’Brien Highway. Crashes are primarily clustered in the reverse curves before, after, and under the Longfellow Bridge. Crashes are also clustered near the Blossom Street Bridge where there is a merge of parking lot traffic onto Storrow Drive eastbound. Signage on Storrow Drive may also create confusion for drivers, as the arrows, exit tabs, and “left lane” designations do not appear to conform to current standards. Audit participants have also noted the lack of bicycle or pedestrian exclusion signage at Storrow Drive approaches. Discussions during and after the audit meeting with MassDOT and DCR have not clarified whether the roadway has bicycle or pedestrian exclusions1. Clarification from DCR was not able to be obtained concerning existing bicycle and pedestrian exclusions prior to the completion of this Final RSA Report. 1 Page 19 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Enhancements: Evaluate overall signage and sign placement and positions, with care to avoid sign clutter. Evaluate lane configurations along Storrow Drive, including gore points where travel lanes are added or removed from Storrow Drive. Evaluate switching to right side exits and entrances on Storrow Drive to better conform to driver expectation and to facilitate improved weaving conditions. Evaluate creating a Storrow Drive eastbound direct on-ramp from Charles Circle to the I93 access tunnel. Evaluate grade separations on Storrow Drive to reduce the need for weaving movements. Evaluate the relocation or removal of parking lot ingress/egress points on Storrow Drive ramps. Evaluate softening the sharp reverse curves for both eastbound and westbound Storrow Drive by enlarging the radii. Include bicycle prohibition signage at Storrow Drive entrances as a short-term measure until clarification of bicycle and pedestrian access along the Storrow Drive corridor is provided by DCR. Safety Issue #2: Storrow Drive Single Vehicle Crashes Observations: From the crash data, participants observed a high percentage of wet weather crashes (60%). Participants suggested that the reasons behind a large number of crashes in wet weather could be the pavement type, age, or condition, the presence of narrow lanes, tight curb radii, short curves, and lack of sight distance. Participants noted that it was unclear from the crash data whether these crashes occurred at peak or off-peak times, noting that at off-peak times when Storrow Drive is not congested, vehicles may be traveling as fast as 45 mph, suggesting that speed may be a safety issue as well. Enhancements: Evaluate realigning Storrow Drive with fewer curves and remove/soften sharp radii to allow vehicles to travel through the corridor more safely and with greater visibility. Evaluate use of a high-friction pavement surface to improve vehicle control in inclement conditions. Evaluate drainage system to determine if improvements are needed to reduce puddling or other wet roadway conditions. Evaluate the feasibility of creating boat sections on Storrow Drive to increase vertical clearance over bridge structures. Evaluate the relocation or removal of parking lot ingress/egress points on Storrow Drive ramps. Evaluate pavement marking type/condition along Storrow Drive. Page 20 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Safety Issue #3: Storrow Drive Sideswipe Collisions Observations: Of the 39 crashes on Storrow Drive eastbound, just under a third of them were sideswipe crashes. Participants noted this may be due to the geometric issues discussed previously, such as left-side exit ramps, narrow lanes, and tight radii. Other potential safety issues could be the lack of wayfinding and guidance as vehicles approach Leverett Circle from Storrow Drive eastbound as well as the Mass. Eye and Ear Infirmary surface parking lot that exits directly onto Storrow Drive. As vehicles are traveling at high speeds on Storrow Drive, it may be difficult for those exiting the parking lot to safely enter Storrow Drive without disrupting traffic flow. Enhancements: Consider guide sign improvements to provide improved wayfinding. Remove/re-evaluate direct access to Storrow Drive from surface Vehicles traveling on Charles Street eastbound parking lots. where it merges with Storrow Drive Evaluate use of a high-friction pavement surface to improve vehicle control in inclement conditions. Consider pavement marking type/condition, possibly revising pavement marking lane lines to move traffic away from sight distance obstructions on the inside of horizontal curbs, by “creating” wider shoulders. Evaluate drainage system to determine if improvements are needed to reduce puddling or other wet roadway conditions. Page 21 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Safety Issue #4: Vehicle Clearance Observations: Storrow Drive has a low vertical clearance, which