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Traffic Management Systems Performance Measurement: Working Paper #2

Banks, James H.
Kelly, Gregory
1997

Traffic Data System Improvement Plans were prepared for Caltrans Districts 1 1 (San Diego) and 12 (Orange County) as part of a research project on performance measurement for traffic management systems. The plans document data system objectives, data requirements, and existing data collection and management systems; evaluate the adequacy of existing systems; identify improvements and resource requirements; and document the districts’ priorities for action. Both districts have similar data systems, although Orange County’s is better developed. Both systems rely heavily on single-loop...

A Probabilistic Model And A Software Tool For AVCS Longitudinal Collision/safety Analysis

Tsao, H. S. Jacob
Hall, Randolph W.
1993

This paper develops a probabilistic model and a software tool for analyzing longitudinal collision/safety between two automated vehicles. The input parameters are the length of the gap between the two vehicles, the common speed prior to failure, the reaction delay of the following vehicle and a bivariate joint distribution of the deceleration rates of the two vehicles. The output includes the probability of a collision and also the probability distribution of the relative speed at collision time. The model is used to compare the safety consequences associated with the platooning and "free-...

TravInfo Evaluation (Technology Element) Traveler Information Center (TIC) Study: Operator Response Time Analysis

Miller, Mark A.
Loukakos, Dimitri
2000

TravInfo (TM) is an advanced traveler information system for the San Francisco Bay Area that began operation in September 1996 under a public/private partnership. The public sector component centers on the Traveler Information Center (TIC), TravInfo (TM)'s information gathering, processing, and dissemination hub. For two years, until September 1998, TravInfo (TM) was a Field Operational Test (FOT) sponsored by the Federal Highway Administration. During the FOT, the TIC was evaluated. This report documents the analysis of operator response time. Response times remained stable throughout the...

Dynamic Traffic Assignment For Automated Highway Systems: A Two-lane Highway With Speed Constancy

Tsao, H. S. Jacob
1996

Dynamic traffic assignment through analytical modeling and optimization has been widely accepted by the IVHS R&D community as a promising traffic control tool for understanding and relieving traffic congestion on conventional highways and city streets. Due to the completely controlled nature of AHS traffic, dynamic assignment of AHS traffic is even more promising. One added dimension of complexity associated with AHS dynamic traffic assignment is lane assignment. Lane changes, for fully utilizing AHS capacity or for exiting, incur disturbances to and hence reduction of longitudinal...

Highway Electrification: An Exploration of Energy Supply Implications

Wang, Quanlu
Sperling, Daniel
1987

The objective of this preliminary report is to explore the energy supply opportunities and implications of electrifying highways. An important assumption in this report is that the technology and general cost structure for generating and storing electricity does not change significantly in the future. In other words, we ignore the possible use of super conductive materials to store electricity during off-peak times, which, if feasible, would greatly reduce average electricity costs. A future report will examine the opportunities and implications of breakthroughs in superconductivity.The...

Experimental Characterization of Multi-Lane Freeway Traffic Upstream of an Off-Ramp Bottleneck

Munoz, Juan Carlos
Daganzo, Carlos
2000

This report describes field observations of multi-lane freeway traffic upstream of an oversaturated off-ramp. It is based on empirical evidence from freeway I-880 (northbound) near Oakland, California. The report presents two diagnostic tools that reveal hidden features of the traffic stream and, based on these findings, proposes congestion mitigation strategies that could work for similar locations with little or no construction.

On Fundamental Issues Of Vehicle Steering Control For Highway

Guldner, Jurgen
Tan, Han-shue
1997

This paper discusses fundamental issues in lateral control design for automatic steering of passenger cars within an Automated Highway System ( AHS). A detailed analysis using time and frequency domain tools together with physical insight into the vehicle dynamics is presented. Several design directions are investigated, both for look-down and look-ahead systems. In order to preserve the qualities of look-down systems, the concept of virtual look-ahead via additional yaw error and yaw rate error measurements is introduced. The authors conclude that proportional-type feedback design...

Vehicle Modeling and Verification of CNG-Powered Transit Buses

Hedrick, J. K.
Ni, A.
2004

This report will present the results of the initial study to develop an accurate working model of the 40 foot New Flyer Bus powered by the Cummins C8.3+ 280G CNG engine (Figure 1.1). The main focus of the study is the modeling of the vehicle dynamics using step input acceleration data. Other parts of the research include gear shifting and torque production from the CNG engine, all of which are required to produce a completely simulationcapable bus model.

Major Failure Events of Automated Highway Systems: Three Scenarios from the Driver’s Perspective

Tsao, H.-S. Jacob
Plocher, Thomas A.
Zhang, Wei-Bin
Shladover, Steven E.
1997

Automated Highway Systems (AHS) have the potential for offering large capacity and safety gains without requiring significant amounts of additional right-of-way. Since the general public will be the users of the AHS, human factors must play a pivotal role in the research and development of AVCS technologies and AHS operation. In two companion reports, three attributes critical to AHS human factors were identified and seven scenarios featuring variations in these attributes proposed. To ensure the identification of all major compounding attribute combinations, detailed operational events,...

Whence Induced Demand: How Access Affects Activity

Levinson, David
Kanchi, Seshasai
2000

Additional highway capacity, by increasing travel speed, affects the individual share of time within a 24-hour budget allocated to various activities (time spent at and traveling to home, shop, work and other), some activities will be undertaken more, others less. This paper extends previous research that identified and quantified induced demand in terms of vehicle miles traveled, by considering questions of what type of demand is induced and which activities are consequently reduced. This paper uses the 1990 and 1995 Nationwide Personal Transportation Survey and Federal Highway...