THE IMPACT OF SACRAMENTO STATE’S ELECTRONIC BILLBOARD ON
TRAFFIC AND SAFETY
Mahesh Pandey
B.S., Panjab University, India, 1990
PROJECT
Submitted in partial satisfaction of
the requirements for the degree of
MASTER OF SCIENCE
in
CIVIL ENGINEERING
at
CALIFORNIA STATE UNIVERSITY, SACRAMENTO
SUMMER
2010
THE IMPACT OF SACRAMENTO STATE’S ELECTRONIC BILLBOARD ON
TRAFFIC AND SAFETY
A Project
by
Mahesh Pandey
Approved by:
__________________________________, Committee Chair
Kevan Shafizadeh, Ph.D., P.E., PTOE
__________________________________, Second Reader
Nicholas Compin, Ph.D.
____________________________
Date
ii
Student: Mahesh Pandey
I certify that this student has met the requirements for format contained in the
University format manual, and that this project is suitable for shelving in the Library
and credit is to be awarded for the Project.
__________________________, Graduate Coordinator
Cyrus Aryani, Ph.D., P.E., G.E.
Department of Civil Engineering
iii
________________
Date
Abstract
of
THE IMPACT OF SACRAMENTO STATE’S ELECTRONIC BILLBOARD ON
TRAFFIC AND SAFETY
by
Mahesh Pandey
This project is an applied research paper to evaluate the traffic and safety
impacts of a new electronic billboard owned by California State University,
Sacramento near Highway 50. This project analyzed traffic flow, speed, and lane
occupancy for two months before and after the installation of the electronic
billboard. Similarly, incident data for one year before and after its installation were
compared.
All of the required freeway performance data (flow rate, speed, and lane
occupancy) including incident data were downloaded from the online California
Freeway Performance Measurement System (PeMS) database. A review of previous
research was conducted to identify the best methodology for this study. Traffic
performance data were analyzed on Wednesdays during morning and afternoon twohour peak periods for two months before and after the installation of the electronic
billboard. The crash analysis was completed for a period of one year before and
after the installation of the electronic billboard. Public opinion data from an oncampus intercept survey were obtained from the Department of Civil Engineering at
Sacramento State.
The results indicate that the presence of an electronic billboard does not
appear to have a negative impact in traffic performance (flow, speed, and lane
occupancy) or incidents on the study section of the freeway based on the data
analyzed. More than two-thirds of the individuals surveyed who drive past this
billboard regularly believed that the electronic billboard near the campus does not
pose a safety risk to traffic.
_______________________________, Committee Chair
Kevan Shafizadeh, Ph.D., P.E., PTOE
_______________________
Date
iv
ACKNOWLEDGEMENTS
I would first like to thank my advisor Dr. Kevan Shafizadeh of the
Department of Civil Engineering at California State University, Sacramento (CSUS)
for his encouragement, valuable guidance, and support for completing this research
project and all my coursework. I am indebted to Dr. Nick Compin of Caltrans for his
valuable suggestions and cooperation. I am thankful to Dr. Ramzi Mahmood, the
Department chair, and Dr. Cyrus Aryani, the graduate coordinator, for their
cooperation with this project as well as all the professors at CSUS who prepared me
to reach to this stage. I would like to thank the California Freeway Performance
Measurement System (PeMS) for providing necessary data and the CSUS Library
for providing necessary information for this project. I thank all my classmates,
colleagues at County of Sacramento, and friends for their support and
encouragement. I thank my mom and my family members for their support and
encouragement.
I would like to give my special thanks to my wife Chhaya, daughter
Sadikshya, and son Amesh whose patience and love enabled me to complete this
work.
v
TABLE OF CONTENTS
Page
Acknowledgements .....................................................................................................v
Chapter
1. INTRODUCTION ................................................................................................1
2. BACKGROUND ..................................................................................................7
Federal.............................................................................................................8
California and Other States .............................................................................9
The Sacramento State Billboard ...................................................................10
3. LITERATURE REVIEW....................................................................................12
4. DATA .................................................................................................................16
Traffic Data ...................................................................................................16
Errors ...........................................................................................................18
Incident Data .................................................................................................20
Public Opinion ..............................................................................................22
5. METHODOLOGY .............................................................................................23
Traffic Performance ......................................................................................23
Incidents ........................................................................................................26
Public Opinion ..............................................................................................27
6. ANALYSIS AND RESULTS .............................................................................28
Traffic Performance Analysis .......................................................................28
Incident Analysis ..........................................................................................33
Public Opinion ..............................................................................................35
7. CONCLUSIONS AND RECOMMENDATIONS ..............................................38
Limitations ....................................................................................................38
Future Research ............................................................................................39
Appendix A ...............................................................................................................41
Appendix B ...............................................................................................................45
Appendix C ...............................................................................................................47
Appendix D ...............................................................................................................61
References .................................................................................................................76
vi
LIST OF TABLES
Page
1. Table 1 Eastbound Traffic Measures: Wednesdays Oct to Nov 2007 and 2008 ............ 32
2. Table 2 Westbound Traffic Measures: Wednesdays Oct to Nov 2007 and 2008 ........... 33
3. Table 3 Crash Rate Analysis ........................................................................................... 34
4. Table 4 Eastbound Incident Data- Aug. 2007 to July 2008 ............................................ 61
5. Table 5 Eastbound Incident Data- Aug. 2008 to July 2009 ............................................ 63
6. Table 6 Westbound Incident Data- Aug. 2007 to July 2008 ........................................... 66
7. Table 7 Westbound Incident Data- Aug. 2008 to July 2009 ........................................... 70
vii
LIST OF FIGURES
Page
1. Figure 1 Sacramento State’s Electronic Billboard ........................................................... 3
2. Figure 2 Vicinity Map...................................................................................................... 5
3. Figure 3 Locations of Known Electronic Billboards ....................................................... 7
4. Figure 4 States and Local Governments Limiting Billboards.......................................... 8
5. Figure 5 Location of Detectors on Highway 50 Study Section ...................................... 18
6. Figure 6 Postmile ............................................................................................................ 21
7. Figure 7 Respondents’ Driving Frequency Through Study Segment ............................. 35
8. Figure 8 Electronic Billboard Recognition by Drivers ................................................... 36
9. Figure 9 Respondents’ Opinion on Distraction .............................................................. 37
10. Figure 10 Respondents’ Opinion on Safety Risk ............................................................ 37
11. Figure 11 October 2007 Eastbound Traffic .................................................................... 47
12. Figure 12 November 2007 Eastbound Traffic ................................................................ 48
13. Figure 13 October 2007 Westbound Traffic ................................................................... 49
14. Figure 14 November 2007 Westbound Traffic ............................................................... 50
15. Figure 15 October 2008 Eastbound Traffic .................................................................... 51
16. Figure 16 November 2008 Eastbound Traffic ................................................................ 52
17. Figure 17 October 2008 Westbound Traffic ................................................................... 53
18. Figure 18 November 2008 Westbound Traffic ............................................................... 54
19. Figure 19 Oct - Nov 2007 Eastbound Relationship Among Basic Parameters............... 55
20. Figure 20 Oct - Nov 2008 Eastbound Relationship Among Basic Parameters............... 56
21. Figure 21 Oct - Nov 2007 Westbound Relationship Among Basic Parameters ............. 57
22. Figure 22 Oct - Nov 2008 Westbound Relationship Among Basic Parameters ............. 58
23. Figure 23 Comparison of Eastbound Traffic (Wednesdays October to November) ....... 59
24. Figure 24 Comparison of Westbound Traffic (Wednesdays October to November) ..... 60
viii
1
Chapter 1
INTRODUCTION
Highway 50 is a major highway extending from Interstate 80 (I-80) in West
Sacramento through the Sacramento, California metropolitan area to the state of
Maryland. Highway 50 near California State University, Sacramento (“Sacramento
State”) is an eight-lane freeway with adjacent interchanges at 65th Street and Howe
Avenue. A full auxiliary lane exists in each direction between interchanges at 65th
Street and at Howe Avenue.
Highway 50 serves an important transportation corridor, linking downtown
Sacramento with suburban areas to the east. Growth in the corridor is expected to
continue, as suburban development occurs in the eastern portions of unincorporated
Sacramento County, the City of Rancho Cordova, the City of Folsom, and El Dorado
County. The Sacramento Area Council of Governments (SACOG) has identified the
City of West Sacramento, Downtown Sacramento, Power Inn/South Watt area,
Mather/Rancho Cordova area, Aerojet area, and South Folsom area as locations of
high growth (SACOG, 2010). Any disturbances or improvements in traffic
conditions on Highway 50 can have a significant impact on the lives of many people
in the greater Sacramento area.
Any distraction (internal or external to vehicle) is a frequently cited factor in
increasing crashes (Farbry, et al., 2001). Mobile phones, music devices, and global
positioning system (GPS) devices are some examples of internal factors. The
2
external factors can include other vehicles on the road, construction or other
activities on or adjacent to the road, billboards, shop fronts, and even public art
installations adjacent to the roadway. Roadside advertising on electronic billboards
is one external source designed to attract the attention of drivers and road users.
Further, electronic billboards were cited as a cause of driver distraction during a
national safety summit hosted by U.S. Transportation Secretary Ray LaHood in
Washington, D.C. (Scenic America, 2010).
