Data

Direct Ridership Model of Bus Rapid Transit in Los Angeles County

Cervero, Robert
Murakami, Jin
Miller, Mark A.
2009

A Direct Ridership Model (DRM) for predicting Bus Rapid Transit (BRT) patronage in Southern California is estimated. Attributes of bus stops and their surroundings constitute the data observations of the DRM, enabling a fairly fine-resolution of analysis to be carried out on factors that influence ridership. The best-fitting DRM revealed that service frequency strongly influences BRT patronage in Los Angeles County. High intermodal connectivity, with both feeder bus routes and rail-transit services, also significantly induces BRT travel. Population densities also contribute to BRT...

Evaluation of Traffic Data Obtained via GPS-Enabled Mobile Phones: the Mobile Century Field Experiment

Herrera, Juan C.
Work, Daniel B.
Herring, Ryan
Ban, Xuegang (Jeff)
Bayen, Alexander M.
2009

The growing need of the driving public for accurate traffic information has spurred the deployment of large scale dedicated monitoring infrastructure systems, which mainly consist in the use of inductive loop detectors and video cameras. On-board electronic devices have been proposed as an alternative traffic sensing infrastructure, as they usually provide a cost-effective way to collect traffic data, leveraging existing communication infrastructure such as the cellular phone network. A traffic monitoring system based on GPS-enabled smartphones exploits the extensive coverage provided by...

The Continuing Debate about Safety in Numbers—Data From Oakland, CA

Geyer, Judy
Raford, Noah
Ragland, David
Pham, Trinh
2005

The primary objective of this paper is to review the appropriate use of ratio variables in the study of pedestrian injury exposure. We provide a discussion that rejects the assumption that the relationship between a random variable (e.g., a population X) and a ratio (e.g., injury or disease per population Y/X) is necessarily negative. In the study of pedestrian risk, the null hypothesis is that pedestrian injury risk is constant with respect to pedestrian volume. This study employs a unique data set containing the number of pedestrian collisions, average annual pedestrian volume, average...

Space Syntax: An Innovative Pedestrian Volume Modeling Tool for Pedestrian Safety

Raford, Noah
Ragland, David R.
2003

This paper describes an innovative pedestrian modeling technique known as Space Syntax, which was used to create estimates of pedestrian volumes for the city of Oakland, California. These estimates were used to calculate pedestrian exposure rates and to create a Relative Risk Index for the city’s first pedestrian master plan. A major challenge facing planners, transportation engineers, and pedestrian-safety advocates is the lack of detailed and high quality pedestrian-exposure data. Exposure is defined as the rate of contact with a potentially harmful agent or event. Pedestrian exposure is...

Assessing the Variation of Curbside Safety at the City Block Level

Medury, Aditya PhD
Vlachogiannis, Dimitris
Grembek, Offer, PhD
2020

Investigating the dynamics behind the likelihood of vehicle crashes has been a focal research point in the transportationsafety field for many years. However, the abundance of data in today's world generates opportunities for deepercomprehension of the various parameters affecting crash frequency. This study incorporates data from many differentsources including geocoded police-reported crash data, curbside infrastructure data and socio-demographic data for thecity of San Francisco, CA. Findings revealed that the GFMNB model provides a better statistical fit than the FMNB andNB model in...

Traffic Injury on Tribal Lands in California

Ragland, David, PhD, MPH
Bigham, John
Oum, Sang Hyouk
Chen, Katherine
Felschundneff, Grace
2014

There is a disproportional risk of motor vehicle death and injury among American Indian/Alaska Native (AI/AN) populations in the United States. As home to the nation’s largest population of AI individuals, it is vital that California develop a better understanding of the factors contributing to this risk to guide the development and implementation of interventions to improve traffic safety for this population on the nearly 100 Rancherias and reservations in the state. However, there is very little data about the numbers and types of collisions, and driver and environmental factors...

Evaluation of Injury Severity Updates in California Collision Data

Bigham, John
Oum, Sang Hyouk
2018

Fatal or injury collisions in California must be reported to the California Highway Patrol (CHP) for inclusion in the Statewide Integrated Traffic Records System (SWITRS). After records have been entered into SWITRS they are made publicly available and are accessible through the CHP’s report and data retrieval site called I-SWITRS. However, records accessed in SWITRS are considered provisional and can be updated several years after initial entry. This includes the injury severity level of collisions. If the collision data was accessed prior to an injury severity update, the agency...

Low Income Childhood Pedestrian Injury: Understanding the Disparate Risk

Johnson, Emily
Geyer, Judy A
Rai, Nirmeet
Ragland, David R
2004

A leading cause of death and injury to children is being struck by a motor vehicle. A disproportionate number of injured child pedestrians are of low socioeconomic status. The relationship between socioeconomic status and pedestrian injury is poorly understood. The existing literature is limited by the lack of pedestrian exposure data, a common measure of risk, and a clear conceptual framework for the interaction between socioeconomic status and pedestrian injury. Another issue is the limited availability of injury data. This paper proposes a model for understanding child pedestrian...

HOV Lane Configurations and Safety Performance of California Freeways – An Investigation of Differential Distributions and Statistical Analysis

Jang, Kitae
Chan, Ching-Yao
2009

From a recent study of safety evaluation of HOV-equipped freeways, it was found that limited-access HOV lanes appear to have a safety performance disadvantage when measured by collision distribution or collision rates for the HOV lane alone and for the HOV and left lanes combined. This paper describes the work performed to verify the statistical significance of related findings. Several statistical tests were used: empirical cumulative density function (CDF), Kolmogorov-Smirnov Tests, and comparison of means based on Poisson Distributed Samples. The conclusion that continuous-access HOV...

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...