Road User Behavior

The Inclusion of Adult Vehicle Occupants in Matched Cohort Studies of Child Restraint Effectiveness: A Study of Potential Bias

Rice, Thomas M.
Anderson, Craig L.

Objective: To determine whether either the inclusion of adults in matched cohort studies of passenger vehicle occupants or modification of age effects by collision severity biases child restraint risk ratios biases estimate of child restraint effectiveness.

Methods: Monte Carlo data simulations were conducted to represent 10,000 collision-involved vehicles carrying a mix of children and adults. The effects of age category, adult seat belt use, child seat belt use, and child safety seat use were set to known values. Age was a modifier of the adult and child seat belt risk ratios and...

Bicycle Infrastructure that Extends beyond the Door: Examining Investments in Bicycle-oriented Design through a Qualitative Survey of Commercial Building Owners and Tenants

Orrick, Phyllis
Frick, Karen Trapenberg
Ragland, David R.

This paper presents the results of a qualitative survey of commercial owners, managers, and occupants in the City of Berkeley who have invested in on-site bicycle facilities such as secure parking, showers, changing rooms, and clothing lockers, what we are calling “bicycle-oriented design” (BOD). The sites represent a selection of building types common in the commercial building stock in U.S. cities. The research is designed to answer three questions about the use of BOD: (1) what were motivations behind the decision to invest in BOD (2) what are the challenges and rewards for...

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

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

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.

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...

Classification of Bicycle Traffic Patterns in Five North American Cities

Miranda-Moreno, Luis
Nosal, Thomas
Schneider, Robert J.
Proulx, Frank R.

This paper analyses bicycle ridership patterns using a unique database of automated bicycle counts from approximately 40 locations in five North American cities and along the Route Verte in Quebec. The cities involved in this study are Montreal, Ottawa, Portland, San Francisco, and Vancouver. Count data show that the bicycle volume patterns at each location can be classified as utilitarian, mixed utilitarian, recreational and mixed recreational. Study locations classified into each of these categories are found to have consistent hourly and weekly traffic patterns, despite important...

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

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

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.

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.

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...

Automated Assessment of Safety-Critical Dynamics in Multi-modal Transportation Systems

Medury, Aditya
Yu, Mengqiao
Bourdais, Cedric
Grembek, Offer

Recent mobility trends reveal that travel is becoming increasing multi-modal in nature. Given the increase in the emphasis on multi-modal mobility there is a need to efficiently account for the multi-modal safety challenges it introduces. In light of this, it is of immense concern that the corresponding improvements made to traffic safety have not been commensurate across all modes. In this regard, one of the major challenges associated with efficiently designing and planning for a safe multi-modal environment is a limited understanding of multi-modal traffic behavior as explained by...

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

Do, Minh-Tan
Grembek, Offer
Cerezo, Veronique
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...