Evaluation

Physical Environments Influencing Bicyclists’ Perception of Comfort on Separated and On-Street Bicycle Facilities

Li, Zhibin
Wang, Wei
Liu, Pan
Ragland, David R.
2012

This study investigates the impacts of physical environments on bicyclists’ perceptions of comfort on separated and on-street bicycle facilities. Based on a field investigation conducted in Nanjing, China, we find that physical environmental factors significantly influencing bicyclists’ perception of comfort on the two types of facility. Cyclists’ comfort is mainly influenced by the road geometry and surrounding conditions on physically separated paths while they pay attention to the effective riding space and traffic situations on on-street bicycle lanes.

Bicycle Commuting Market Analysis Using Attitudinal Market Segmentation Approach

Li, Zhibin
Wang, Wei
Yang, Chen
Ragland, David R.
2012

The market segmentation analysis for bicycle commuting can help identify distinct bicycle market segments and develop specific policies or strategies for increasing the bicycle usage in each segment. This study aims to use the approach of attitudinal market segmentation for identifying the potential markets of bicycle commuting. To achieve the research objective, the household survey is conducted to obtain the travelers’ attitudes towards their commuting travels. The factor analysis is used to explore the latent attitudes. The structural equation modeling (SEM) simultaneously estimates the...

Investigating the Associations Between Road Network Structure and Non-motorist Accidents

Zhang, Yuanyuan
Bigham, John M.
Ragland, David R.
Chen, Xiaohong
2014

Road networks channel traffic flow and can impact the volume and proximity of walking and bicycling. Therefore, the structure of road networks—the pattern by which roads are connected—can affect the safety of non-motorized road users. To understand the impact of roads’ structural features on pedestrian and bicyclist safety, this study analyzes the associations between road network structure and non-motorist-involved crashes using data from 321 census tracts in Alameda County, California. Average geodesic distance, network betweenness centrality, and an overall clustering coefficient...

Alcohol Consumption and Incidence of Workers' Compensation Claims: A 5-Year Prospective Study of Urban Transit Operators

Ragland, David R.
Krause, Niklas
Greiner, Birgit A.
Holman, Barbara L.
Fisher, June M.
Cunradi, Carol B.
2002

Numerous studies have linked alcohol impairment on the job to occupational injury. Few studies have looked at the association of nonwork drinking and occupational injury. This study examines first workers' compensation claims after a baseline assessment of alcohol consumption and other occupational variables in 1836 transit operators participating in a medical examination for driver's license renewal. A proportional hazard model was used for the analysis.

Individuals with higher alcohol consumption were more likely to be male, have more years of driving, and have a higher job-...

Traffic Volume and Collisions Involving Transit and Nontransit Vehicles

Ragland, David R.
Hundenski, Ronald J.
Holman, Barbara L.
Fisher, June M.
1991

This study reports an analysis of collisions occurring between public transit vehicles operated by the San Francisco Municipal Railway System (Muni), the public transit agency for the City of San Francisco, and nontransit vehicles. The analysis, focusing on weekday collisions during 1987, demonstrated a strong association between hourly transit collisions rates and hourly traffic volume. The collision rate varied from 0.01 per 1,000 Muni vehicle-hours of operation during the interval 5 a.m. to 6 a.m., a time of very low traffic...

Objective Stress Factors, Accidents, and Absenteeism in Transit Operators: A Theoretical Framework and Empirical Evidence

Greiner, Birgit A.
Krause, Niklas
Ragland, David R.
Fisher, June
1998

The authors used observational job analysis as a conceptually based technique to measure stress factors unbiased by worker appraisal with 81 transit driving tasks on 27 transit lines. Stressor dimensions included work barriers that interfere with task performance due to poor technical-organizational design, time pressure, time binding (autonomy over time management), and monotonous conditions. Line-specific average stressor values were assigned to 308 transit operators who mainly worked the particular line. Logistic regression analyses showed associations for high work barriers and...

Strategies for Reducing Pedestrian and Bicyclist Injury at the Corridor Level

Ragland, David R.
Grembek, Offer
Orrick, Phyllis
2011

Methods for identifying sites with potential for preventing traffic fatalities and injuries have been developed for vehicle-vehicle collisions. This study was funded by the California Department of Transportation (Caltrans) to develop methods for identifying sites where there is potential for significant reductions in pedestrian and bicyclist injury. Data from 1998-2007 from a 16.5-mile section of San Pablo Avenue (SR 123) in the San Francisco East Bay was used as a study area. Several approaches for identifying sites with high potential for reducing pedestrian and bicyclist injury were...

Estimation of Pedestrian Risk Exposure in Urban Areas : Case studies in the US and in France

Do, Minh-Tan
Grembek, Offer
Cerezo, Veronique
2013
The paper deals with the estimation of pedestrian risk exposure in urban areas. The approach proposed is based, on the one hand, on a spatial analysis technique called Space Syntax that characterizes the street integration - how streets are connected to each other - which gives rise to a natural movement of persons, and on the other hand, on land-use which acts as a multiplier or a divider of the original flows. Street integration is weighted by factors related to land use to better captures the heterogeneity of street-blocks. The method is applied to two radically different urban spaces: the...

California Intersection Decision Support: A Systems Approach to Achieve Nationally Interoperable Solutions

Chan, Ching-Yao
Cody, Delphine
Cohn, Theodore
Dickey, Susan
Greenhouse, Dan
Mak, Tony
Marco, David
Nguyen, Khoi
Misener, James A.
Nowakowski, Christopher
Ossenbrugen, Paul
Ragland, David R.
Shladover, Steven E.
Tan, Swe-kuang
Vanderwerf, Joel
Wang, Xiqin
Zabyshny, Aleksandr
Zennaro, Marco
2005

The overall IDS research plan was constructed to realize, in slightly more than three years, the requirements, tradeoffs assessment, and technology investigations necessary to define an IDS. Toward the end of the project we will combine our understanding of the problem definition, IDS technologies and our integration experience with a standard Caltrans intersection (with advanced controller) and design a deployable IDS demonstration that can be field tested.

Traffic Safety Among Latino Populations in California: Current Status and Policy Recommendations

Cooper, Jill F.
Wilder, Tammy R.
Lankina, Elena
Geyer, Judy A.
Ragland, David R.
2005

This report summarizes the information gained from two community forums held in Latino communities in California, provides an analysis of trends in injury and demographic data, and reviews best practices for increasing safety and preventing injury in Latino populations. It highlights pressing traffic safety needs and presents recommendations. It is our goal that this report will serve as a prototype for policy, enforcement and program development to address traffic safety issues for Latinos in California.