is problematic if trucks enter from Leverett Circle. Although there are warnings in advance of the low clearance conditions, there still may be confusion as to when the height restriction begins on Storrow Drive. Participants also displayed concern over the fact that Storrow Drive is a numbered route, which typically encourages truck traffic. Low clearance warning on Storrow Drive westbound going south from Leverett Circle Enhancements: Evaluate improved warning signage for trucks about the low vertical clearance, possibly using more graphics. Evaluate the removal of numbered route designations along Storrow Drive. Evaluate the potential to increase roadway clearances along Storrow Drive, which could include raising the height of overhead structures or depressing Storrow Drive. Page 22 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Safety Issue #5: Pedestrian Safety Observations: Participants discussed a recent fatal crash that occurred in this area not included in the crash data, which sparked a discussion of pedestrian safety. Participants found the crosswalk in the middle of Charles Street northbound (near Fruit Street) to be difficult for pedestrians. This crosswalk connects Fruit Street with the Mass. Eye and Ear Infirmary parking lot located between Charles Street and Storrow Drive. Faded crosswalk and road curvature as vehicles Participants showed concern that the approach the crossing crosswalk is not visible to vehicles as there is a curve in the road before the crossing and a lack of advance warning for drivers. RSA participants also noted that shade and foliage from trees and cars parked illegally on the street also contribute to a lack of visibility of the crosswalk and signs in the area. Enhancements: Evaluate the placement of a rapid rectangular flashing beacon (RRFB) at the crossing. Evaluate the placement of a raised crosswalk and/or curb extension. Consider improving visibility through road realignment and street tree placement. Enforce existing on-street parking restrictions, which may affect driver visibility of the crosswalk. Evaluate relocating the crosswalk to improve sight distance around the adjacent horizontal curve, while maintaining the pedestrian desire lines. Evaluate the feasibility of adding another pedestrian connection over Storrow Drive, north of Longfellow Bridge and/or improving the Blossom Street footbridge to ADA compliance. Charles Circle Safety Issue #1: Bicycle Conflicts Observations: As Cambridge Street approaches Charles Circle it divides into three lanes: a right turn only lane, a middle lane for either through traffic or right turns, and a left lane for through traffic. A sign on Charles Street before the intersection only depicts two approach lanes and informs drivers that the right lane is to continue onto Charles Street (Route 3) for access to Route 93 South, and the other lane is for right turns onto Storrow Drive westbound. Bike traffic travels on the right side of vehicle lanes to continue straight through the intersection. With double right turning lanes, cyclists are cut off by right-turning vehicles, especially if those in the center-right lane decide to take a sharp right onto Charles Street. Participants agreed that there is unclear guidance for vehicles wishing to turn Page 23 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL right in the intersection onto either Charles Street or Storrow Drive westbound. There were 11 crashes at this location from 2010-2012 with four resulting in injury. Of the five crashes occurring in the two right-most lanes on Cambridge Street, three were sideswipes, illustrating confusion over the intended use of the right lanes. During the field observation, non-standard signage was found supposedly instructing vehicles intending to turn right to yield to cyclists continuing straight onto the Longfellow Bridge, where bike lanes are in place for Cambridgebound traffic. One sign is placed in a median between Charles Street and Storrow Drive, and another placed before the intersection on Cambridge Street. The signs are prohibited under federal and state law, as they use unapproved symbol elements. The signs are also mounted too low, and may pose a safety hazard to pedestrians. One participant noted a lack of signs (such as a “bikes watch for turning vehicles” sign or other regulatory signs) that clarified current traffic conditions. However, there was also concern over “sign-overload” for vehicles entering from Cambridge Street, which diminishes the likelihood for drivers to be adequately informed of potential conditions at the intersection. Signage on Cambridge Street before the intersection Lack of sign visibility as vehicles approach the intersection from Cambridge St. Enhancements: Clarify signs and markings within and in Right turn yield to bikes signage