Road User Behavior

High Visibility Enforcement Programs: California’s State and University Traffic Safety Partnership

Cooper, Jill F.
Kan, Irene
Cadet, Akilah
Rauch, Sharleen
Murphy, Christopher J.
2009

Traffic collisions are a leading cause of death and injury in California and the number one cause of death for people between the ages of one and 44. High-visibility enforcement programs (HVEs) are administered nationwide by the National Highway Traffic Safety Administration, and combine intensive enforcement of a particular traffic safety law with widespread media and public education campaigns. HVE programs have been shown to be effective in reducing alcohol-impaired driving and promoting seat belt use. A major challenge in implementing HVEs, however, exists among local police...

Analysis of Wet Weather Related Collision Concentration Locations: Empirical Assessment of Continuous Risk Profile

Oh, Soonmi
Chung, Koohong
Ragland, David R.
Chan, Ching-Yao
2009

The objective of the study described in this paper is to identify common site features that may contribute to high collision rates under wet pavement conditions. To minimize falsely identified high collision concentration locations (HCCL) in evaluating factors contributing to high collision rate, this study accessed the magnitude of false positives (i.e., identifying sites for safety improvements that should not have been selected) by comparing HCCLs identified by the existing conventional sliding moving window approach with the ones identified by the Continuous Risk Profile (CRP)...

Evaluation of an Urban Travel Training for Older Adults

Babka, Rhianna JoIris
Cooper, Jill F.
Ragland, David R.
2009

The size of the aging population in the United States is increasing, and transportation is critical to maintaining older adults mobility, independence, and quality of life. Travel training programs designed to increase individual knowledge are one way to encourage older adult use of fixed- route transit and improve the transportation options for older adults. The analysis conducted in this paper explores characteristics of travel-training participants in Alameda County, California in 2007-2008 and their knowledge and concerns regarding public transit. Specific issues addressed...

A Methodology of Quantifying Precipitation Exposure for Wet-Weather Collisions and Evaluating Effectiveness of Open-Grade Asphalt Concrete as a CountermeasureWeather-related crashes represent a significant concern in roadway safety.

Chan, Ching-Yao
Jin, Eui-Jae
Oh, Soon Mi
Ragland, David R.
2010

Weather-related crashes represent a significant concern in roadway safety. Wet collisions often resulted in injuries or fatalities, at a ratio higher than collisions that occur in dry roadway conditions. Therefore, it is of strong interest to identify and manage the locations where collisions are prone to happen under wet pavement surface or adverse weather conditions. This paper introduces a method to estimate precipitation exposure of roadway segments by linking weather station data to collision database. Subsequently, the corresponding crash rate for a subject location is...

A Dynamic Congestion Pricing Strategy for High-Occupancy Toll Lanes

Jang, Kitae
Chung, Koohong
2010

High Occupancy Toll (HOT) lanes are emerging as a solution to address the underutilization of High Occupancy Vehicle (HOV) lanes and also means of generating revenue for state department of transportation. This paper proposes a method for dynamically determining the HOT toll price in response to the changes in traffic condition and documents procedures for estimating parameters needed for the proposed pricing strategies: revenue maximization and delay minimization. The proposed strategies have been applied to 14-miles of freeway segment in the San Francisco Bay Area, and the findings...

Performance Measures for Complete, Green Streets: A Proposal for Urban Arterials in California

Sanders, Rebecca L.
Macdonald, Elizabeth
Anderson, Alia
2010

The California Department of Transportation (Caltrans or “Department”) manages more than 15,000 miles of state highways, ranging in scale and function from local streets to interstate highways. Historically, Caltrans has been governed by the principles of highway engineering, which focus on providing mobility to motorized vehicles. Over the past decade, however, the Department has joined in a national movement to better incorporate non-motorized transportation and community-level outcomes into its transportation decision-making framework, embodied by the approach known as "Complete...

Limitations of Data on Cell Phone Involvement in Collisions: A Case Study of California

Griswold, Julia B.
Grembek, Offer
2014

With the increasing prevalence of mobile technology and high-profile crashes bringing attention to distracted driving, data on cell phone involvement in collisions is critical for understanding the extent of the problem, examining the effectiveness of policies, and developing interventions to improve safety. Some limitations of existing data have been previously identified, but this paper examines the specific case of California’s collision data. Temporal, geographic, and jurisdictional trends are analyzed to identify the source and type of inconsistencies in the cell phone...

Observational Study of Cell Phone and Texting Use Among California Drivers 2015 and Comparison to 2011 through 2014 Data

Cooper, Jill F.
Ragland, David R.
Ewald, Katrin
Wasserman, Lisa
Murphy, Christopher J.
2015

In the 2015 observations, the majority of drivers (73.0%) drove alone, and 22.0% had one passenger in the car. The increase of drivers driving alone since 2014 (4.8%) and the decrease (3.5%) of drivers driving with one passenger is significant (Table 13).

Property Damage Crash Equivalency Factors for Solving the Crash Frequency-Severity Dilemma: Case Study on South Korean Rural Roads

Oh, Jutaek
Washington, Simon
Lee, Dongmin
2010

Safety interventions (e.g. median barriers, photo enforcement) and road features (e.g. median type and width) can influence crash severities, crash frequencies, or both. Both dimensions—crash frequency and crash severity—are needed to obtain a full accounting of road safety. Extensive literature and common sense both dictate that all crashes are not ‘created’ equal—with fatalities costing society more than 1000 times the cost of property damage only crashes. Despite this glowing disparity, the profession has not unanimously embraced or successfully defended a non-arbitrary severity...

Single-Vehicle Fatal Crash Prediction for Two-Lane Rural Highways in the Southeastern United States

Zhu, Hong
Dixon, Karen K.
Washington, Simon
Jared, David M.
2010

The rural two-lane highway in the Southeastern United States is frequently associated with a disproportionate number of serious and fatal crashes and as such remains a focus of considerable safety research. The Georgia Department of Transportation spearheaded a regional fatal crash analysis to identify various safety performances on two-lane rural highways and offer guidance for identifying suitable countermeasures to mitigate fatal crashes. The fatal crash data used in this study were compiled from Alabama, Georgia, Mississippi, and South Carolina. The database, developed for an...