Electronic billboards are becoming a popular means of advertising and
providing public information alongside highways. With the application of light
emitting diode (LED) technology and computer controls, electronic billboards today
can display high quality images and have the capability of updating and displaying
new images frequently, typically every six to eight seconds (OAAA, 2009).
Electronic billboards on the side of highways have been useful for federal, state, and
local law enforcement to display time-sensitive information like traffic conditions,
directions/instructions during emergency evacuations, and Amber Alert child
abduction bulletins (OAAA, 2009). Law enforcement and other public safety
officials can use electronic billboards to reach mass audiences of drivers quickly.
This project is an applied research paper to evaluate the traffic and safety
impact of a new electronic billboard near Sacramento State adjacent to Highway 50.
This project involves an analysis of traffic flow parameters on upstream portions of
electronic billboard on both directions of Highway 50 near Sacramento State before
and after the installation of the new electronic billboard in August 2008 (as shown in
3
Figure 1). This project analyzed data from the California Freeway Performance
Measurement System (PeMS) database for changes in common traffic flow
parameters: speed, flow rate, and lane occupancy over a two-month period before
and after the installation of the electronic billboard. This project also analyzed crash
and collision data from PeMS for changes in non-injury, injury, and fatal crashes (if
any) over a one-year period before (August 2007- July 2008) and a one-year period
after (August 2008- July 2009) the installation of the electronic billboard. This
project will contribute to similar ongoing research studies to help road authorities
(e.g., State Departments of Transportation) identify the traffic and safety impacts of
the electronic billboards adjacent to freeways.
Figure 1: Sacramento State’s Electronic Billboard
4
The 48-foot by 14-foot electronic billboard was constructed at the south end
of Sacramento State near Highway 50 (Figure 2) and it has been operating since
August 2008. The electronic billboard uses LED technology with the capability of
eliminating glare. It also adjusts with the varying light levels of different times of
day and weather conditions so that the billboards are not unreasonably bright for the
safety of motorists. The display brightness is measured every two to three seconds,
and the sign automatically adjusts the brightness to control for ambient light
conditions every 30 seconds. This electronic billboard displays up to eight messages
every 64 seconds and has provided Sacramento State an opportunity to endorse
educational, social, and community programs. Besides the business advertisements,
it displays alert messages and emergency and disaster information as needed. In the
meantime, this particular electronic billboard was reportedly justified by the removal
of six other smaller billboards directly located around the University campus on
local city streets (University Enterprises, 2008).
5
N
Project location
Figure 2: Vicinity Map
(Source: Google Maps)
Like other electronic billboards, the Sacramento State electronic billboard
has embraced real-time capability in reaching people with important public message.
Even though the technology has evolved and modern billboards have become
innovative and versatile, roadside billboards are primarily designed to attract the
attention of drivers and road users. Any kind of distraction has the potential to
adversely affect traffic flow and become a factor for increasing crash rates.
Therefore, it is important to evaluate any impact of such external elements and their
significance on highway operations.
Moreover, a campus transportation intercept survey was conducted in May
2010, as a part of an annual evaluation of the campus transportation system. Along
with other transportation related questions, the on-campus opinion survey contained
6
questions on distraction and safety due to Sacramento state’s electronic billboard on
Highway 50 near 65th Street. Responses to this survey are also included to evaluate
the public’s perception of safety towards this electronic billboard adjacent to
Highway 50.
7
Chapter 2
BACKGROUND
There are approximately 450,000 billboards installed across the United States
and about 1,800 of them are electronic billboards (Copeland, 2010). There were
approximately 400 electronic billboards in 2007 (Story, 2007). It is a fast-growing
sector of the outdoor advertising market. Even though the billboard industry claims
that the electronic billboards are not dangerous, not enough research has been done
in this field to conclude that they have no impact on the traffic flow and road safety.
Most of the states have adopted laws or regulations to allow electronic billboards
that display multiple images. Figure 3 is a map indicating the locations of known
electronic billboards in the U.S. One can see that there are more of these electronic
billboards in the midwest and northeast than in the western U.S.
Figure 3: Locations of Known Electronic Billboards
(Source: Scenic America, 2010)
8
Some states prohibit all billboards including Alaska, Hawaii, Maine, and
Vermont. Similarly, there are some states, where the states and local governments
are limiting electronic billboards along public roadways, as shown in Figure 4.
Nationwide about 1,500 cities and communities are prohibiting the construction of
electronic billboards (Scenic America, 2010). Therefore, it is important to
understand the trade-offs between the billboard advertiser’s need to grab driver’s
attention and the significance of its impact on the traffic stream and safety.
Ban on electronic billboards
Moratorium on new billboards
Considering moratorium on electronic billboards
Figure 4: States and Local Governments Limiting Billboards
(Source: USA TODAY, 2010)
Federal
While the demand for electronic billboards is increasing, electronic and
conventional billboards are heavily regulated. The Highway Beautification Act of
1965 and its amendments and regulations of state and local bodies are in place to
9
provide effective control of outdoor advertising. Electronic billboards fall under
these regulations. Local laws and ordinances must fulfill these overriding federal and
state guidelines. In 2007, the Federal Highway Administration (FHWA) relaxed a
rule against electronic billboards. To keep pace with technology, the FHWA has said
that roadside billboards could use “changeable message” technologies as long as
these signs do not scroll or flash (see Appendix A). The computer-controlled display
allows advertisers to change the advertisement slowly at the intervals that prevent
driver distraction. The electronic billboards typically switch still advertisement only
every four to ten seconds, however eight seconds is recommended (Appendix A).
California and Other States
A traditional billboard can contain only one advertisement at a time but an
electronic billboard can display multiple advertisements in a day. Electronic
billboards also allow advertisers to change their message as often as they want
because of its computerized operation method. As a result, electronic billboards can
generate more income than traditional billboards. Electronic billboards are attracting
state and local governments also, in this economic downturn, as a way to generate
significant revenue to help reduce the budget deficit.
In October 2008, California Department of Transportation (Caltrans) asked
the FHWA to allow the conversion of the state’s 692 traffic alert and message signs
to state-of-the-art electronic billboards so that they can be leased for business
advertisements when not in use for traffic information (Solof, 2009). Governor
10
Arnold Schwarzenegger also proposed an idea of converting overhead freeway
changeable message signs (CMSes) into electronic billboards. The Governor sees the
plan as a way to generate revenue and improve the technology of warning signs, but
critics fear the new signs would distract drivers and lead to more collisions
(Yamamura, 2010). If the Governor’s plan is approved, electronic billboards would
appear throughout California highways.
Massachusetts Bay Transportation Agency (MBTA) is auctioning off
space for sixty new electronic billboards along highways in eastern Massachusetts to
raise revenue (about $6 million per year) to support the Boston-area bus and train
network (Solof, 2009). The MBTA already has more than 200 electronic billboards
in place. Some communities and the Massachusetts state legislature are challenging
the sign, however many communities and state officials are looking for guidance
from the federal government.
The Sacramento State Billboard
Before the installation of the electronic billboard at Sacramento State, a local
neighborhood association, the College-Glen Neighborhood Association (CGNA),
opposed the installation of the electronic billboard. In a letter to the Sacramento
State administration, a member of the CGNA expressed concerns about the
electronic billboard with flashing advertisements; they believed it would create a
distraction for drivers and worsen safety on Highway 50 (see Appendix B). In
response, Sacramento State, through its auxiliary business arm University
11
Enterprises Incorporated (UEI), assured the CGNA that Caltrans reviewed its request
and issued a permit to allow the electronic billboard to be constructed. Further, the
University Enterprises clarified that the electronic billboard would not feature
animation, flashing lights, or full-motion video. Instead, the advertisement would
change image once every eight seconds without glare or light leakage (see Appendix
B).
The Sacramento State electronic billboard is situated to attract the attention
of motorists on Highway 50. This part of the freeway serves as a major access point
to Sacramento State, as well as a major corridor for commuters and general road
users to downtown Sacramento. While there is some concern that drivers can
become distracted, it is essential to determine if there is any negative impact on the
performance of traffic or safety due to the presence of this electronic billboard
adjacent to the freeway.
12
Chapter 3
LITERATURE REVIEW
This literature review focuses on the performance of traffic, safety impacts,
and the public perception of electronic billboards on the side of roadways. It is
intended to draw guidelines, methodology, and results from previous research to
assist in determining the impact of Sacramento State’s electronic billboard on traffic
and safety adjacent to Highway 50. There are few studies done in these subject areas.
The 1980 FHWA report “Safety and Environmental Design Considerations
in the Use of Commercial Electronic Variable Message Signage,” stated that no
credible statistical evidence existed to support the conclusion that electronic or
variable message signs negatively impacted road safety. However, incident studies
reported both positive and negative relationships between accidents, high driving
task demand, and the presence of roadside advertisements. The evidence was
statistically insufficient to support the relationship between electronic billboards and
traffic incidents. The FHWA research report was based on a critical review of
reported research, operational experience, and legislative history relating to
electronic billboards and outdoor advertising. The research report was intended to
provide background information for the development of standards for electronic
billboards used for public information and business advertisements adjacent to
roadways. The study pointed out various factors to be considered in any
13
development of standards for the design of electronic billboards and suggested more
studies be done in this field.