and bike lane onto Longfellow Bridge northbound advance of Charles Circle, preferably with standard, approved signage installed in the correct manner. Evaluate the addition of a bike box in front of all three lanes or bike lanes/shared lanes on Cambridge Street and through the intersection to improve bicycle accommodations. Investigate “innovative” geometric improvements to clarify movements through the intersection. Page 24 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Safety Issue #2: Pedestrian Operations/Charles/MGH Station Access Observations: Some RSA participants stated that they had observed approximately 1,000 pedestrians per hour using the emergency exit doors at the Charles/MGH MBTA station to exit onto the northern side of Cambridge Street. Field observation confirmed that crossing Cambridge Street at the location where these doors exit is popular among pedestrians, creating a clear desired path from the station over to Massachusetts General Hospital (MGH). Participants noted that MGH is a major destination for pedestrians, making it a logical place for a crossing. With MGH as a central destination, pedestrians are likely to continue to cross at this location, rather than walking in the opposite direction to cross at the crosswalk, as studies show pedestrians are unlikely to travel out of the way to reach a destination. Field observation confirmed the use of the emergency exit doors and the crossing over Cambridge Street without a marked crosswalk, in a space that also lacks adequate room for pedestrians waiting to cross. Pedestrians seen crossing Cambridge Street closest to the emergency exit doors Two-phase crossing separated by median on Cambridge Street RSA participants noted the possible reasons as to why there is high usage of the emergency exit doors. Some stated that it was due to a lack of wayfinding as T-riders come down the escalators and try to exit the station. The emergency exit doors are straight ahead, while the regular exit doors require turning around and heading in the opposite direction out of the station. Others stated heavy usage was due to Pedestrian signal push-button on left side of the desire lines of regular users who exit via the crosswalk from Charles/MGH station emergency exit doors to access their destinations in the MGH/downtown Boston direction. For pedestrians exiting the Charles/MGH Station and wishing to cross onto the southern end of Cambridge Street there is a two-phase crossing separated by a median. This poses a safety issue for pedestrians, as they are often impatient and wish to reach a destination without waiting for two Page 25 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL signal phases. This system also requires pedestrians to wait on a median in the middle of Charles Circle. With platoons of pedestrians exiting Charles/MGH Station, the median may not have adequate room for the large volume of pedestrians crossing, and promotes impatient pedestrian behavior. Requiring pedestrians to wait in the median also confuses drivers, who may think that they need to stop for pedestrians waiting to cross, which may lead to vehicular rear-end crashes. The crash data supports this concern, since 33% of the collisions at this location are rear-ends. Although many participants agreed that the two-phase signal is not ideal for a pedestrian crossing, one participant noted that there would have to be an exclusive signal for a continuous crossing, which would be difficult due to the multiple travel lanes merging together within the intersection. Creating an exclusive pedestrian crossing may impact traffic flow and lead to more congestion along Storrow Drive, which already is given less priority than Cambridge Street. Enhancements: Evaluate placing alarms on the emergency exit doors to restrict pedestrians from using this exit. Work with MBTA police to discourage use of the emergency exit doors to restrict pedestrians from using this exit. Investigate station enhancement and design to discourage use of emergency exit doors and provide a more direct path to the regular doors. Investigate the use of a pedestrian bridge from the station to the northern side of Cambridge Street to facilitate pedestrian operations and minimize conflicts with vehicular traffic. Evaluate conversion of the existing Cambridge Street median east of the Charles/MGH station as a traversable median with pedestrian crossing to allow pedestrians to cross over to MGH on the east side of the Charles/MGH station. Evaluate signal phasing, turning, and timing, and pedestrian recall at the southern crossing. Evaluate pedestrian crossing for ADA compliance and feasibility of adding tactile pads and ramps. Safety Issue #3: Pedestrian Crossing Infrastructure Observations: The placement of the pedestrian signal push-button is out of the way