Data collection

Airports and Bicycles: what are the obstacles and incentives for operators to improve bicycle access?

Orrick, Phyllis
Frick, Karen Trapenberg
2013

In this paper we use a case study approach to examine how airport operators are addressing bicycle access to their properties and the motivations and obstacles they face, in light of new policies to integrate bicycles, along with transit and walking, into transportation planning, design and construction, and to increase bicycles’ role in the transportation system. Eight influential elements emerged from our review of policy documents and research literature. We used them to guide interviews with key informants. The eight elements are: governance structure, location, access roads,...

Safe Routes to Transit Program Evaluation Final Report

Sanders, Rebecca L.
Weinzimmer, David
Dittrich, Heidi
Cooper, Jill F.
2014

Safe Routes to Transit (SR2T) was initiated in 2004 with the adoption of the San Francisco Bay Area’s Regional Measure 2 which established a $1 increase in Bay Area bridge tolls. The intended purpose of this funding was to support various transportation projects within the region in order to reduce congestion along the seven state-owned toll bridge corridors. Consistent with this purpose, the SR2T Program was awarded $20 million to fund enhancements to increase walking and cycling to regional transit stations. SR2T funds were used for the following improvements, among others: ssecure...

Variations in Teens' Perception of Risk Factors for Teen Motor Vehicle Collision Injuries

Chen, Katherine L.
Cooper, Jill F.
Grembek, Offer
Henk, Russell
Tisdale, Stacey M.
2014

Teen drivers, especially males, are known to be at greater risk of being involved in a motor vehicle collision than any other age group. While novice teen drivers’ primary risk factors are commonly known, less is known about what teens perceive as risk factors for peers getting hurt or killed in motor vehicle collisions. This mixed methods study uses survey data from the Teens in the Drivers Seat (TDS) program in California to explore (1) teens' perceived risk factors for motor vehicle collision injury; and (2) the relationship between perceived risks and age, gender, and driving...

Predictors of Nonstandard Helmet Use Among San Francisco Bay–Area Motorcyclists

Tsui, Casey K.
Rice, Thomas M.
Pande, Swati
2013
Objective: The use of helmets that do not comply with safety standards is common in California. The objective of this study was to describe the use of these nonstandard helmets among San Francisco Bay–area (SFBA) motorcyclists and to identify personal and motorcycle characteristics that are associated with the use of nonstandard helmets. Methods: A survey of 860 SFBA motorcyclists was conducted. Log-binomial regression was used to estimate risk ratios to compare probabilities of nonstandard helmet use. Results: Fifteen percent of motorcyclists reported wearing a nonstandard helmet sometimes...

Error Consideration for Geocoding Police Reported Collision Data in California

Bigham, John M.
Oum, Sang Hyouk
2014

Geographic Information Systems (GIS) are frequently used to analyze collision data. In order to 3 utilize GIS, the data must be geocoded, or assigned a latitude and longitude coordinate by 4 translating a descriptive location onto street network data. However, the ability for accurate 5 spatial analysis can be limited by geocoding errors that may occur due to limitations in data 6 collection technologies, incorrect data entry due to human error, or inaccurate street reference 7 data. In the state of California there is an increased opportunity for data entry errors, given the 8 long...

Estimating Pedestrian Accident Exposure: Automated Pedestrian Counting Devices Report

Bu, Fanping
Greene-Roesel, Ryan
Diogenes, Mara Chagas
Ragland, David R.
2007

Automated methods are commonly used to count motorized vehicles, but are not frequently used to count pedestrians. This is because the automated technologies available to count pedestrians are not very developed, and their effectiveness has not been widely researched. Moreover, most automated methods are used primarily for the purpose of detecting, rather than counting, pedestrians (Dharmaraju et al., 2001; Noyce and Dharmaraju, 2002; Noyce et al., 2006). Automated pedestrian counting technologies are attractive because they have the potential to reduce the labor costs associated with...

Estimating Pedestrian Accident Exposure: Protocol Report

Greene-Roesel, Ryan
Diogenes, Mara Chagas
Ragland, David R.
2007

Walking is a healthful, environmentally benign form of travel, and is the most basic form of human mobility. Walking trips account for more than 8 percent of all trips taken in California, making walking the second most commonly used mode of travel after the personal automobile (Caltrans, 2002). In addition, many trips made by vehicle or public transit begin and end with walking.

In spite of the importance and benefits of walking, pedestrians suffer a disproportionate share of the harm of traffic incidents in California. As noted above...

Integration of Light Rail Transit into City Streets

Korve, Hans W.
Farran, Jose I.
Mansel, Douglas M.
Levinson, Herbert S.
Chira-Chavala, T.
Ragland, David R.
1996

This report addresses the safety and operating experience of light rail transit (LRT) systems operating in shared (on-street or mall) rights-of-way at speeds that do not exceed 35 mph. It is based on agency interviews, field observations, and accident analyses of 10 LRT systems in the United States and Canada. These systems—in Baltimore, Boston, Buffalo, Calgary, Los Angeles, Portland, Sacramento, San Diego, San Francisco, and San Jose—provide a broad range of current LRT operating practices and problems.

The report provides information to facilitate the safe, orderly, and...

Relative Vulnerability Matrix for Evaluating Multimodal Traffic Safety

Grembek, Offer
2015

The multimodal transportation network includes a mix of inherently different modes. In addition to differences in price, range, and comfort of travel, these modes differ in mass and velocity, which correspond to different orders of magnitude in the kinetic energy carried. This discrepancy in kinetic energy affects both the level of protection of each mode, and the level of damage it can inflict on users of other modes. Unfortunately, accounting for both sides of a crash is often overlooked. While the quantities and variables of collected data continue to increase, the analyses conducted...

Using Variable Speed Limits To Reduce Rear-End Collision Risks Near Recurrent Bottlenecks

Li, Zhibin
Liu, Pan
Bigham, John M.
Ragland, David R.
2013

Rear-end collisions would occur if vehicle speeds decrease abruptly when encountering kinematic waves (KWs) emanating from active bottlenecks. This study aims to develop a control strategy in variable speed limits (VSL) to reduce rear-end collision risks near recurrent bottlenecks. Using the crash prediction model developed for rear-end collisions related to risky KWs, the effectiveness of VSL control strategies were evaluated in the cell transmission model (CTM). Several strategies were tested in sequence to determine the best case for risk reduction. Results of this study show that the...