PATH

TRACER: In-vehicle, GPS-based, Wireless Technology for Traffic Surveillance and Management

McNally, M. G.
Marca, J. E.
Rindt, C. R.
Koos, A. M.
2003

The fundamental principle of intelligent transportation systems is to match the complexity of travel demands with advanced supply-side analysis, evaluation, management, and control strategies. A fundamental limitation is the lack of basic knowledge of travel demands at the network level. Modeling and sensor technology is primarily limited to aggregate parameters or micro-simulations based on aggregate distributions of behavior. Global Positioning Systems (GPS) are one of several available technologies which allow individual vehicle trajectories to be recorded and analyzed. Potential...

Small Cars In Neighborhoods

Bosselmann, Peter C.
Cullinane, Daniel
Garrison, William L.
Maxey, Carl M.
1993

Focusing on neighborhood travel, this study first reviews the development of vehicles and roads suited to such travel. It then considers community development trends that might encourage or thwart the adoption and use of such vehicles. Demands for vehicles and travel patterns are then treated, followed by discussions of safety and regulation topics and cost benefit issues.

GPS-Aided Gyroscope-Free Inertial Navigation Systems

Park, Sungsu
Tan, Chin-Woo
2002

A gyroscope-free inertial navigation system uses only accelerometers to compute navigation trajectories. It is a low-cost navigation system, but its output error diverges at a rate that is an order faster than that of a conventional gyroscope-based system. So integration with an external reference system, such as the Global Positioning System, is necessary for long-term navigation applications. In this pa-per, an integrated GPS and gyroscope-free INS system is designed to achieve stable long-term navigation. The linear and nonlinear error models of a gyroscope-free INS are derived and are...

The Mass Transit Needs Of A Non-driving Disabled Population

Golledge, Reginald G.
Costanzo, C. Michael
Marston, James R.
1996

This paper examines further characteristics of the activity patterns of blind and vision impaired non-driving populations previously discussed in PATH Database Reference No. The report begins with an exploration of the activity patterns of blind or vision impaired people, followed by an evaluation of the impact of non-driving on employability and movement potential of the disabled non-driving group. The results of a survey of blind and vision impaired users of public transit facilities are then examined. Travel behavior characteristics and travel modes are studied. Possible assistive...

Monitoring The San Francisco Bay Area Freeway Network Using Probe Vehicles And Random Access Radio Channel

Linnartz, Jean-paul M. G.
Westerman, Marcel
Hamerslag, Rudi
1994

In this report, the authors describe a method of collecting real-time traffic data from probe vehicles automatically sending traffic reports to one or m ore base stations, connected to a traffic center by a wired communications network. Analyzing and computing road traffic and message traffic flows in the San Francisco Bay Area, the authors study several multi-disciplinary aspects of this data collection technique. The results presented in this report reveal that random access (ALOHA) transmission of traffic messages is a (spectrum) efficient, inexpensive and flexible method for collecting...

Development and Assessment of Selected Mobility Applications for VII: Principal Findings

Shladover, Steven E
Lu, Xiao-Yun
Nowakowski, Christopher
2011

This project has shown how connected vehicle systems, based on vehicle-vehicle and vehicle-infrastructure communication and coordination, can support the development of mobility-enhancing applications with the potential to transform the performance of the road transportation system. Three separate mobility-enhancing applications were developed, simulated, and tested, and their expected mobility benefits were estimated using simulations. Cooperative adaptive cruise control was shown to have a high potential for user acceptance, and when applied at the gap settings chosen by representative...

Assessing the Value of TMCs and Methods to Evaluate the Long Term Effects of ITS: Measuring Congestion, Productivity and Benefi t Flow from Implementation

Gillen, David
Cooper, Douglas
2004

The study carries out an evaluation of TMCs (traffic management centers) using three methodologies; case studies, performance based regressions and time series analysis. The study is an extension of previous work that assessed the contribution of different types of intelligent transportation investments and initiatives. However, this research sought to distinguish the separate contributions of the ITS investments from the synergies of integration under a traffic management center. Secondly, the research investigated the time dimension of benefits where we investigated if there was an 'S'...

Nonlinear Longitudinal Controller Development and Real-time Implementation

Lu, Xiao-Yun
Tan, Han-Shue
Empey, Dan
Shladover, Steven E.
Hedrick, J. Karl
2000

Keywords longitudinal control, car platooning, back-stepping control, multi-surface dynamic sliding mode control, integral filters, realtime control code This report presents the development of nonlinear longitudinal controllers and their realtime implementation for Automated Highway Systems (AHS) at PATH, U. C. Berkeley supported by the project MOU 331. The demo'97 realtime code was first reconstructed for further development. Based on the new framework, the implementation and comparison of nonlinear controllers in the longitudinal control for cars platooning and other maneuvers have been...

Reservation, Scheduling, and Navigation System for a Checkpoint DRT Service

Li, Yuwei
Foletta, Nicole
Elkabany, Ken
Yang, Fan
Wee, Anthony
Cassidy, Michael
2007

The report fully documents a prototype system that has been developed to serve Demand-Responsive Transit (DRT). The DRT service is provided by means of buses and has been proposed for deployment (as a pilot project) in Fremont, California. The service itself is to be deployed in a “hybrid” fashion; i.e., service alternates between a traditional fixed-route mode and the DRT mode from one bus trip to the next.The report describes the prototype systems from the perspective of the system users (i.e., customers, bus drivers and administrators). Further, the report describes system configuration...

Fmcw Mmw Radar For Automotive Longitudinal Control

David, William
1997

This report presents information on millimeter wave (MMW) radar for automotive longitudinal control. It addresses the fundamental capabilities and limitations of millimeter waves for ranging and contrasts their operation with that of conventional microwave radar. The report analyzes pulsed and FMCW radar configurations, and provides detailed treatment of FMCW radar operating at MMW frequency, its advantages and disadvantages as they relate to range and velocity measurements.