for people exiting Charles/MGH Station, dis-incentivizing its use. This signal is also problematic as it is on the left side of the crosswalk, while pedestrians should remain on the right side of the crosswalk when crossing. The overall placement of the post is not designed to lead pedestrians to behave properly within the crosswalk and may even promote pedestrians to cross outside of the crosswalk entirely and not pay attention to the push button and walk signal, resulting in dangerous behavior. Page 26 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Crosswalk and pedestrian signal on Charles Street Some participants also noted that the pedestrian signal added at the end of Charles Street on the south side of Charles Circle may be encouraging a lack of signal compliance by pedestrians at this location. Field observation showed only a small volume of traffic entering Charles Street from the circle, leaving pedestrians waiting an unnecessary amount of time in between walk signals. Participants observed an eight second walk time with hardly any turning traffic at this location. Enhancements: Evaluate locations of pedestrian signal push buttons at all signalized crosswalks. Provide more pedestrian way-finding signs and guidance. Evaluate signal phasing, timing, and pedestrian recalls, particularly for the crossing at Charles Street south of Charles Circle. Consider eliminating the pedestrian signal and adding a mid-street “Yield to Pedestrians” sign and informational signs telling pedestrians where to look for approaching vehicles entering Charles Street. Safety Issue #4: Visibility Observations: Participants discussed a potential visibility problem created by the Charles/MGH station for vehicles approaching Charles Circle from Cambridge Street. As there is a sharp turn to the left where Charles Street passes by the station, drivers may not be able to see pedestrians exiting out of the station and intending to cross Cambridge Street. This visibility issue also affects vehicular Vehicles approaching intersection from Storrow operations as eastbound traffic passing Drive eastbound through the barrels by Charles/MGH Station intersects with traffic approaching from Cambridge Street. This may contribute to both angle collisions and rear-end collisions as westbound vehicles on Cambridge Street or eastbound vehicles travelling under the station stop short for pedestrians. Participants also stated concern over the visibility of signals in Charles Circle as vehicles approach from the Storrow Drive eastbound off-ramp; contributing factors include a sharp curve with no Page 27 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL overhead signals, the length of the intersection, and observed red light running during turning movements. These vehicles are approaching the two-stage crosswalk, where participants displayed concern that drivers may bypass the stop line or run a red light. Enhancements: Enforce crosswalk laws and educate pedestrians to obey walk signals. Evaluate required signal visibility for all intersection approaches including MUTCD suggestions for proper placement of one per lane overhead on the far side of the intersection Evaluate signal clearance timings to address red light running at the intersection. Safety Issue #5: Southbound Left Turn Conflicts Observations: There is a potential conflict when vehicular traffic within Charles Circle turns left toward the median island south of the Charles/MGH Red Line station. Drivers who attempt this maneuver incorrectly become in conflict with the two-phase pedestrian signal across Cambridge Street. These pedestrians should be protected, but become at risk when vehicles are in the wrong lanes and are not under the correct signals for the View as approaching from Longfellow turning movements they wish to make, southbound/Storrow Drive eastbound putting them at odds with the pedestrian crossing. It was noted by some audit participants that congestion at the Cambridge Street/Grove Street intersection to the east, as well as for vehicles attempting to enter an MGH parking garage on Grove Street, may be spilling back into Charles Circle, resulting in drivers improperly navigating around the median island south of the Red Line station to avoid vehicle queues. The circle’s complex geometry, closely spaced intersections, and proximity to multiple destinations all contribute to make turning in this area difficult for drivers. Through written comments on the draft of this report, a participant noted that GPS navigation may not be able to provide directions in a timely manner for drivers to make accurate turning movements. Enhancements: Evaluate removal of island and signal operations to provide better clarity of operations. Evaluate timing at Cambridge/Grove Street and MGH garage operations to reduce upstream