McGrath Boulevard Project Development
Working Group Meeting #4
August 5th, 2015– East Somerville Community School
Agenda
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Interim Improvements
Since We Last Met
Review of April Working Group Meeting
Roadway Design Approach
Design Options at Key Intersections
Working Group Activity
Next Steps
Interim Improvements
Interim Improvements
• Now underway
• Work for August 2015:
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Installation of signal conduit
Shifting curbs
Construction of new traffic island
Sidewalks and accessibility ramps
Excavation for Somerville Avenue punch-through
• Effort is generally on-time for completion this
construction season
Interim Improvements
Installation of Signal Conduit
Accessibility Improvements
Washington Street Island Expansion
Somerville “Punch Through”
Somerville Avenue “Punch Through”
Since We Last Met
Ongoing Public Involvement
• May 28th public information meeting
• June 4th Brickbottom residents’ briefing
• July 18th ArtBeat Festival appearance
Key Themes
• Strongly positive
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Excited about transformative project
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Working group
Project team
MassDOT
• Appreciation for efforts by:
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Alignment with shared priorities
Desire for connection and place-making
Concern for air quality and public health
Appreciation for separated bicycle facilities
April Working Group
Working Group Activity
Connectivity
Cross-Sections
Crossing the Corridor
• Peds/Bikes –
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Washington Street
Prospect Hill to Cross
Street
• Account for Bus Transit
(McGrath and
Washington Street)
Typical Sections – Common Themes
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Create a Greenway with a “Comm Ave” type configuration
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Dismissed pedestrian and bicycle use in the middle of the corridor
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Provide Bike Lanes Both Sides of corridor (at least one two-way)
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Desire for Parking On-Street (west side)
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Need to provide turning lanes at McGrath/Medford Street intersection
Roadway Design Approach
Roadway Design Approach
1. Identify road users and corresponding
volumes
2. Design critical intersections
3. Design roadway segments between key
intersections
4. Reevaluate and Return to Step 2
Design Volumes
2040 Design Volumes
Traffic Projections based on:
• CTPS Model
• Transportation Projects
• Planned Developments
• Mode Shift
• 4 and 6 Lane Build Scenarios
Transportation Improvements
1. Green Line
Extension/ Union
Square
2. Rutherford Avenue/
Sullivan Square
Local Development
1a. Green Line Extension:
Magoun Square
1b. Green Line Extension:
Gilman Square
1c. Green Line Extension:
Ball Square
2. Sullivan Square
3. River Green
4. Assembly Square
5. Beacon Street
6. Boynton Yards
7. Brickbottom/Inner Belt
8. East Somerville
Gateway
9. Fabrication District
10. Union Square
11. North Point
12. Wynn Casino
PM
AM
Mode Choice
CTPS Model – Regional Growth
2040 Build Scenarios
4 Lanes on McGrath with Rutherford Improvements
6 Lanes on McGrath with Rutherford Improvements
2040 Build Scenario - Diverted Traffic
Diverted Traffic
• CTPS Projections TwoLanes with Rutherford
Modified
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Up to 30% of traffic
is diverted
AM Design Volumes
PM Design Volumes
2040 Design Volumes
Traffic Projections based on:
• CTPS Model
• Transportation Projects
• Planned Developments
• Mode Shift
• 4 and 6 Lane Build Scenarios
Asked to consider:
• “Evaporated” Traffic
“Evaporated” Traffic
What is the concept of “evaporated”
traffic?
• Taking away road capacity can cause an overall
reduction in traffic volumes
How does traffic “evaporate”?
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Diverted Trips (CTPS Model)
Peak Hour Spread
Mode Shift
More Efficient Trips
Reduced Visitation to Area
Peak Hour Spread
I-93 (Southeast Expressway)
Peak Hour Spread - I
Existing McGrath Highway
Peak Hour Spread - II
Existing McGrath Highway
Peak Hour Spread - III
Future McGrath Boulevard
“Evaporated” Traffic - I
How were the studies conducted?
 “Disappearing traffic? The story so far”1
– 60 cases reviewed, primarily in Europe
– Broad study of traffic volumes for roadspace reallocation projects
» Planned, temporary maintenance closures, natural disasters
– Studied before and after traffic volumes with available data
» Impractical to capture all means of diverted traffic
 “Reclaiming City Streets for People” 2
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12 case studies identified by European Commission
Focused on livability and opportunities for regeneration in cities
Vauxhall Cross, London – Reduction of road capacity by 15%
Nuremberg, Germany – Full closure of through-route in city center
[1] Cairns et al.
