Intelligent Transportation Systems

San Francisco PedSafe II Project Outcomes and Lessons Learned

Hua, Jenna
Gutierrez, Nicolas
Banerjee, Ipsita
Markowitz, Frank
Ragland, David R
2009

This paper presents the project outcomes and lessons learned from the San Francisco PedSafe, a comprehensive pedestrian safety planning and engineering project funded by the Federal Highway Administration. It assesses the effectiveness of the Phase I pedestrian safety plan targeted to higher-injury areas by evaluating the Phase II implementation of a range of mostly low-to-moderate-cost innovative safety improvements.A total of 13 countermeasures (comprised of nine general engineering countermeasures and four Intelligent Transportation Systems (ITS) countermeasures) were implemented by the...

Impact of Pedestrian Presence on Movement of Left-Turning Vehicles: Method, Preliminary Results & Possible Use in Intersection Decision Support

Banerjee, Ipsita
Shladover, Steven E
Misener, James A
Chan, Ching-Yao
Ragland, David R
2004

Warning systems are being developed for left-turning vehicles at intersections where protected left-turns are not warranted or cannot be provided, based on limitations of right of way or intersection capacity. These are meant to provide warnings to left-turning vehicles of vehicles approaching from the opposite direction, when the time to turn may be deemed unsafe. To implement these warning systems, it is necessary to estimate in near real time, the probability of conflict between the two approaching vehicles. A study is being conducted with the help of video and radar at various...

Evaluation of the Accuracy of Global Positioning System Coordinates for Collision Locations in California

Bingham, John
Strang, Garrett
Oum, Sang Hyouk
2014

Traffic collision reports typically provide descriptive locations indicating where a collision occurred and referencing the nearest intersection. Global Positioning System (GPS) technology can be used to provide latitude and longitude coordinates in addition to the descriptive location and many states now include GPS coordinates in collision reports. However, research has shown that there is potential for numerous errors when police agencies use GPS to complete traffic collision reports. In California, GPS coordinates have been included in the statewide collision database since 2006, but...

A Review of ITS-Based Pedestrian Injury Countermeasures

Bechtel, Allyson K
Geyer, Judy
Ragland, David R
2003

Crashes between motor vehicles and pedestrians caused at least 4,882 deaths and about 78,000 injuries in 2001 in the United States. In recognition of these troubling statistics, many public and private institutions look to Intelligent Transportation Systems (ITS) technologies. Few resources are available to provide a comprehensive summary of the effectiveness of these options. This report reviews previous scientific evaluation of red light enforcement cameras, illuminated walk signal push buttons, automated pedestrian detection systems for traffic signals, flashing crosswalk lights,...

A Database for Active Transportation Infrastructure and Volume

Proulx, Frank R.
Zhang, Yuanyuan, PhD
Grembek, Offer, PhD
2014

Information about pedestrian infrastructure and volume is indispensable to monitoring, evaluating, and improving the environment for comfortable and safe walking. However, determining and organizing the various types of data in a way that is easy to update and analyze can present challenges. This study designed and developed a relational database for pedestrian infrastructure and volume, and comprises two core components (node table and approach table) and several sub-components (tables for crosswalks, sidewalks, buffers, signs, transits, bikeways, bicycle parking, and volumes). Important...

An Intensive Pedestrian Safety Engineering Study Using Computerized Crash Analysis

Ragland, David R
Markowitz, Frank
MacLeod, Kara E
2003

Over the past year, the San Francisco Department of Parking and Traffic (DPT) conducted an intensive pedestrian-safety engineering study, the PedSafe Study. PedSafe was funded by the Federal Highway Administration (FHWA)*, which also funded companion studies in Las Vegas and Miami. The study was designed to analyze pedestrian injuries by zones (i.e., neighborhoods or districts) and to identify those most amenable to prevention efforts. The DPT expects to utilize the methodology and information from the PedSafe study to help shape a citywide pedestrian master plan. This paper describes the...

Gap acceptance for vehicles turning left across on-coming traffic: Implications for Intersection Decision Support design

Ragland, David R
Arroyo, Sofia
Shladover, Steven E.
Misener, James A.
Chan, Ching-Yao
2006

A left-turning vehicle (Subject Vehicle, SV) attempting to cross the path of an oncoming vehicle (Principal Other Vehicle, POV) at an intersection typically does not have the right of way. The main task of the SV driver is to find an adequate opportunity in opposing traffic to initiate the left-turn maneuver. To reduce the probability of a conflict, warning systems, such as Intersection Decision Support (IDS) systems, are being developed. These systems alert drivers of SV vehicles attempting to negotiate a left turn about traffic approaching from the opposite direction. The current paper (...

Exploring the Future of Integrated Transportation Systems in the United States from 2030 to 2050: Application of a Scenario Planning Tool

Shaheen, Susan, PhD
Camel, Madonna
Lee, Kunik
2013

Intelligent transportation systems (ITS) have primarily focused on systems management. To further improve connectivity and safety in the future, ITS might embrace a more holistic planning approach. While the future of ITS remains an open question, its evolution is closely linked to how the world evolves on many dimensions, social, political, economic, legal, and environmental. In this paper, the authors present results from four expert workshops. These consisted of an initial steering committee workshop (February 2011), two expert scenario-planning workshops (June 2011), and a final...

Smartphone Applications to Influence Travel Choices: Practices and Policies

Shaheen, Susan
Cohen, Adam
Zohdy, Ismail
Kock, Beaudry
2016

This primer provides an overview of current practices in this emerging field and looks toward the future in the evolution and development of smartphone applications for the transportation sector. The primer provides an introduction and overview smartphone applications (known as “apps”); discusses the background, evolution, and development of smartphone apps; reviews the types of smartphone applications promoting transportation efficiency and congestion reduction; discusses transportation apps and their impacts on traveler behavior; examines current challenges; and concludes with guiding...

Innovative Mobility Services & Technologies: A Pathway Towards Transit Flexibility, Convenience, and Choice

Shaheen, Susan A.
2012

The number of senior citizens is expected to double by the year 2020, representing 18% of the nation’s population. After age 75, driving performance begins to decline due to changes in health and medication effects. Indeed, one quarter of seniors over 75 are expected to require alternative transportation services in the future. This chapter examines transit and innovative mobility options to better meet the needs of the growing older population in the near (2011) and more distant (2021) future. Barriers to transit use among older adults include anxiety and confusion about using transit;...