The FHWA has performed studies on a regular basis trying to find a
relationship between electronic signs and traffic safety. In 2001, the FHWA
published another report, “Research Review of Potential Safety Effects of Electronic
Billboards on Driver Attention and Distraction,” which reviewed the literature
published after the 1980 study. This research project followed the earlier FHWA
research in 1980 and reviewed the literature published after the 1980 study. This
report found the results to be mixed and inconclusive. However, the report noted
that, “studies were identified that verified that: an increase in distraction, a decrease
in conspicuity, or a decrease in legibility may cause an increase in the crash rate”
(page 8, Farbry, et al., 2001).
A research report titled “Traffic Safety Evaluation of Video Advertising
Signs” (Smiley et al., 2005) provided information on traffic performance and safety
in one section of urban expressway and three intersections. Besides eye fixation and
conflicts between driving and external distraction, the researchers studied flow, lane
occupancy, headway, speed, crashes, and public opinion to determine the change in
traffic parameters before and after electronic billboards were installed.
A study conducted by the Center for Automotive Safety Research at Virginia
Tech’s Transportation Institute concluded that electronic billboards were “safety
neutral,” based on a study of eye glance movements of 36 drivers in speciallyequipped vehicles in Cleveland (Lee, et al., 2007). Participants were told to drive on
14
interstates and surface streets to help understand the way people drive in a natural
environment. However, they were not informed about the true purpose of the
experiment (Lee, et al., 2007). The study examined driver performance in the
presence of electronic billboards, as compared to locations without billboards. They
studied drivers’ eye glance behavior towards billboards and digital signs and at
control sites without billboards or signs. Speed maintenance and lane-keeping were
also recorded. There were no significant differences in speed. The lane-keeping
performance was poorer but not significantly different.
Because there are not many studies done in this area, a study commissioned
by the FHWA recommended further research be done to identify the correlation
between electronic billboards and their risk to drivers (Story, 2007). In February
2009, FHWA published another research report, “The Effects of Commercial
Electronic Variable Message Signs (CVEMS) on Driver Attention and Distraction:
An Update,” which is an update of an earlier work of FHWA, and reviews the
research (post-hoc crash studies, field and laboratory investigations, previous
literature reviews, and reviews of practice) related to electronic billboards. The
research review found the results of previous literature reviews were inconclusive
(FHWA, 2009). Based on the literature review, FHWA proposed a long-term
program of research, which includes determination of distraction and basis for
possible regulation of electronic billboards. The FHWA studies recommended a
methodology for gauging driver distraction. It called for an “on-road instrumented
vehicle study,” which would identify changes in driving behavior at and around
15
billboard sites with on-board measurement devices in the vehicles of volunteer
drivers.
16
Chapter 4
DATA
Traffic Data
California Freeway Performance Measurement System (PeMS) has been set
up to collect real-time data from freeways in the State of California to compute
freeway performance measurements and to facilitate other traffic related studies.
This system can be accessed through the Internet at http://pems.dot.ca.gov.
PeMS collects the raw flow and lane occupancy data that comes from more
than 30,000 individual lane detectors every 30 seconds in California (PeMS, 2010).
Flow is expressed as the number of vehicles that crosses over a detector during a
given time period. It is measured in terms of vehicles per hour (vph) or vehicles per
hour per lane (vphpl). Lane occupancy is the percentage of time that a detector is
occupied in a given time of period and is a percentage that ranges from 0% to 100%.
The lane occupancy is commonly used as a surrogate for the density of the traffic
over a road segment. PeMS aggregates the lane-by-lane 30 second data into a single
number that represents the five-minute total of vehicle flow over all lanes at that
location. The five-minute data sample for flow is computed by summing the
individual 30 second data samples. For lane occupancy, the five-minute data sample
represents the weighted average over the 30-second data samples received, based on
the number of vehicles observed.
17
The majority of loop detectors in the state of California are single loop
detectors (Chen, et al., 2001). Speed can be measured directly from radar detectors,
but single loop detectors cannot measure speed. PeMS has ability to compute speed
for sensors that do not report speed, such as single loop detectors. Double loop
detectors are installed in specific spacing, which have the capability of measuring
vehicle speed, but PeMS does not use the speed measurements from double loop
detectors. PeMS research has shown that their speed calculation algorithm based
solely on the flow and lane occupancy are better than speed measured from double
loop detectors (PeMS, 2010).
Flow, lane occupancy, and speed data were downloaded from the PeMS
website then exported into an Excel spreadsheet. The detectors on the study section
were identified as sensor # 313684 for eastbound direction and sensor # 312205 for
the westbound direction (shown in Figure 5). At these locations, data were obtained
in five-minute intervals for the study period (October through November 2007 and
October through November 2008) in each direction for all lanes located on the study
segment (four lanes on each side).
18
N
CSUS
Sign Location
312205
Study Segment
Figure 5: Location of Detectors on Highway 50 Study Section
(Source: PeMS)
Errors
There are some possible sources of error, which can affect the data obtained
from PeMS. These errors may have some effect on the result of the freeway
performance analysis.

Detector health- The greatest potential for error comes from the detection
itself. The data quality depends on the detector health. Detector health
involves whether the detector actually measures data and sends it to the
controller. The detection problems can occur with failures at the sensors or
anywhere in the data transmission process. In absence of real time traffic
19
detector data, PeMS generates the imputed data to fill missing data, which
may be different from actual data from the working detector. The imputed
data may not be as accurate as data from working sensor. In this study, data
reported by detectors were generally 75% - 100%. There were few period
when detectors did not report any data, and those data-holes were filled by
imputed data. When detectors reported 0% data, the imputed data available in
the PeMS database were excluded in the analysis of before and after period
traffic measures in this report.

Varying traffic type- The traffic volume consists mostly of short passenger
cars (average length 16 feet) and long trucks (average length 60 feet). The
truck volumes estimated from the PeMS algorithms were not measured.
Truck volumes were estimated from five-minute aggregated volume and lane
occupancy data.

Incidents- Any incident at immediate downstream or upstream of the study
segment in the freeway could cause disruptions in the traffic flow, and the
data received during this period would affect the analysis. For example, an
incident or just downstream of the study segment can cause congestion on the
study segment on upstream of traffic flow, which affects the end result. On
the other hand, an incident upstream of the study segment causes low flow
for certain time followed by a surge in flow after a lane is reopened.
20
Incident Data
California Highway Patrol (CHP) has a well-maintained database and a
website to record and access incidents on state highways. PeMS has maintained a
system to interface with the CHP database and obtain the incident data to store in its
database. The incident data contains vehicle incidents information reported by CHP:
the time, the location, and the detail of the incident. PeMS also receives incident data
from Caltrans Traffic Accident Surveillance and Analysis System (TASAS), which
contains data on incidents (but not breakdowns) and the verified locations.
PeMS provides the collision data relative to the freeway postmile. California
uses a postmile system on all its highways to track highway mileage, which is
designated as the absolute postmile in the PeMS database. The absolute postmile is
the actual centerline distance along the freeway from the district boundary or the
western or southern end of the route. Similarly, the county route postmile starts at
the western or southern end of the route or the boundary of the county which
contains the highway and is a black marked rectangular white plate marked with a
county route number, county designation, and postmile (Figure 6). Mileage is
marked nearest to hundredths of a mile and postmiles are used as a reference base for
planning, design, maintenance, construction, and operation of the highway system in
California (California Highways, 2009). In this study, absolute postmile was
considered as a reference distance for analysis purpose along Highway 50 as given
in the PeMS database.
21
Figure 6: Postmile
(Source: California Highways, 2009)
The postmile of the electronic billboard needed to be identified and the crash
data was downloaded with respect to the postmile for the study periods from the
PeMS database. Current state statutes and regulations employ different values
ranging from 500 to 1,000 feet from intersections or interchange for placement of
billboards (FHWA, 2001). Based on this distance value, the half-mile (2,640 feet)
before the electronic billboard in each direction was considered for evaluation in this
study.
Sacramento State’s electronic billboard is located near absolute postmile 8.76
(distance from the beginning of the route). Crash data available on the PeMS website
for Highway 50 were downloaded from postmile 8.3 to postmile 8.9 in eastbound
direction and postmile 8.6 to postmile 9.2 in westbound direction of the posted
billboard for the period of one year before (August 2007 to July 2008) and one year
after (August 2008 to July 2009) the installation of the electronic billboard. The
22
before and after period incident data for eastbound and westbound direction are
given in Appendix D. The incidents on the study segments are shaded in the tables.
The postmiles given in the table are absolute distance from western end of Highway
50.
Public Opinion
Public opinion data was collected as part of an annual Campus
Transportation Intercept Survey at Sacramento State. The survey is conducted by
students in a transportation engineering course in the Department of Civil
Engineering (CE 147). Students in this course randomly stop individuals entering the
campus at major access points to ask questions about their trip to campus and their
general opinion of transportation services and facilities on campus. Surveys were
conducted on May 4 and 6, 2010. There were four questions directly related to the
electronic billboard. There were a total 484 respondents of this survey. There were
395 (81.6%) undergraduate students, 37 (7.6%) graduate students, 17 (3.5%) staff,
25 (5.2%) faculty, and 10 (2.1%) others.