congestion on Cambridge Street spilling back into Charles Circle. Review road design to simplify turning movements within Charles Circle. Page 28 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Safety Issue #6: Wayfinding Challenges Observations: There are two northbound lanes within Charles Circle for one-way travel onto the Storrow Drive westbound on-ramp and three northbound lanes within Charles Circle for one-way travel onto Charles Street northbound. Navigating the intersection may be challenging for both regular commuters and out-of-town drivers, due to the intersection geometries, the three barrels underneath the MBTA station, and the plethora of destination points to be made from Charles Circle. One-way lanes under Longfellow Bridge on the north side of Charles Circle Participants observed a lack of lane utilization and confusion over the intended direction among drivers, for both southbound and northbound traffic. This is also a problem with vehicles entering Charles Circle from Cambridge Street and turning left onto these one-way approaches against traffic. Similarly, cars coming off of Storrow Drive westbound do not know if they have an entire lane under Longfellow Bridge or are merging with Charles Street traffic, resulting in lack of lane utilization. Unclear markings and signage of one-way travel under the bridge poses an immediate safety concern. A participant noted that there may also be information overload from the guide signage. Driver confusion and error not only contributes to vehicle crashes, but crashes with pedestrians and cyclists. Another current challenge to wayfinding in Charles Circle is that it is part of the work zone for the Longfellow Bridge Rehabilitation Project. Traffic signal operation has been temporarily modified to accommodate bridge construction sequencing, which may present new challenges for vehicles entering the intersection. Enhancements: • Evaluate signage and lane markings, such as installing arrows at the stop bar, and the addition of more “Do Not Enter” signs to better clarify lane operation within Charles Circle. • Evaluate lane re-assignment for Storrow Drive under Longfellow Bridge. • Consider the implementation of a modern traffic signal system to manage operational capacity due to new lane assignments. • Evaluate removal of the middle barrel and merge lanes for Charles Street and Storrow Drive eastbound. • Evaluate consolidation of the Storrow Drive right turning lane. Page 29 Road Safety Audit—Leverett Circle/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Safety Issue #7: Emergency Response Observations: Participants were concerned about the inability to determine the route of emergency response vehicles and approaching ambulances in the Charles Circle area. With MGH and other medical facilities in close proximity this poses a particular safety concern in this area. Enhancements: Evaluate emergency pre-emption equipment and GPS technology for the Charles Circle area. Emergency vehicles entering Charles Circle Recommendations After the site visit, audit participants returned to discuss the safety issues and consider various improvements. The audit participants were encouraged to consider both short and long-term improvements for each of the existing safety issues. Each improvement considered has been categorized as short-term, mid-term, or long-term based on the definitions shown in Table 2. Additionally, a cost category has been assigned to each improvement based on the parameters set forth in Table 2. Table 2. Estimated Time Frame and Costs Breakdown Time Frame Costs Short-Term <1 Year Low <$10,000 Mid-Term 1-3 Years Medium $10,001-$50,000 Long-Term >3 Years High >$50,000 Summary of Road Safety Audit A summary of the potential recommendations discussed by the RSA audit team are summarized in Table 3. The recommendations are summarized based on the potential safety payoff, time frame, approximate cost and potential responsible agency. The safety payoff is a subjective judgment of the potential effectiveness of the safety recommendations listed below. Page 30 Road Safety Audit—Leverett/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Table 3. Potential Safety Enhancement Summary Safety Issue Potential Safety Enhancement Safety Payoff Time Frame Cost Responsible Agency Leverett Circle Pedestrian Crossing and Wayfinding Evaluate pedestrian crossing phasing and timings on the southern side of Leverett Circle Medium Mid-Term Low DCR Pedestrian Crossing and Wayfinding Consider providing a crossing between the northeastern side of the O’Brien Highway/Nashua Street/Storrow Drive intersection and the island between the Charles Street approaches Medium Long-Term Medium DCR Pedestrian Crossing and Wayfinding Consider introducing traffic calming measures approaching the intersection High Long-Term