Roads/Highways

Seamless Travel: Measuring Bicycle and Pedestrian Activity in San Diego County and its Relationship to Land Use, Transportation, Safety, and Facility Type

Jones, Michael G.
Ryan, Sherry
Donlon, Jennifer
Ledbetter, Lauren
Ragland, David R.
Arnold, Lindsay
2010

This paper provides the data collection and research results for the Seamless Travel project. The Seamless Travel Project is a research project funded by Caltrans and managed by the University of California Traffic Safety Center, with David Ragland, PhD., as the Principal Investigator and Michael Jones as the Project Manager. The project is funded by Caltrans Division of Innovation and Research and is being conducted by the Traffic Safety Center of University of California Berkeley and Alta Planning + Design.Measuring bicycle and pedestrian activity is a key element to achieving the goals...

Address Resolution in One Lane Automated Highway Systems

Bana, Soheila V.
Varaiya, Pravin
1999

Address Resolution Protocols (ARP) are used in Automated Highway Systems (AHS) to establish communication among vehicles. The purpose of the ARP is to determine the network address of neighboring vehicles. We are proposing an innovative solution that takes advantage of the automated road infrastructure. For providing addresses initially and uses the communication network itself for updating the network communication addresses in a one lane automated highway system. The protocol has been modeled using PROMELA [1], and simulated and verified by SPIN [2]. SPIN is a tool for analyzing the...

Freeway Performance Measurement System (PeMS)

Chen, Chao
2003

The freeway Performance Measurement System (PeMS) collects real time traffic data from sensors and generates performance measures of vehicle miles traveled, hours traveled, and travel time. This project is sponsored by the California Department of Transportation (Caltrans). PeMS provides tools and reports for traffic planners, operators, and engineers. It has a Web interface. Growing traffic demand in metropolitan areas has far outpaced increases in freeway lane-miles in the United States. The solution to congestion lies in increasing the efficiency of existing infrastructure. Performance...

Field Experiments Demonstrate Fuel Savings for Close-Following

Michaelian, Mark
Browand, Fred
2000

There are only two ways to increase the throughput of vehicles on a highway—either construct more freeway lanes, or accommodate a shortened average spacing between individual vehicles (while maintaining speed). Providing a rational means for close-following is an attempt to accomplish the latter. The maximum throughput for a typical freeway lane is about 2000 vehicles/hour, and is roughly independent of the attributes of any particular freeway. The number is remarkably inelastic varying little over the past twenty years in spite of great improvements in the design of freeways and in the...

New Approach to Bottleneck Capacity Analysis: Final Report

Banks, James H.
2006

A capacity analysis approach intended as an alternative to the traditional Highway Capacity Manual (HCM) method was evaluated. One- and two-stage models of pre-queue and queue discharge flow (each of which might be thought of as representing “capacity” in some sense) were developed and compared with one another and the HCM method. Two-stage models related capacity flows to intervening variables, including average time gaps (average time separations between the rear of a vehicle and the front of one following it) in the critical lane (that with the highest flow rate) and the critical lane...

Transient Aerodynamic Effects on a Four-Car Platoon During Passing Maneuvers: Data Summary

Tsuei, L.
Hedrick, J. K.
Savas, O.
1999

In order to provide reliable control algorithms on PATH automated highway system, knowledge of the transient aerodynamic forces is important from the point of the controlla- bility of the platoon and individual vehicles. In a passing maneuver, the platoon members may experience severe aerodynamic forces and yaw moment when another vehicle overtakes. Similar phenomenon can be seen in our daily life as one car passes the other but much more complicated flow field is expected when the interaction involves in a multi-vehicle platoon. It is the purpose of this study to quantify the unsteady...

Rest Areas – Reducing Accidents Involving Driver Fatigue

Banerjee, Ipsita
Lee, Joon ho
Jang, Kitae
Pande, Swati
Ragland, David
2010

Rest areas are a countermeasure for fatigue; what role do they play in fatigue-related freeway collisions? The present study spatially evaluates fatigue collisions. In California, of 2,203,789 highway collisions recorded between 1995 and 2005, fatigue collisions accounted for 1.3% (‘strict’ definition of fatigue) and 9.7% (‘expanded’ definition). Collisions in the vicinity of rest areas were investigated using two different approaches: 1. 10-miles up/downstream of rest areas 2. Distance traveled from rest areasSample t-tests indicated that both fatigue and non-fatigue collisions decreased...

Highway Traffic Data Sensitivity Analysis

Lu, Xiao-Yun
Coifman, Benjamin
2007

This report is divided into two parts:•Part I - Highway Traffic Data Sensitivity Analysis in Systems Approach. This work has been conducted by Dr. Xiao-Yun Lu at California PATH, U. C. Berkeley.•Part II - Empirical and Analytical Results for Sensitivity to Loop Station Spacing. This work has been conducted by Benjamin Coifman in Civil Engineering, Ohio State University.Since the aspects of the problem considered and approaches adopted by the two are different, it is thus necessary to separate the report into two parts. Each part is self-content.

Lessons in Network Management: Cross-Industry Comparisons and Implications for ITS Development

Horan, Thomas A.
Reany, William
2002

This report provides an historical and case study analysis of policies aimed toward the management of complex systems, with specific reference to the role of public policy and technology in balancing surface transportation system demand and supply. Three case studies form the crux of the paper energy management, airport management, and Internet growth. Lessons from these case studies are then applied to the circumstance of ITS deployment to manage surface transportation in California. Following an introductory section (1), section 2 provides an historical analysis of the forces with have...

High Occupancy Vehicle (HOV) System Analysis Tools: Statewide HOV Facility Performance Analysis

Jang, Kitae
Chan, Ching-Yao
Du, Yao-Qiong
Chu, Lianyu
Yang, Ming-Hsun
Recker, Will
2012

The two most common types of high occupancy vehicle (HOV) lanes in California are continuous access, prevalent in Northern California, and buffer-separated limited access, prevalent in Southern California. This report describes the evaluation of operational performance of HOV facilities in several regions in California with different access types as well as a before-after comparative study of California facilities where access types were converted in recent years. A set of performance measures were defined and selected to indicate how well the HOV facilities achieve intended goals –...