23
Chapter 5
METHODOLOGY
In the research report “Traffic Safety Evaluation of Video Advertising Signs”
(Smiley et al., 2005), the traffic flow, lane occupancy, speed, crash data, and public
opinion were similar to the data used in this study. The study by Smiley et al.,
provided the basic methodology to study the impacts of Sacramento State’s
electronic billboard on traffic and safety.
Traffic Performance
In this study, the safety and traffic performance were analyzed from available
traffic data before and after the installation of the electronic billboard near
Sacramento State. Speed, flow, and lane occupancy data at the approach of the
billboard on Highway 50 in each direction was obtained from the PeMS database.
Because all the traffic data were primarily collected through the detectors on the
freeway, it was important to identify the location of detectors on the main traffic
stream at or nearest to the study segment. Detector locations (detector number) were
identified on Highway 50 on eastbound and westbound directions near the billboard.
Once the detector numbers were known, the five-minute interval speed, flow, and
lane occupancy data were downloaded into Excel from the PeMS database for a
period of two months before and after the installation of the sign in the month of
24
October to November 2007 and October to November 2008. The billboard was
commissioned on August 2008.
There were four lanes in each direction of the study segment. Speed, flow,
and lane occupancy were downloaded for each lane. The individual lane data was
averaged to compute the mean operating speed, flow per lane, and lane occupancy
per lane. PeMS records the hourly flow in five minutes increments. Therefore, the
five-minute average flows were converted to hourly flows multiplying by 12. Plots
of flow, speed, and lane occupancy were prepared to visualize the traffic
performance over the study period in each direction as shown in Figure 11 through
Figure 18 in Appendix C.
The data recorded on weekends and holidays were removed from the dataset
because the traffic operations are not similar on weekdays and weekends. On
weekdays, there exists more traffic, which is more sensitive to changes in driver
behavior. During the study period, there were four holidays observed. They were
Columbus Day, Veterans Day, and Thanksgiving (two days). The data from all
individual weekdays were combined into a single, “average weekday,” which
contained speed, flow, and lane occupancy in five-minute intervals. Average
weekday data were plotted as speed vs. flow, speed vs. lane occupancy and flow vs.
lane occupancy to find out any changes in travel pattern before and after the
electronic billboard was installed.
It was assumed that the low traffic volume and lane occupancy during the off
peak periods would be least affected by the electronic billboard. Only peak-hour
25
weekday conditions were analyzed. The study segment was analyzed for any change
in performance between 6:30 am to 8:30 am and between 3:30 pm to 5:30 pm. The
mean value of speed, flow, and lane occupancy and their standard deviations were
computed. Then the speed, flow, and lane occupancy and their standard deviations
were compared between the before and after periods to conclude if changes were
observed.
In this case, the study segment was analyzed for any change in performance
during the morning peak period (6:30 am to 8:30 am) and the afternoon peak period
(3:30 pm to 5:30 pm) during a typical weekday (Wednesday). Wednesday was
chosen arbitrarily, as it was the middle of the week and there were no holidays
during the study period. Moreover, traffic studies are generally conducted on
Tuesdays, Wednesdays, or Thursdays (Caltrans 2002). The times were chosen to
best capture the peak travel period, even though the time of the peak hour can vary
from day to day. This peak travel period is most important to a large number of
users. Therefore, the mean value of speed, flow, and lane occupancy, and their
standard deviations were computed during the morning and afternoon peak periods.
Then the speed, flow, and lane occupancy and their standard deviation, were
analyzed and compared before and after the electronic billboard was installed to
conclude if any changes occurred. For comparison of change in flow, speed, lane
occupancy, and their standard deviation, the percent change was calculated using the
following equation:
26
Percent Change, % 
( Final  Initial )
 100
Initial
Incidents
In the study of the Sacramento State electronic billboard, the post-hoc crash
study was considered where incident data was collected for one year prior to, and
one year after, operation of the electronic billboard. Vehicle incident data was
analyzed to compute the crash rate in each direction during the study period, and the
crash rates before and after the installation of the electronic billboard were compared
to conclude if changes had occurred.
The incident data for the study segment was analyzed and compared to
identify if any changes occurred on crashes during the before and after period. Crash
rate for collision investigation was calculated based on the number of crashes per
MVM (million vehicle miles) by the following equation:
Crash Rate per MVM, R 
a  1,000,000
ADT  l  d
where, a = total number of incidents in one year
l = length of segment in miles
d = number days (365) during study period, and
ADT = average daily traffic.
The incident data one year before and one year after the installation of the
electronic billboard were downloaded, and crash rates were compared for each
direction. The weekend and holidays were also included in the analysis. The study
27
segment was considered 2,640 feet (0.5 miles) to make the evaluation more
conservative and inclusive. Analysis was done for a segment of 0.5 miles before the
electronic billboard in each direction. To calculate the crash rate, the annual average
daily traffic (AADT) and the number of incidents in each direction were obtained
from the PeMS database.
Public Opinion
Public opinion survey data obtained from the Department of Civil
Engineering was a part of on-going evaluation of campus transportation system.
Only the electronic billboard related responses were included in this report for
analysis of opinions of the respondents. The responses were imported into an Excel
spreadsheet, and charts were prepared from the responses for quick visualization and
analysis purposes.
28
Chapter 6
ANALYSIS AND RESULTS
Traffic Performance Analysis
The PeMS database provided information for speed, lane occupancy
(surrogate for lane density), and flow for every five-minute interval throughout the
day. There are 288 intervals per day and 17,856 intervals over the course of two
months. To analyze these data, Excel spreadsheets were prepared. The mean and
standard deviation were calculated. The data analysis was carried out as outlined
below.
Flow, speed and lane occupancy against time were plotted to obtain a general
overview traffic operation during the study period in the study section as shown in
Appendix C (Figure 11 through Figure 18). The plots were real representations of
the total data (flow, speed and lane occupancy) obtained from PeMS database in
both directions. Moreover, each figure contained plots of flow, speed, and lane
occupancy against time, which made it easy to visualize and understand the nonuniformity of traffic on the holidays and on weekends compared to normal
weekdays. From the plots, a clear distinction could be made between the weekday
and weekend traffic flow patterns. The weekdays had higher peak flow and lane
occupancy, and lower speed compared to weekends and/or holidays. From the plots,
some data gaps were identified on November 22, 2008 in eastbound traffic (Figure
29
16 in Appendix C). From these figures, the westbound traffic was observed to have
more fluctuation in speed compared to eastbound traffic before and after the
installation of the electronic billboard. Further, on the same segment the detectors
did not report any data after November 22. So, the imputed data available on the
PeMS database was excluded from analysis. Greater variation in speed was observed
in 2007 for eastbound traffic in November compared to October (Figure 12, and
Figure 13 in Appendix C).
The five-minute data granularity of the weekdays were averaged to obtain
five-minute average values over the 24-hour for the study sections of the study
periods. Here the mean values (flow, speed, and lane occupancy) were determined at
the increment of five-minutes for a 24-hour period. These data were used to prepare
plots of speed vs. lane occupancy, speed vs. flow, and flow vs. lane occupancy in
five-minute interval on an average “average weekday” for both directions before and
after, as shown in Appendix C (Figure 19, Figure 20, Figure 21, and Figure 22).
These plots provided an overview of flow, speed, and lane occupancy with each
other. Further, each plot of the basic parameters in each direction before and after the
installation of the electronic billboard were observed to be similar. Based on these
plots, traffic operation in the study segment before and after the installation of the
billboard were not significantly changed in the same direction. However, in
westbound direction, for higher flow values, fluctuations in speed were higher than
in the eastbound direction.
30
Traffic performances (flow, speed, and lane occupancy) were analyzed for
two months before (October - November 2007) and after (October - November
2008) the installation of the electronic billboard. A typical analysis of the
Wednesday data was done. The five-minute data points of all Wednesdays were
averaged to obtain five-minute average values over the 24-hour period. These fiveminute average values of Wednesday data were used to prepare plots of flow vs.
time, speed vs. time, and lane occupancy vs. time for the eastbound direction (Figure
23) and westbound direction (Figure 24), given in Appendix C. These plots provided
real time comparison of flow, speed, and lane occupancy in each direction before
and after the installation of the electronic billboard during a typical weekday
(Wednesday) during the months of October and November. The change in traffic
operation parameters (flow, speed, and lane occupancy) before and after the
construction of the billboard could be visualized from these plots. The plots provided
an idea of the morning and afternoon peak periods and variations of traffic
throughout the day.
The mean and standard deviation of flow, speed, and lane occupancy over the
peak two hours in morning and in afternoon were computed and compared by
calculating the change in percentage of the after-period measured to the beforeperiod measure. A decrease in variance of speed may be anticipated to improve
safety; however, an increase in mean lane occupancy (i.e. decreased headway) and
increased speed variance would likely decrease safety (Smiley, et al., 2005). When
drivers get distracted they might slow, resulting in greater speed variability, or might
31
allow unsafe headways or lane occupancy to develop when they fail to react quickly
to detect the slowing of the vehicle in front of them. When lower headways develop,
there will be less reaction time, and the probability of collision will be higher.