High DCR/MassDOT Pedestrian Crossing and Wayfinding Evaluate impacts of restricting eastbound right turn to Storrow Drive to ‘No Right Turn on Red” permanently High Mid-Term Low DCR/MassDOT Pedestrian Crossing and Wayfinding Consider replacing illuminated “No Right Turn on Red” sign with red arrows and supplemental right turn restriction signage Low Long-Term Medium DCR Pedestrian Crossing and Wayfinding Consider restricting right turns on red when the western crosswalk spanning O’Brien Highway has a protected crossing Medium Short-Term Low DCR Pedestrian Crossing and Wayfinding Consider providing wayfinding signage from Science Park Station to the Museum of Science Low Mid-Term Low DCR Pedestrian Crossing and Wayfinding Consider restricting the southbound left turn from Nashua Street at O’Brien Highway and require all left turns to access Leverett Circle via the Nashua Street connection opposite Charles Street High Long-Term Medium DCR/MassDOT Pedestrian Crossing and Wayfinding Evaluate moving pedestrian warning signage to a more optimal location to increase visibility Low Short-Term Low DCR Pedestrian Crossing and Wayfinding Evaluate placing a flashing yellow arrow (FYA) indication for vehicles turning right onto Storrow Drive westbound from O’Brien Highway Low Mid-Term Medium DCR Page 31 Road Safety Audit—Leverett/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Safety Issue Potential Safety Enhancement Safety Payoff Time Frame Cost Responsible Agency Pedestrian Crossing and Wayfinding Evaluate options for standard signage at Leverett Circle and consider removing all nonstandard signage, including warning signs related to pedestrian movements Low Mid-Term Low DCR Pedestrian Crossing and Wayfinding Consider the proposed Pedestrian Overpass Bridge at Leverett Circle (MassDOT Project 606703) to improve pedestrian circulation High Long-Term High MassDOT Bicycle Operations Consider providing exclusive bicycle lanes High Long-Term High DCR Bicycle Operations Consider providing bike boxes at the traffic signals Medium Mid-Term Medium DCR Bicycle Operations Consider providing safe bicycle connections through the intersection High Long-Term High DCR Lane Usage Consider providing revised guide signs, which may incorporate diagrammatic lane usage, in advance of Leverett Circle High Mid-Term Medium DCR/MassDOT Lane Usage Consider providing route guidance pavement markings indicating the destination and appropriate usage for each lane in advance of Leverett Circle Medium Short-Term Low DCR Lane Usage Consider providing dotted lane extension lines at intersection locations High Mid-Term Low DCR Lane Usage Evaluate channelization of the O’Brien Highway eastbound right turn lane to Storrow Drive by means of plastic delineators Medium Mid-Term Medium DCR Advanced Warning Signage Consider providing signage in advance of the Storrow Drive ramp Medium Mid-Term Medium DCR/MassDOT Advanced Warning Signage Consider providing wayfinding signage for an alternate truck route to guide heavy vehicles away from Storrow Drive Medium Mid-Term Medium DCR/MassDOT Advanced Warning Signage Consider providing graphics “No Trucks” signage to supplement existing signage Low Short-Term Low DCR Advanced Warning Signage Consider providing active warning signs concurrently with a “Laser Detection” system on the Storrow Drive ramps High Long-Term High DCR/MassDOT Page 32 Road Safety Audit—Leverett/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Safety Issue Potential Safety Enhancement Safety Payoff Time Frame Cost Responsible Agency Low Short-Term Low DCR/MassDOT/ City of Cambridge Construction Impacts Encourage coordination between DCR, MassDOT, and the City of Cambridge to reduce delay caused by downstream construction projects during peak travel times Construction Impacts Review signal coordination and adjust signal timings accordingly Medium Mid-Term Medium MassDOT Roadway Geometry Evaluate realigning the westbound approach towards O’Brien Highway by narrowing from two lanes to one lane to allow the shifting of the raised median to the north Medium Long-Term High DCR Roadway Geometry Evaluate realigning the eastbound approach from O’Brien Highway through Leverett Circle to eliminate the offset Medium Short-Term Low DCR Roadway Geometry Consider providing dotted lane extension lines from O’Brien Highway to Leverett Circle Medium Short-Term Low DCR Roadway Geometry Consider providing additional wayfinding signage Low Short-Term Low DCR/MassDOT Storrow Drive Roadway Geometry Evaluate overall signage and sign placement and positions Low Short-Term Low DCR/MassDOT Roadway Geometry Evaluate lane configurations along Storrow Drive High Long-Term High DCR/MassDOT Roadway Geometry Evaluate switching to right side exits and entrances on Storrow Drive High Long-Term High DCR/MassDOT Roadway