[2] European Commission, Directorate-General for the Environment
“Evaporated” Traffic - II
How much can traffic be reduced?
 “Disappearing traffic? The story so far”1
– Median reduction: 11%
– Average reduction: 22%
 “Reclaiming City Streets for People” 2
– Vauxhall Cross, London, England:
» 2% - 8% reduction in peak
– Nuremberg, Germany:
» 23% reduction in city center in first year
• 4% - 19% increase on some surrounding roadways
» 5% overall reduction within outer ring in first year
» 9% overall reduction within outer ring in 12 years
[1] Cairns et al.
[2] European Commission, Directorate-General for the Environment
“Recondensed” Traffic
Octavia Boulevard, San Francisco, CA
 From Elevated Freeways to Surface Boulevards1
– 52% vehicle reduction (1995 to 2005)
» Central Fwy - 93,100 vehicles per day
» Octavia Blvd – 44,900 vehicles per day
Central Freeway (1964)
2.9%
Different Freeway
2.2%
2.1%
1.3%
Used City Streets
2.9%
Freeway / Transit
Combination
11.5%
No Longer Make Trip
Use Transit
Freeway / Street
Combination
77.0%
Freeway / Fewer Trips
combination
Source of Traffic Shifts Following Removal of San Francisco’s Central Freeway
Octavia Boulevard (2006)
[1] Cervero, Kang, Shively
Department of City and Regional Planning,
University of California, Berkeley
Design Traffic Volumes Conclusions
• Current research and case studies show a median
decrease of 11%
• Weekday AM (Critical Peak Hour)design volumes
are a:
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33% reduction from No Build volumes
19% reduction from Existing volumes
• Minimal additional volume reduction for
evaporation does not affect design
• Continue to push for lane reductions where
possible
“Evaporated” Traffic Test Case
What if we...
• Propose a 4 lane
McGrath crosssection at
Washington Street
• “Evaporate” traffic
volumes at the
intersection by an
additional 20%
“Evaporated” Traffic Volume Comparison
“Evaporated” Traffic Test Case
Then...
• Critical peak direction McGrath through
movements still operate with v/c ratios of
1.10 and 1.11
• Calculated queues on McGrath exceed 1000
feet
• Transit operation delay
• Bicycle and Pedestrian modes are impacted
by congested intersections
Design Options at Key Intersections
Key Intersections
McGrath Boulevard at Medford Street
Existing Conditions
• EB: 3 Lanes
• NB: 5 Lanes
• SB: 3 Lanes
McGrath Boulevard at Medford Street
McGrath Boulevard at Medford Street - I
McGrath Boulevard at Medford Street - II
McGrath Boulevard at Medford Street
Preliminary Findings
• Traffic Operations
• Overall LOS D or better during AM and PM peak hours
• V/C ratios for McGrath through movements do not exceed
1.08
• Geometric Configuration
• Two through lanes on McGrath Boulevard
• Cross-section recommended by the working group
• Narrowest point of corridor
McGrath Boulevard at Washington Street
McGrath Boulevard at Washington Street
Conventional Intersection – 6 Lane
McGrath Boulevard at Washington Street
Conventional Intersection – 6 Lane
McGrath Boulevard at Washington Street
Conventional Intersection – 6 Lane
McGrath Boulevard at Washington Street - 1
Conventional Intersection – 6 Lane
Preliminary Findings
• Traffic Operations
• Overall LOS E or better for AM and PM peak hours
• V/C ratios do not exceed 1.04 for McGrath approaches
• McGrath Boulevard movements expected to operate at LOS E
or better
• Geometric Configuration
• 6 lane cross-section on Washington Street at intersection
• Historic and existing buildings
• MBTA underpass
• Relocation of existing transit stops
• Joy Street diversion still occurs
McGrath Boulevard at Washington Street - 2
Continuous Flow Intersection
Proposed Location at I-75 and SR 884 Interchange in Lee County, Florida
McGrath Boulevard at Washington Street - 3
Continuous Flow Intersection
Advantages
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Improved capacity (+ 15-30%)
Reduced delay and travel time (- 20-90%)
Eliminate left-turn arrow phase
May prevent the need to add lanes
Disadvantages