Further, a typical analysis of flow, speed, and lane occupancy were done to
observe the variation in performance measures during morning and afternoon peak
periods in each direction before and after the installation of electronic billboard. In
the eastbound direction, the standard deviations (SD) of speed and lane occupancy
decreased with the increase in operating mean speed. The increase in speed (25%)
during afternoon, and increase in standard deviation (more than 75 %) during
morning and afternoon, as shown in Table 1 were unusual and could be the effect of
weather (rain), lane closures, or some event in the nearby area particularly on
November 2007, as shown in Figure 12. Even though the flow variation during
morning was higher after the installation of the electronic billboard, the speed and
lane occupancies were not impacted adversely. In the eastbound direction, vehicle
speeds, and lane occupancies, through the months of October and November on the
Wednesday peak periods after the installation of the electronic billboard, were not
found to be impacted (Table 1).
32
Table 1: Eastbound Traffic Measures: Wednesdays Oct to Nov 2007 and 2008
Morning Peak
(6:30 - 8:30 AM)
Afternoon Peak
(3:30 - 5:30 PM )
2007
2008
% Change
2007
2008
% Change
1,526
1,582
3.72
1,539
1,672
8.62
SD
145
159
9.78
154
119
-22.75
Mean
Speed, mph
53.4
62.9
17.76
46.1
57.7
25.09
15.7
1.8
-88.26
19.2
4.5
-76.38
11.82
11.74
-0.63
13.71
13.40
-2.28
2.06
1.33
-35.23
3.37
1.77
-47.47
Mean Flow,
vphpl
SD
Mean
Occupancy,
%
SD
Similarly, in the westbound direction vehicle speed, and lane occupancy,
through the months of November and December during the Wednesday morning
peak period after the installation of the electronic billboard, were found to be better
than the year before the installation of the electronic billboard during the same
period of time (Table 2). The standard deviations of flow, speed, and lane occupancy
decreased with the increase in the operation speed. However, standard deviations of
flow, speed, and lane occupancy increased during the afternoon peak period,
compared to before period measures. On the other hand, mean speed was higher with
the decrease in lane occupancy during the afternoon peak period. The increase in
flow variation was observed to have no significant adverse effect on operating speed
and lane occupancy.
33
Table 2: Westbound Traffic Measures: Wednesdays Oct to Nov 2007 and 2008
Morning Peak
(6:30 - 8:30 AM)
Afternoon Peak
(3:30 - 5:30 PM )
2007
2008
% Change
2007
2008
% Change
1,887
1,887
0.00
1,599
1,608
0.56
SD
212
192
-9.44
172
206
19.97
Mean
Speed, mph
51.6
54.3
5.29
43.5
46.8
7.67
9.9
9.5
-4.46
16.2
17.2
6.00
17.55
16.17
-7.85
19.47
18.03
-7.40
4.37
3.88
-11.26
7.53
8.11
7.76
Mean Flow,
vphpl
SD
Mean
Occupancy,
%
SD
Incident Analysis
The average daily traffic (ADT) was computed for both direction during the
study period as explained in the methodology for both direction and the duration of
study. The crash data downloaded from the PeMS website was sorted to identify the
number of incidents on the study segment in each direction during the study period
as shown in Appendix D (Table 4, Table 5, Table 6, and Table 7).
The crash rates (MVM) for the study segment were calculated using the
following equation as explained in the methodology. A sample of crash rate
calculation on eastbound direction for August 2007 to July 2008 is given below:
Rate per MVM, R 
a  1,000,000
ADT  l  d
34
where,
a, is the number of collisions in one year = 10
l, is the length of segment = 0.5 mile
d, is the number of days during study period = 365 days
ADT, is the average daily traffic = 88,424 vehicles (from PeMS data)
Sample calculation:
R
10 1,000,000
88,424  0.5  365
= 0.62 crashes per MVM
The total number of injury and non-injury incidents and the crash rates in one
year after the installation of the electronic billboard were found to be lower than in
the year before the installation of the electronic billboard in both directions. The
results show that the study segment 2,640 feet upstream from the electronic billboard
did not exhibit any increase in the crash rate compared to the year before the
installation of the electronic billboard in both directions, as seen in Table 3 below.
Table 3: Crash Rate Analysis
Eastbound
Westbound
Aug 07 – July 08
Aug 08 – July 09
Aug 07 – July 08
Aug 08 – July 09
AADT
88,424
77,806
94,338
93,543
Number of
Incidents
10
7
12
11
Crash Rate
(crashes/MVM)
0.62
0.49
0.70
0.64
35
Public Opinion
The on-campus survey results showed that a majority (69.2%) of the
respondents (333 out of 481) drove through the study segment. Among the survey
respondents who drove through the study segment, 24.9% (120) indicated they drove
past the electronic billboard daily, while 26.6% (128) indicated they drove past the
electronic billboard a few days a week. Another 11.0% (53) and 6.7% (32) indicated
that they drove past the electronic billboard weekly or monthly, respectively (Figure
7). A total of 333 respondents indicated that they drove through the study segment at
least monthly, among which 85.6% (285) noticed the electronic billboard while
driving through the study segment (Figure 8). The result indicates that the driver in
the study segment have high awareness of electronic billboard.
Figure 7: Respondents’ Driving Frequency Through Study Segment
36
Figure 8: Electronic Billboard Recognition by Drivers
Moreover, 285 participants in the survey responded to a question about the
potential distraction and safety risk of the electronic billboard. Among these
respondents, 34.7% (99) had expressed that the electronic billboard is distracting to
drivers (Figure 9), and 31.6 % (90), expressed that the electronic billboard poses a
safety risk to traffic (Figure 10). The results indicate that that the majority of the
respondents did not have a negative perception towards the electronic billboard
regarding distraction and traffic safety. These results also indicate that a large portion
of the driving public (one-third) may find this electronic billboard to be a safety
concern, even though an analysis of crash data shows a reduction in collision.
37
Figure 9: Respondents’ Opinion on Distraction
Figure 10: Respondents’ Opinion on Safety Risk
38
Chapter 7
CONCLUSIONS AND RECOMMENDATIONS
The presence of the electronic billboard near Sacramento State does not
appear to have a significant negative impact in traffic performance (flow, speed, and
lane occupancy) or incidents in the study section of the freeway. Because many of
the road users at this segment are probably commuters, they may be familiar with the
electronic billboard, and it does not appear to affect their driving. Even though
electronic billboards are capable of displaying multiple messages/commercials at
different times, the advertisements do not appear to be a major distraction to drivers
at this location. No changes in measurable impact on road safety after the installation
of the electronic billboard were observed. At the same time, a public opinion survey
indicated that more than two-thirds of self-identified drivers through the study area
who were surveyed believed that this electronic billboard does not pose a safety risk
to traffic.
Limitations
It is recognized that this study has many limitations. The period was of two
months before and after the installation of electronic billboard considered in the
study of traffic performance (flow, speed, and lane occupancy). Analysis of longer
periods of time before and after the installation of the electronic billboard could
yield more reliable results. At the same time, this study primarily focused on
39
morning and afternoon peak periods on Wednesdays. A broader study could include
more electronic billboards and the analysis of traffic on more days and more times.
Also, drivers involved in an incident may not want to say whether the
incident occurred as a result of the electronic billboard. As a result, positively
identifying driver distraction because of the electronic billboard can be difficult. The
PeMS database only provides information based on injury or non-injury incidents.
The data from the campus opinion survey was limited to a two-day random
sample of the campus population, which may be a different demographic group
(gender, age, employment status, and income) of travelers on the study segment on
Highway 50. Including a more representative sample of the segment population may
provide more results relevant to the users of this freeway.
Overall, based on this narrowly-scoped project, we cannot make
generalizations or conclusions about the safety of all electronic billboards next to
highways. Different locations may have different roadway characteristics and
different travel patterns, and drivers may react differently in other locations.
Future Research
There are few other factors affecting the traffic performance on the study
segments. The impact of gasoline prices, economic downturn, weather, and ban on
cell-phone use during driving may have some effect on traffic performance and on
traffic safety. Similarly, the number or density of electronic billboards in a particular
section, the types of advertisement, the types of road users (gender, age, employment
40
status, and income), and the travel patterns in different location are other factors to
consider for study. Because these factors also affect traffic performance and safety, it
would be useful to take these factors into account when determining their relative
importance to the presence of an electronic billboard. Altogether, the results would
be able to more definitively identify if there is an impact of electronic billboard on
traffic performance and safety. Further, the similar studies in different locations
would be helpful to better generalize the safety impacts of electronic billboards on
state highways.
