Infrastructure

Combined Measure of Neighborhood Food and Physical Activity Environments and Weight-Related Outcomes: The CARDIA Study

Meyer, K
Boone-Heinonen, J
Duffey, KJ
Rodriguez, D
Kiefe, CI
Lewis, C
Gordon-Larsen, P
2015

Engagement in healthy lifestyle behaviors likely reflects access to a diverse and synergistic set of food and physical activity resources, yet most research examines discrete characteristics. We characterized neighborhoods with respect to their composition of features, and quantified associations with diet, physical activity (PA), body mass index (BMI), and insulin resistance (IR) in a longitudinal biracial cohort (n=4143; aged 25–37; 1992–2006). We used latent class analysis to derive population-density-specific (<vs.≥1750 people per sq...

Using Cooperative Adaptive Cruise Control (CACC)to Form High-Performance Vehicle Streams. Definitions, Literature Review and Operational Concept Alternatives

Shladover, Steven E.
Nowakowski, Christopher
Lu, Xiao-Yun
2018

Cooperative Adaptive Cruise Control (CACC) is a term that has been used rather loosely in recent years, such that different people visualize different functions and capabilities when discussing CACC systems. Thus, there are now multiple system concepts that have been described under the CACC label, and the functionalities included in these varied concepts can be quite different from each other. At the heart of each CACC concept is the merging of Adaptive Cruise Control (ACC), a subset of the broader class of automated speed control systems, with acooperative element, such a Vehicle-to-...

System Fault Detection in Human-Augmented Automated Driving

Cohn, Theodore
2001

Lateral control of a vehicle in the Automated Highway System (AHS) has been formulated and simulated as part of the hierarchical AHS control structure. In that structure, lateral control resides in the vehicle, and is implemented as a closed-loop control system with the lateral deviation of the vehicle from a reference position as a controlled variable and the steering angle or its rate as a controlling input. The PATH AHS scenario has assumed a road reference and sensing system based on magnetic markers equally spaced along a highway lane. Freedom in the selection of the polarity of each...

Exploratory Field Test of Early Fleet Niches for Hydrogen Fuel Cell Vehicles and Fueling Infrastructure

Martin, Elliot
Shaheen, Susan A., PhD
Lipman, Timothy E., PhD
Lidicker, Jeffrey
2009

Over the last several decades, hydrogen fuel cell vehicles (FCVs) have emerged as a zero tailpipe-emission alternative to the battery electric vehicle (EV). There are key questions about consumer reaction and response to operations and refueling of FCVs. This report presents the results of a “ride-and-drive” clinic series (n=182) held in 2007 with a Mercedes-Benz A-Class “F-Cell” hydrogen FCV. The clinic evaluated participant reactions to driving and riding in an FCV, as well as witnessing a vehicle-refueling event. The respondents entered the clinic with a strong interest in alternative...

Vehicle Assist and Automation Demonstration Report

California Department of Transportation (Caltrans)
Partners for Advanced Transportation Technology (PATH)
2017

Vehicle Assist and Automation (VAA) systems enable lane-keeping and precision docking of transit vehicles. They offer the opportunities of providing high-quality transit service within reduced lane widths. Sponsored by the United States Department of Transportation, this VAA project aimed to demonstrate the technical merits and feasibility of VAA applications in bus revenue service. The VAA Demonstration project was carried out through the four phases of design, development, deployment, and operational tests. In the design phase, the system architecture and requirements were finalized, and...

Development of Deployment Strategy for an Integrated BRT System

Miller, Mark A.
Tan, Chin-Woo
Golub, Aaron
Hickman, Mark
Lau, Peter
Zhang, Wei-Bin
2006

BRT mixes the flexibility of traditional bus transit service with an array of higher performance rail transit features. One of its advantages over rail, however, is its possibility for incremental and flexible deployment. With this flexibility and incremental nature comes a deployment process for BRT that is highly complex because numerous elements can be incorporated in any number of distinct phases. In almost all BRT deployments, ITS and advanced bus technologies have been applied to BRT, however, in less than a fully integrated manner. This project explores how deployment decisions can...

Community-Based Pedestrian Safety Training in Virtual Reality: A Pragmatic Trial

Schwebel, DC
Combs, T
Rodriguez, D
Severson, J
Sisiopiku, V
2016

Child pedestrian injuries are a leading cause of mortality and morbidity across the United States and the world. Repeated practice at the cognitive-perceptual task of crossing a street may lead to safer pedestrian behavior. Virtual reality offers a unique opportunity for repeated practice without the risk of actual injury. This study conducted a pre-post within-subjects trial of training children in pedestrian safety using a semi-mobile, semi-immersive virtual pedestrian environment placed at schools and community centers. Pedestrian safety skills among a group of 44 seven- and eight...

Obtaining Longitudinal Built Environment Data Retrospectively Across 25 years in Four US Cities

Hirsch, J
Meyer, K
Peterson, M
Rodriguez, D
Song, Y
Peng, K
Huh, J
Gordon-Larsen, P
2016

Neighborhood transportation infrastructure and public recreational facilities are theorized to improve the activity, weight, and cardiometabolic profiles of individuals living in close proximity to these resources. However, owing to data limitations, there has not been adequate study of the influence of timing and placement of new infrastructure on health over time. Methods: This protocol details methods of the four cities study to perform retrospective field audits in order to capitalize on existing longitudinal health data from the coronary artery risk development in young adults (CARDIA...

Using Cooperative Adaptive Cruise Control (CACC) to Form High-Performance Vehicle Streams

Shladover, Steven E
Nowakowski, Christopher
Lu, Xiao-Yun
Hoogendoorn, Raymond
2014

This research identifies the operational concepts for managing cooperative adaptive cruise control (CACC) vehicle maneuvering and traffic flows. This includes approaches for grouping the CACC vehicles, ranging from ad-hoc to centrally coordinated strategies, and the incentives that could be used to facilitate the vehicle clustering, both operational and financial. These are particularly important at low market penetrations, when the CACC vehicles are likely to be widely separated. The dissolution of CACC strings is also discussed, since this needs to be done carefully to avoid adverse...

Neighborhood Sociodemographics and Change in Built Infrastructure

Hirsch, JA
Green, GF
Peterson, M
Rodriguez, DA
Gordon-Larsen, P
2016

While increasing evidence suggests an association between physical infrastructure in neighborhoods and health outcomes, relatively little research examines how neighborhoods change physically over time and how these physical improvements are spatially distributed across populations. This paper describes the change over 25 years (1985–2010) in bicycle lanes, off-road trails, bus transit service and parks, and spatial clusters of changes in these domains relative to neighborhood sociodemographics in four US cities that are diverse in terms of geography, size, and population. Across all...