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Cost (+ 25-50% more than traditional intersection)
Less pedestrian friendly
Strict access control
Initial driver confusion
McGrath Boulevard at Washington Street - 4
Continuous Flow Intersection
McGrath Boulevard at Washington Street - 5
Continuous Flow Intersection
McGrath Boulevard at Washington Street - 6
Continuous Flow Intersection
Existing Intersection
McGrath Boulevard at Washington Street - 7
McGrath Boulevard at Washington Street - 8
Continuous Flow Intersection
McGrath Boulevard at Washington Street - 9
Continuous Flow Intersection
McGrath Boulevard at Washington Street - 10
Continuous Flow Intersection
Preliminary Findings
• Traffic Operations
• Overall LOS D during AM and PM peak hours
• Potentially confusing operations
• Complicated queue management
• Geometric Configuration
• Allows for 4 lane on McGrath Boulevard cross-section
• Several geometric constraints
• Roadway extends larger than conventional intersection
• Unconventional bicycle and pedestrian accommodations
• Relocation of existing transit stops
Somerville Ave/ Medford St/ Poplar St
Somerville Ave/ Medford St/ Poplar St - 1
5 Leg Intersection Alternatives
Somerville Ave
Poplar Street
Connection
Medford Street
Poplar Street
Connection
Poplar Street
Jug Handle
Somerville Ave/ Medford St/ Poplar St - 2
Dual Intersection Alternatives
Full Access w/
Jug Handle
Medford Street
Right In/Right Out Access
Somerville Ave/ Medford St/ Poplar St - 3
Dual Intersection Alternatives
Medford Street/
Poplar Street 4-Way
Somerville Avenue/
Poplar Street 4-Way
Somerville Ave/ Medford St/ Poplar St - 4
Somerville Avenue Extension
5 Leg Intersection
Dual Intersection
Somerville Ave/ Medford St/ Poplar St - 5
5 Leg Intersection Alternative
Somerville Ave/ Medford St/ Poplar St - 6
5 Leg Intersection Alternative
Somerville Ave/ Medford St/ Poplar St - 7
5 Leg Intersection Alternative
Somerville Ave/ Medford St/ Poplar St - 8
5 Leg Intersection Alternative
Preliminary Findings
• Traffic Operations
• Overall LOS F during the AM peak hour
• Requires many signal phases
• Geometric Configuration
• Consolidated signalized intersection
• 6 lane McGrath Boulevard cross-section at intersection
• Access between Union Square and Brickbottom
• Several geometric constraints
• MBTA underpass
• Existing buildings and land use
• Historic building and pump station
Somerville Ave/ Medford St/ Poplar St - 9
Dual Intersection Alternative
Somerville Ave/ Medford St/ Poplar St - 10
Dual Intersection Alternative
Somerville Ave/ Medford St/ Poplar St - 11
Dual Intersection Alternative
Somerville Ave/ Medford St/ Poplar St - 12
Dual Intersection Alternative
Somerville Ave/ Medford St/ Poplar St - 13
Dual Intersection Alternative
Preliminary Findings
• Traffic Operations
• Overall LOS D or better during AM and PM peak hours
• McGrath V/C ratios do not exceed 1.06
• Side street movements operate at LOS F
• Requires queue management
• Geometric Configuration
• Able to provide a 5 lane McGrath Boulevard cross-section
• Less direct connectivity between Union Square and
Brickbottom
• Several geometric constraints
Working Group Activity
Working Group Activity
McGrath at Washington Street
McGrath at Somerville Avenue/Medford Street/Poplar Street
Working Group Activity
• Evaluate preliminary designs
– Pros & Cons
• How to incorporate
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Transit
Pedestrians
Bicycles
NEXT STEPS
Next Steps
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Advance the Intersection Design
Develop Ped/Bike Options Along Corridor
Quantify Impacts of Diversions
Identify Improvements for Impacted Intersections
Pedestrian and Bike Infrastructure & Analysis
Pedestrian and Bicycles
• Maximizing Capacity within Cross-Section for
• Pedestrians
• Bicycles
Transit
Where We Are
Schedule/Timeline
• Next working group session:
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Fall 2015
Stakeholder group briefings available upon request
QUESTIONS/DISCUSSIONS