41
APPENDIX A
FHWA Guidance on Off-Premise Message Sign (Source: OAAA, 2009)
42
43
44
45
APPENDIX B
46
47
APPENDIX C
Figure 11: October 2007 Eastbound Traffic
48
Figure 12: November 2007 Eastbound Traffic
49
Figure 13: October 2007 Westbound Traffic
50
Figure 14: November 2007 Westbound Traffic
51
Figure 15: October 2008 Eastbound Traffic
52
Figure 16: November 2008 Eastbound Traffic
53
Figure 17: October 2008 Westbound Traffic
54
Figure 18: November 2008 Westbound Traffic
55
Figure 19: Oct - Nov 2007 Eastbound Relationship Among Basic Parameters
56
Figure 20: Oct - Nov 2008 Eastbound Relationship Among Basic Parameters
57
Figure 21: Oct - Nov 2007 Westbound Relationship Among Basic Parameters
58
Figure 22: Oct - Nov 2008 Westbound Relationship Among Basic Parameters
59
Figure 23: Comparison of Eastbound Traffic (Wednesdays October to November)
60
Figure 24: Comparison of Westbound Traffic (Wednesdays October to November)
61
APPENDIX D
Table 4: Eastbound Incident Data- Aug. 2007 to July 2008
(Source: PeMS)
#
343
Start
8/22/2007
7:48
Duration
(mins)
18
Abs
Postmile
8.1
Location
EB US50 AT
65TH ST
Description
1182 - Collision Non Injury
1316
10/31/2007
17:02
0
8.1
65TH ST AT
EB US50
1182 - Collision Non Injury
1963
11/1/2007
23:49
2
8.1
65TH ST AT
EB US50
20002 - Hit & Run No Injuries
817
12/31/2007
14:01
47
8.1
65TH ST AT
EB US50
20002 - Hit & Run No Injuries
953
1/17/2008
15:36
3
8.1
EB US50 ON
65TH ST
OFR
1183H - Collision Blocking Lane - No
Details
1554
1/17/2008
20:50
0
8.1
EB US50 ON
65TH ST
OFR
1183H - Collision Blocking Lane - No
Details
1691
2/14/2008
22:06
59
8.1
EB US50 AT
65TH ST
1182 - Collision Non Injury
608
3/5/2008
11:49
35
8.1
65TH ST
ONR TO EB
US50
1183 - Collision - No
Further Details
624
7/14/2008
10:34
6
8.1
65TH ST
ONR TO EB
US50
1183 - Collision - No
Further Details
534
7/19/2008
9:24
10
8.1
65TH ST
ONR TO EB
US50
1179 - Collision Ambulance
Responding
1196
8/17/2007
15:23
31
8.3
EB US50 JEO
65TH ST
1182 - Collision Non Injury
309
9/18/2007
7:59
21
8.3
EB US50 JEO
65TH ST
1183H - Collision Blocking Lane - No
Details
276
1/31/2008
7:41
2
8.3
EB US50 JEO
65TH ST
1182 - Collision Non Injury
62
2/9/2008
20:35
34
8.3
EB US50 JEO
65TH ST
1183 - Collision - No
Further Details
2/11/2008
8:14
81
8.3
EB US50 JEO
65TH ST
1183H - Collision Blocking Lane - No
Details
1883
3/1/2008
22:47
1
8.3
EB US50 JEO
65TH ST
1179H - Collision Ambulance Blocking Lane
1524
4/18/2008
18:02
6
8.3
EB US50 JEO
65TH ST
1182 - Collision Non Injury
1900
5/26/2008
22:25
28
8.3
EB US50 JEO
65TH ST
1183 - Collision - No
Further Details
624
5/29/2008
11:50
26
8.3
EB US50 JEO
65TH ST
1182 - Collision Non Injury
7/2/2008
21:59
0
8.3
EB US50 JEO
65TH ST
1182 - Collision Non Injury
9/15/2007
6:05
51
8.83
EB US50
JWO HOWE
AV
1183 - Collision - No
Further Details
10/18/2007
17:30
1
8.83
EB US50
JWO HOWE
AV
1183 - Collision - No
Further Details
2/11/2008
8:15
0
8.83
EB US50
JWO HOWE
AV
1183H - Collision Blocking Lane - No
Details
1592
335
1911
336
1170
337
63
Table 5: Eastbound Incident Data- Aug. 2008 to July 2009
(Source: PeMS)
#
948
Start
8/16/2008
13:42
Duration
(mins)
1
Abs
Postmile
8.1
Location
EB US50 AT
65TH ST
Description
1182 - Collision Non Injury
9/5/2008
20:02
13
8.1
EB US50 AT
65TH ST
1182 - Collision Non Injury
887
10/17/2008
14:23
5
8.1
EB US50 AT
65TH ST
1183 - Collision - No
Further Details
186
11/8/2008
2:15
11
8.1
EB US50 AT
65TH ST
1183 - Collision - No
Further Details
1295
11/20/2008
17:42
39
8.1
EB US50 AT
65TH ST
1182H - Collision Non Injury - Blocking
Lane
405
11/26/2008
10:07
34
8.1
EB US50 AT
65TH ST
1183 - Collision - No
Further Details
300
11/27/2008
8:31
1
8.1
EB US50 AT
65TH ST
20002 - Hit & Run No Injuries
241
12/12/2008
6:47
148
8.1
EB US50 AT
65TH ST
1182 - Collision Non Injury
394
12/21/2008
7:55
70
8.1
EB US50 AT
65TH ST
1182H - Collision Non Injury - Blocking
Lane
700
12/27/2008
12:29
1
8.1
EB US50 AT
65TH ST
1183H - Collision Blocking Lane - No
Details
526
1/6/2009
11:15
0
8.1
65TH ST AT
EB US50
1183 - Collision - No
Further Details
1557
1/7/2009
21:19
2
8.1
65TH ST JSO
EB US50
20002 - Hit & Run No Injuries
1209
2/6/2009
15:14
0
8.1
EB US50 AT
65TH ST
1182H - Collision Non Injury - Blocking
Lane
2/18/2009
8:20
20
8.1
65TH ST
ONR TO EB
US50
20002 - Hit & Run No Injuries
1791
399
64
911
3/11/2009
13:22
1
8.1
EB US50 ON
65TH ST OFR
1182 - Collision Non Injury
1669
3/13/2009
18:11
54
8.1
EB US50 AT
65TH ST
1182 - Collision Non Injury
343
3/23/2009
7:53
34
8.1
EB US50 AT
65TH ST
1179 - Collision Ambulance
Responding
986
3/28/2009
13:00
102
8.1
EB US50 AT
65TH ST
1179 - Collision Ambulance
Responding
1971
4/7/2009
21:28
19
8.1
65TH ST
ONR TO EB
US50
1179 - Collision Ambulance
Responding
961
5/2/2009
13:13
17
8.1
EB US50 AT
65TH ST
1183H - Collision Blocking Lane - No
Details
747
5/10/2009
11:03
13
8.1
EB US50 AT
65TH ST
1179H - Collision Ambulance Blocking Lane
1527
5/22/2009
16:13
51
8.1
EB US50 AT
65TH ST
1182 - Collision Non Injury
1423
6/8/2009
16:34
74
8.1
EB US50 AT
65TH ST
1179H - Collision Ambulance Blocking Lane
2228
6/14/2009
22:31
27
8.1
EB US50 ON
65TH ST OFR
1183H - Collision Blocking Lane - No
Details
1619
6/23/2009
17:40
0
8.1
EB US50 AT
65TH ST
20002 - Hit & Run No Injuries
1379
7/10/2009
15:43
5
8.1
EB US50 ON
65TH ST OFR
1182 - Collision Non Injury
9/3/2008 8:32
1
8.3
EB US50 JEO
65TH ST
1182 - Collision Non Injury
1358
10/15/2008
17:54
0
8.3
EB US50 JEO
65TH ST
1183H - Collision Blocking Lane - No
Details
1157
10/18/2008
16:22
3
8.3
EB US50 JEO
65TH ST
20002 - Hit & Run No Injuries
3/3/2009 9:58
0
8.3
EB US50 JEO
65TH ST
1182 - Collision Non Injury
3/10/2009
16:54
13
8.3
EB US50 JEO
65TH ST
1183H - Collision Blocking Lane - No
Details
389
559
1384
65
1579
6/23/2009
17:25
4
8.3
EB US50 JEO
65TH ST
1183 - Collision - No
Further Details
2008
7/17/2009
18:47
0
8.3
EB US50 JEO
65TH ST
1183 - Collision - No
Further Details
1659
8/2/2008
19:29
0
8.83
EB US50
JWO HOWE
AV
1179 - Collision Ambulance
Responding
9/9/2008 8:51
2
8.83
EB US50
JWO HOWE
AV
1182 - Collision Non Injury
10/15/2008
17:54
0
8.83
EB US50
JWO HOWE
AV
1183 - Collision - No
Further Details
3/3/2009 9:57
1
8.83
EB US50
JWO HOWE
AV
1182 - Collision Non Injury
1179
4/16/2009
15:05
5
8.83
EB US50
JWO HOWE
AV
1183H - Collision Blocking Lane - No
Details
1572
6/23/2009
17:23
12
8.83
EB US50
JWO HOWE
AV
1182H - Collision Non Injury - Blocking
Lane
7/4/2009 9:13
24
8.83
EB US50
JWO HOWE
AV
1183 - Collision - No
Further Details
405
1356
555
657
66