Geometry Evaluate creating a Storrow Drive eastbound direct on-ramp from Charles Circle to the I-93 access tunnel High Long-Term High DCR/MassDOT Roadway Geometry Evaluate grade separation of Storrow Drive High Long-Term High DCR/MassDOT Roadway Geometry Evaluate the relocation or removal of parking lot ingress/egress points on Storrow Drive ramps High Long-Term High DCR/MassDOT Roadway Geometry Evaluate softening the sharp reverse curves for both eastbound and westbound Storrow Drive by enlarging the radii High Long-Term High DCR/MassDOT Page 33 Road Safety Audit—Leverett/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Safety Payoff Time Frame Cost Responsible Agency Roadway Geometry Include bicycle prohibition signage at Storrow Drive entrances as a short-term measure until clarification of bicycle and pedestrian access along the Storrow Drive corridor is provided by DCR Low Short-Term Low DCR Single Vehicle Crashes Evaluate realigning Storrow Drive with fewer curves and remove/soften sharp radii High Long-Term High DCR/MassDOT Single Vehicle Crashes Evaluate use of a high-friction pavement surface High Mid-Term Medium DCR Single Vehicle Crashes Evaluate drainage system Medium Short-Term Low DCR Single Vehicle Crashes Evaluate the feasibility of creating boat sections on Storrow Drive to increase vertical clearance over bridge structures High Long-Term High DCR/MassDOT Single Vehicle Crashes Evaluate the relocation or removal of parking lot ingress/egress points on Storrow Drive ramps Medium Mid-Term Medium DCR/Mass Eye and Ear Single Vehicle Crashes Evaluate pavement marking type/condition along Storrow Drive Medium Mid-Term Medium DCR Sideswipe Collisions Consider guide sign improvements Low Short-Term Low DCR Sideswipe Collisions Remove/re-evaluate direct access to Storrow Drive from surface parking lots Medium Mid-Term Medium DCR/Mass Eye and Ear Sideswipe Collisions Evaluate use of a high-friction pavement surface High Mid-Term Medium DCR Sideswipe Collisions Consider pavement marking type/condition, possibly revising pavement marking lane lines to move traffic from sight distance obstructions High Mid-Term Medium DCR Sideswipe Collisions Evaluate drainage system Medium Short-Term Low DCR Vehicle Clearance Evaluate improved warning signage for low vertical clearance Low Short-Term Low DCR/MassDOT Vehicle Clearance Evaluate removal of numbered route designations along Storrow Drive Low Mid-Term Low DCR/MassDOT Vehicle Clearance Evaluate potential to increase roadway clearances along Storrow Drive High Long-Term High DCR/MassDOT Pedestrian Safety Evaluate the placement of a rapid rectangular flashing beacon (RRFB) at the Charles Street crossing at Fruit Street High Short-Term Medium MassDOT Safety Issue Potential Safety Enhancement Page 34 Road Safety Audit—Leverett/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Safety Issue Potential Safety Enhancement Safety Payoff Time Frame Cost Responsible Agency High Mid-Term Medium MassDOT Medium Long-Term High MassDOT/DCR Pedestrian Safety Evaluate placement of a raised crosswalk and /or curb extension Pedestrian Safety Consider improving visibility through road realignment and street tree placement Pedestrian Safety Enforce on-street parking restrictions Low Short-Term Low Boston Police Department Pedestrian Safety Evaluate relocating Fruit Street crosswalk while maintaining pedestrian desire lines High Short-Term Low MassDOT/DCR/ City of Boston Pedestrian Safety Evaluate adding another pedestrian connection over Storrow Drive, north of Longfellow Bridge and/or improving the Blossom Street footbridge to ADA compliance High Long-Term High MassDOT/DCR Charles Circle Bicycle Conflicts Clarify signs and markings within and in advance of Charles Circle Medium Short-Term Low MassDOT/City of Boston Bicycle Conflicts Evaluate the addition of a bike box and bike lanes or shared road bike markings on Cambridge Street Medium Short-Term Low MassDOT/City of Boston Bicycle Conflicts Investigate “innovative” geometric improvements to clarify traffic movements High Mid-Term Medium MassDOT/City of Boston Pedestrian Operations Evaluate placing alarms on emergency exit doors at Charles/MGH Station Low Short-Term Low MBTA Pedestrian Operations Work with MBTA police to discourage use of emergency exit doors Medium Short-Term Low MBTA Police Pedestrian Operations Investigate station enhancement and design to discourage emergency exit use Medium Mid-Term Medium MBTA Pedestrian Operations Investigate pedestrian bridge from station to northern side of Cambridge Street High Long-Term High MBTA/MassDOT Pedestrian Operations Evaluate the conversion of existing Cambridge Street median as a traversable median with pedestrian crossing to MGH Medium Mid-Term High MassDOT/City of Boston Pedestrian Operations Evaluate signal phasing, turning, timing, and pedestrian recall at the southern crossing Medium Short-Term Low MassDOT/City of Boston Page 35 Road Safety Audit—Leverett/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Potential Safety Enhancement Safety Payoff Time Frame Cost Responsible Agency Pedestrian Operations Improve pedestrian crossing for ADA compliance Medium Mid-Term Low MassDOT/City of Boston Pedestrian Crossing Infrastructure Evaluate locations of pedestrian signal push buttons Low Mid-Term Medium MassDOT/City of Boston Pedestrian Crossing Infrastructure Provide more pedestrian way-finding signs and guidance Medium Short-Term Low MassDOT/City of Boston Pedestrian Crossing Infrastructure Evaluate signal phasing, timing, and pedestrian recalls Medium Mid-Term Low MassDOT/City of Boston Pedestrian Crossing Infrastructure Consider eliminating the pedestrian signal and adding a mid-street “Yield to Pedestrians” sign and informational signs telling pedestrians where to look for approaching vehicles Medium Mid-Term Low MassDOT Visibility Enforce crosswalk laws and educate pedestrians to obey walk signals Low Short-Term Low City of Boston Police Visibility Evaluate required signal visibility for all intersection approaches Medium Short-Term Medium MassDOT/DCR/ City of Boston Visibility Evaluate signal clearance timings to address red light running Medium Short-Term Low MassDOT/DCR/ City of Boston Southbound Left Turn Conflicts Evaluate removal of island and signal operations High Long-Term High MassDOT/DCR Southbound Left Turn Conflicts Evaluate timing at Cambridge/Grove Street and MGH garage operations Medium Mid-Term Low City of Boston/MGH Southbound Left Turn Conflicts Review road design to simplify turning movements within Charles Circle High Long-Term High MassDOT/DCR Wayfinding Challenges Evaluate additional signage, lane markings (such as arrows at the stop bar), and “Do Not Enter” signs Medium Short-Term Low MassDOT/DCR Wayfinding Challenges Evaluate lane re-assignment for Storrow Drive under Longfellow Bridge Medium Mid-Term Low MassDOT/DCR Wayfinding Challenges Consider implementation of a modern traffic signal system to manage operational capacity due to new lane assignments. High Long-Term High MassDOT/DCR Safety Issue Page 36 Road Safety Audit—Leverett/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Safety Issue Potential Safety Enhancement Safety Payoff Time Frame Cost Responsible Agency Wayfinding Challenges Evaluate removal of middle barrel and merge lanes for Charles Street and Storrow Drive eastbound High Long-Term High MassDOT/DCR Wayfinding Challenges Evaluate consolidation of Storrow Drive right turning lane Medium Mid-Term Medium MassDOT/DCR Emergency Response Evaluate emergency pre-emption equipment and GPS technology Medium Mid-Term Low MassDOT/City of Boston Page 37 Road Safety Audit—Leverett/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Appendix A. RSA Meeting Agenda Road Safety Audit—Leverett/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Appendix B. RSA Audit Team Contact List Road Safety Audit—Leverett/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Participating Audit Team Members Date: June 18, 2015 Location: Starr Center, Massachusetts Eye and Ear Infirmary Audit Team Members Agency/ Affiliation Email Address Phone Number David Otte Massachusetts State Police David.otte@state.ma.us 508-820-2175 Joseph Borgomastro Massachusetts State Police Joseph.borgomastro@pol.ma Lisa Schletzbaum MassDOT Traffic Safety Lisa.schletzbaum@state.ma.us 857-368-9634 Tracy Osimboni MassDOT Tracy.osimboni@state.ma.us 857-368-9291 Doug Small MassDOT Douglas.r.small@state.ma.us 857-368-9623 Amitai Lipton MassDOT District 6 Amitai.lipton@state.ma.us 857-368-6313 Hameed Pervez MassDOT District 6 Hameed.pervez@state.ma.us 857-368-6307 Altaf Mulla Division of Capital Asset Management and Maintenance (DCAMM) Altaf.mulla@state.ma.us 617-727-4050 Wendy Landman WalkBoston wlandman@walkboston.org 617-367-9255 Mark Abbott CTPS mabbott@ctps.org David Loutzenheiser MAPC Alfredo Vilar Boston Transportation Department (BTD) Alfredo.vilar@boston.gov Caitlyn Duffy Representative Livingstone Caitlyn.duffy@MAHouse.gov Roch Larochelle HDR Roch.Larochelle@HDRInc.com 617-603-6344 Alexandria Siu Howard/Stein-Hudson (HSH) asiu@hshassoc.com 617-348-3346 James Barnack Jacobs James.Barnack@jacobs.com 617-532-4324 Peter Vasiliou Jacobs Peter.Vasiliou@jacobs.com 617-242-9222 Phil Viveiros McMahon Associates pviveiros@mcmahonassociates.com 617-556-0200 Allison Luff McMahon Associates aluff@mcmahonassociates.com 617-556-0200 Natalie Raffol McMahon Associates nraffol@mcmahonassociates.com 617-556-0200 dloutzenheiser@mapc.org 617-933-0743 Road Safety Audit—Leverett/Charles Circle, Boston Prepared by McMahon Associates, Inc. FINAL Appendix C. Detailed Crash Data