Table 6: Westbound Incident Data- Aug. 2007 to July 2008
(Source: PeMS)
#
Duration
(mins)
0
754
Start
7/27/2008
12:54
987
7/25/2008
14:40
0
1331
7/22/2008
18:07
Abs
Postmile
8.66
Location
WB US50
JEO 65TH ST
Description
1183H - Collision Blocking Lane -
8.66
WB US50
JWO STATE
COLLEGE
1182 - Collision Non Injury
33
8.66
WB US50
JEO 65TH ST
1179H - Collision Ambulance Blocking Lane
7/1/2008 8:04
1
8.66
WB US50
JEO 65TH ST
1182H - Collision Non Injury Blocking Lane
1731
6/11/2008
19:44
1
8.66
WB US50
JEO 65TH ST
1182 - Collision Non Injury
1120
5/2/2008
15:34
1
8.66
WB US50
JEO 65TH ST
1183H - Collision Blocking Lane - No
Details
354
4/30/2008
8:39
13
8.66
WB US50
JWO STATE
COLLEGE
1182H - Collision Non Injury Blocking Lane
152
4/21/2008
5:16
46
8.66
WB US50
JEO 65TH ST
1179H - Collision Ambulance Blocking Lane
1428
4/9/2008
18:11
0
8.66
WB US50
JEO 65TH ST
1183 - Collision No Further Details
1230
4/8/2008
17:41
7
8.66
WB US50
JEO 65TH ST
1183H - Collision Blocking Lane - No
Details
1016
3/27/2008
16:09
0
8.66
WB US50
JEO 65TH ST
1183 - Collision No Further Details
1012
3/27/2008
16:08
55
8.66
WB US50
JEO 65TH ST
1183 - Collision No Further Details
279
3/20/2008
7:25
13
8.66
WB US50
JEO 65TH ST
1183 - Collision No Further Details
355
67
3/4/2008 8:09
1
8.66
WB US50
JEO 65TH ST
1182 - Collision Non Injury
2/15/2008
16:09
1
8.66
WB US50
JEO 65TH ST
20002 - Hit & Run
- No Injuries
2/8/2008
11:48
1
8.66
WB US50
JEO 65TH ST
1182H - Collision Non Injury Blocking Lane
7/10/2008
0:58
4
8.86
WB US50
JWO HOWE
AV
1183H - Collision Blocking Lane - No
Details
1324
2/7/2008
17:46
10
8.86
WB US50
JWO HOWE
AV
1179 - Collision Ambulance
Responding
1053
1/3/2008
15:31
4
8.86
WB US50
JWO HOWE
AV
1182 - Collision Non Injury
1278
12/3/2007
16:50
34
8.86
WB US50
JWO HOWE
AV
1183 - Collision No Further Details
1353
11/28/2007
18:27
5
8.86
WB US50
JWO HOWE
AV
1183 - Collision No Further Details
898
11/10/2007
13:22
4
8.86
WB US50
JWO HOWE
AV
1183H - Collision Blocking Lane - No
Details
1348
10/23/2007
18:11
49
8.86
WB US50
JWO HOWE
AV
1183H - Collision Blocking Lane - No
Details
522
10/16/2007
10:28
0
8.86
WB US50
JWO HOWE
AV
1183 - Collision No Further Details
450
8/16/2007
8:40
82
8.86
WB US50
JWO HOWE
AV
1183 - Collision No Further Details
1093
5/19/2008
15:13
3
9.06
WB US50 AT
HOWE AV
1182 - Collision Non Injury
5/9/2008
11:20
9
9.06
HOWE AV
ONR TO WB
US50
1183 - Collision No Further Details
1257
4/29/2008
16:45
115
9.06
WB US50 AT
HOWE AV
1182 - Collision Non Injury
597
3/14/2008
12:19
49
9.06
WB US50 ON
HOWE AV
OFR
20002 - Hit & Run
- No Injuries
269
1/28/2008
7:09
5
9.06
WB US50 ON
HOWE AV
OFR
1182H - Collision Non Injury Blocking Lane
289
1212
636
88
622
68
12/23/2007
12:23
11
9.06
WB US50 ON
HOWE AV
OFR
1182H - Collision Non Injury Blocking Lane
12/3/2007
17:13
0
9.06
HOWE AV
ONR TO WB
US50
1183 - Collision No Further Details
512
10/30/2007
10:09
0
9.06
HOWE AV
ONR TO WB
US50
1179 - Collision Ambulance
Responding
509
10/30/2007
10:07
137
9.06
WB US50 ON
HOWE AV
OFR
1179 - Collision Ambulance
Responding
1245
10/2/2007
17:19
0
9.06
HOWE AV
ONR TO WB
US50
1179 - Collision Ambulance
Responding
1244
10/2/2007
17:18
2
9.06
HOWE AV
ONR TO WB
US50
1179H - Collision Ambulance Blocking Lane
1448
9/24/2007
17:47
28
9.06
WB US50 AT
HOWE AV
1183H - Collision Blocking Lane - No
Details
335
9/24/2007
7:37
21
9.06
WB US50 ON
HOWE AV
OFR
1182 - Collision Non Injury
1377
9/21/2007
17:01
16
9.06
WB US50 ON
HOWE AV
OFR
1183 - Collision No Further Details
1103
9/17/2007
15:39
30
9.06
WB US50 ON
HOWE AV
OFR
1179H - Collision Ambulance Blocking Lane
9/7/2007
10:09
4
9.06
HOWE AV
ONR TO WB
US50
1183 - Collision No Further Details
35
8/5/2007 0:16
57
9.26
WB US50
JEO HOWE
AV
1179 - Collision Ambulance
Responding
93
8/23/2007
1:33
4
9.26
WB US50
JEO HOWE
AV
1183 - Collision No Further Details
1257
8/23/2007
15:56
99
9.26
WB US50
JEO HOWE
AV
1183 - Collision No Further Details
1285
8/23/2007
16:09
28
9.26
WB US50
JEO HOWE
AV
1183 - Collision No Further Details
215
10/9/2007
6:40
1
9.26
WB US50
JEO HOWE
AV
1183 - Collision No Further Details
10/18/2007
17:52
3
9.26
WB US50
JEO HOWE
AV
1183 - Collision No Further Details
801
1331
532
1226
69
1338
10/25/2007
17:48
18
9.26
WB US50
JEO HOWE
AV
1182H - Collision Non Injury Blocking Lane
2032
12/6/2007
21:57
9
9.26
WB US50
JEO HOWE
AV
1183H - Collision Blocking Lane - No
Details
1498
12/7/2007
17:30
8
9.26
WB US50
JEO HOWE
AV
1182H - Collision Non Injury Blocking Lane
1454
1/22/2008
18:08
1
9.26
WB US50
JEO HOWE
AV
1182 - Collision Non Injury
1854
3/12/2008
23:14
1
9.26
WB US50
JEO HOWE
AV
1179 - Collision Ambulance
Responding
1553
3/15/2008
18:58
42
9.26
WB US50
JEO HOWE
AV
1182H - Collision Non Injury Blocking Lane
494
4/18/2008
9:43
288
9.26
WB US50
JEO HOWE
AV
1179H - Collision Ambulance Blocking Lane
1434
5/21/2008
16:53
19
9.26
WB US50
JEO HOWE
AV
1182 - Collision Non Injury
674
5/31/2008
11:39
16
9.26
WB US50
JEO HOWE
AV
1179 - Collision Ambulance
Responding
333
6/7/2008 5:29
28
9.26
WB US50
JEO HOWE
AV
1183 - Collision No Further Details
348
7/18/2008
7:32
21
9.26
WB US50
JEO HOWE
AV
20002 - Hit & Run
- No Injuries
743
7/27/2008
12:47
33
9.26
WB US50
JEO HOWE
AV
1179 - Collision Ambulance
Responding
70
Table 7: Westbound Incident Data- Aug. 2008 to July 2009
(Source: PeMS)
#
606
Start
8/19/2008
12:33
Duration
(mins)
15
Abs
Postmile
8.66
Location
WB US50
JEO 65TH
ST
Description
1182 - Collision Non Injury
1117
8/22/2008
15:32
0
8.66
WB US50
JEO 65TH
ST
1182H - Collision Non Injury Blocking Lane
1074
9/4/2008 15:38
0
8.66
WB US50
JEO 65TH
ST
1183 - Collision No Further Details
989
9/10/2008
15:42
2
8.66
WB US50
JEO 65TH
ST
20002 - Hit & Run
- No Injuries
1431
9/24/2008
17:45
13
8.66
WB US50
JEO 65TH
ST
1182H - Collision Non Injury Blocking Lane
1205
10/17/2008
16:33
0
8.66
WB US50
JEO 65TH
ST
1183 - Collision No Further Details
1218
10/17/2008
16:38
7
8.66
WB US50
JEO 65TH
ST
1182 - Collision Non Injury
364
10/21/2008
9:01
7
8.66
WB US50
JEO 65TH
ST
1182 - Collision Non Injury
1413
10/23/2008
17:45
11
8.66
WB US50
JEO 65TH
ST
1179 - Collision Ambulance
Responding
1377
11/5/2008
17:55
0
8.66
WB US50
JEO 65TH
ST
1183H - Collision Blocking Lane - No
Details
1056
11/10/2008
15:56
41
8.66
WB US50
JEO 65TH
ST
1182H - Collision Non Injury Blocking Lane
1168
11/21/2008
16:12
12
8.66
WB US50
JEO 65TH
ST
1183H - Collision Blocking Lane - No
Details
1394
11/26/2008
18:04
0
8.66
WB US50
JEO 65TH
ST
1183H - Collision Blocking Lane - No
Details
1016
12/5/2008
15:29
2
8.66
WB US50
JEO 65TH
ST
1183 - Collision No Further Details
71
1256
12/6/2008
17:18
34
8.66
WB US50
JEO 65TH
ST
1183 - Collision No Further Details
1522
12/22/2008
17:40
0
8.66
WB US50
JEO 65TH
ST
1182H - Collision Non Injury Blocking Lane
924
12/29/2008
14:21
60
8.66
WB US50
JEO 65TH
ST
1179 - Collision Ambulance
Responding
1771
1/1/2009 19:05
47
8.66
WB US50
JEO 65TH
ST
20002 - Hit & Run
- No Injuries
1443
1/14/2009
17:19
51
8.66
WB US50
JEO 65TH
ST
1179H - Collision Ambulance Blocking Lane
1616
1/29/2009
18:30
32
8.66
WB US50
JEO 65TH
ST
1182H - Collision Non Injury Blocking Lane
815
2/24/2009
12:31
0
8.66
WB US50
JEO 65TH
ST
1182 - Collision Non Injury
449
3/1/2009 7:27
23
8.66
WB US50
JEO 65TH
ST
1183 - Collision No Further Details
254
3/11/2009 7:07
50
8.66
WB US50
JEO 65TH
ST
1183H - Collision Blocking Lane - No
Details
1543
4/7/2009 18:08
32
8.66
WB US50
JWO STATE
COLLEGE
1183H - Collision Blocking Lane - No
Details
1709
4/7/2009 19:16
20
8.66
WB US50
JEO 65TH
ST
1183H - Collision Blocking Lane - No
Details
1388
4/23/2009
16:12
40
8.66
WB US50
JEO 65TH
ST
1183H - Collision Blocking Lane - No
Details
5/6/2009 9:46
27
8.66
WB US50
JEO 65TH
ST
1182 - Collision Non Injury
6/4/2009 16:43
0
8.66
WB US50
JEO 65TH
ST
20002 - Hit & Run
- No Injuries
823
6/17/2009
13:13
20
8.66
WB US50
JEO 65TH
ST
1182 - Collision Non Injury
1190
6/18/2009
15:15
53
8.66
WB US50
JEO 65TH
ST
20002 - Hit & Run
- No Injuries
7/1/2009 5:59
14
8.66
WB US50
JEO 65TH
ST
1179H - Collision Ambulance Blocking Lane
564
1497
261
72
528
7/7/2009 9:48
17
8.66
WB US50
JEO 65TH
ST
1182 - Collision Non Injury
536
7/10/2009 9:44
35
8.66
WB US50
JEO 65TH
ST
1183 - Collision No Further Details
505
7/21/2009 8:59
2
8.66
WB US50
JEO 65TH
ST
1183 - Collision No Further Details
1421
7/30/2009
16:26
42
8.66
WB US50
JEO 65TH
ST
1183H - Collision Blocking Lane - No
Details
1070
9/4/2008 15:37
50
8.86
WB US50
JWO HOWE
AV
1183 - Collision No Further Details
1370
10/23/2008
17:28
14
8.86
WB US50
JWO HOWE
AV
1182 - Collision Non Injury
1126
10/26/2008
17:07
123
8.86
WB US50
JWO HOWE
AV
1179 - Collision Ambulance
Responding
1665
1/30/2009
18:01
1
8.86
WB US50
JWO HOWE
AV
1182 - Collision Non Injury
1453
3/3/2009 16:22
90
8.86
WB US50
JWO HOWE
AV
1183H - Collision Blocking Lane - No
Details
1374
3/10/2009
16:53
0
8.86
WB US50
JWO HOWE
AV
1182 - Collision Non Injury
1253
4/24/2009
15:14
1
8.86
WB US50
JWO HOWE
AV
1182 - Collision Non Injury
1301
9/28/2008
16:54
0
9.06
WB US50
ON HOWE
AV OFR
1182 - Collision Non Injury
1358
10/7/2008
17:32
0
9.06
WB US50
AT HOWE
AV
1182 - Collision Non Injury
1277
10/23/2008
16:46
32
9.06
HOWE AV
ONR TO
WB US50
20002 - Hit & Run
- No Injuries
343
11/20/2008
8:46
19
9.06
HOWE AV
ONR TO
WB US50
1183 - Collision No Further Details
1006
11/26/2008
15:19
18
9.06
WB US50
ON HOWE
AV OFR
1182H - Collision Non Injury Blocking Lane
12/5/2008
15:03
50
9.06
HOWE AV
ONR TO
WB US50
1182 - Collision Non Injury
957
73
998
12/9/2008
16:03
119
9.06
WB US50
ON HOWE
AV OFR
1183H - Collision Blocking Lane - No
Details
909
12/21/2008
14:18
33
9.06
WB US50
AT HOWE
AV
1182H - Collision Non Injury Blocking Lane
931
12/29/2008
14:23
0
9.06
WB US50
AT HOWE
AV
1183 - Collision No Further Details
1/2/2009 18:00
33
9.06
HOWE AV
ONR TO
WB US50
1182H - Collision Non Injury Blocking Lane
1/4/2009 1:49
28
9.06
HOWE AV
ONR TO
WB US50
1179 - Collision Ambulance
Responding
1510
1/14/2009
17:45
59
9.06
WB US50
ON HOWE
AV OFR
1182H - Collision Non Injury Blocking Lane
1193
1/19/2009
15:29
14
9.06
WB US50
ON HOWE
AV OFR
1182 - Collision Non Injury
2/9/2009 7:25
42
9.06
WB US50
ON HOWE
AV OFR
1182 - Collision Non Injury
1344
2/13/2009
14:57
29
9.06
WB US50
ON HOWE
AV OFR
1182 - Collision Non Injury
841
2/15/2009
12:43
9
9.06
WB US50
ON HOWE
AV OFR
1182 - Collision Non Injury
1521
2/22/2009
18:07
17
9.06
HOWE AV
ONR TO
WB US50
1183 - Collision No Further Details
1483
2/25/2009
16:39
8
9.06
WB US50
AT HOWE
AV
1183 - Collision No Further Details
1174
4/7/2009 15:47
23
9.06
HOWE AV
JNO WB
US50
20002 - Hit & Run
- No Injuries
1672
6/4/2009 17:49
38
9.06
WB US50
ON HOWE
AV OFR
1182H - Collision Non Injury Blocking Lane
319
6/17/2009 7:34
24
9.06
WB US50
ON HOWE
AV OFR
1182 - Collision Non Injury
1367
9/3/2008 17:24
20
9.26
WB US50
JEO HOWE
AV
1179H - Collision Ambulance Blocking Lane
1217
9/11/2008
17:03
2
9.26
WB US50
JEO HOWE
AV
1182H - Collision Non Injury Blocking Lane
1414
147
307
74
9/26/2008
17:27
2
9.26
WB US50
JEO HOWE
AV
20002 - Hit & Run
- No Injuries
10/16/2008
8:01
24
9.26
WB US50
JEO HOWE
AV
1182 - Collision Non Injury
1283
11/1/2008
16:25
36
9.26
WB US50
JEO HOWE
AV
1182 - Collision Non Injury
527
11/4/2008
10:15
3
9.26
WB US50
JEO HOWE
AV
1183 - Collision No Further Details
647
11/26/2008
12:44
34
9.26
WB US50
JEO HOWE
AV
1183H - Collision Blocking Lane - No
Details
322
12/15/2008
7:38
16
9.26
WB US50
JEO HOWE
AV
1183 - Collision No Further Details
1207
12/16/2008
16:50
34
9.26
WB US50
JEO HOWE
AV
1183 - Collision No Further Details
1816
1/23/2009
18:30
0
9.26
WB US50
JEO HOWE
AV
1183 - Collision No Further Details
1451
1/27/2009
17:47
30
9.26
WB US50
JEO HOWE
AV
1182 - Collision Non Injury
1258
2/2/2009 15:25
10
9.26
WB US50
JEO HOWE
AV
1183 - Collision No Further Details
361
2/3/2009 8:31
54
9.26
WB US50
JEO HOWE
AV
20002 - Hit & Run
- No Injuries
765
2/21/2009
11:40
61
9.26
WB US50
JEO HOWE
AV
1182H - Collision Non Injury Blocking Lane
583
2/25/2009
10:10
14
9.26
WB US50
JEO HOWE
AV
1179H - Collision Ambulance Blocking Lane
1406
3/3/2009 16:09
3
9.26
WB US50
JEO HOWE
AV
1182H - Collision Non Injury Blocking Lane
1422
3/3/2009 16:13
146
9.26
WB US50
JEO HOWE
AV
1182H - Collision Non Injury Blocking Lane
1432
3/3/2009 16:16
14
9.26
WB US50
JEO HOWE
AV
1182 - Collision Non Injury
1749
3/3/2009 18:20
53
9.26
WB US50
JEO HOWE
AV
1179 - Collision Ambulance
Responding
1435
275
75
4/28/2009 7:04
0
9.26
WB US50
JEO HOWE
AV
20002 - Hit & Run
- No Injuries
4/30/2009
16:26
43
9.26
WB US50
JEO HOWE
AV
1182H - Collision Non Injury Blocking Lane
5/7/2009 9:02
29
9.26
WB US50
JEO HOWE
AV
1182 - Collision Non Injury
2259
6/28/2009
21:45
20
9.26
WB US50
JEO HOWE
AV
1183H - Collision Blocking Lane - No
Details
1007
7/26/2009
12:38
10
9.26
WB US50
JEO HOWE
AV
1183H - Collision Blocking Lane - No
Details
462
7/28/2009 8:50
18
9.26
WB US50
JEO HOWE
AV
1182 - Collision Non Injury
467
7/28/2009 8:51
46
9.26
WB US50
JEO HOWE
AV
1183 - Collision No Further Details
212
1278
361
76
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