Showing papers on "Traffic wave published in 1982"

Estimation of passenger-car equivalents of trucks in traffic stream (discussion and closure)

Abstract: The passenger-car equivalent (PCE) of a truck represents the number of passenger cars (basic vehicles) displaced by each truck in the traffic stream under specific conditions of flow A model is proposed for estimating PCE-values for vehicles under free-flowing, multilane conditions Some measure of impedance as a function of traffic flow is used to relate two traffic streams--one that has trucks mixed with passenger cars and the other that has passenger cars only PCE-values are related to the ratio between the volumes of the two streams at some common level of impedance A deterministic model of traffic flow (Greenshields') is used to estimate the impedance-flow relationship Three measures of impedance are considered, each of which will generate a separate PCE-value for a truck of given characteristics PCE-values are also shown to relate to speed and length of subject vehicles and to vary with the proportion of trucks in the traffic stream (Author)

Quality of traffic service

Abstract: The Two-Fluid Model has been used to model the quality of service in Austin and Dallas traffic networks. In addition, the physical interpretation of the model parameters is closely examined. Furthermore, the Two-Fluid Model is slightly modified to better predict the average minimum trip time and stop time per unit distance. Finally, the results of two ergodic experiments as well as data in very light traffic conditions have been used to investigate the consistency of the underlying assumptions of the Two-Fluid Model. The interrelation between the Two-Fluid Model and other macroscopic traffic models such as a simple fuel consumption model is also discussed. The report is concluded with a discussion of the use of time-lapse aerial photography in the investigation of the Two-Fluid Model assumptions and in the derivation of relations that may exist among the means of the speed, density, and flow in a traffic network. (FHWA)

Observation on Transit Delay at Traffic Signals

Abstract: This paper presents data from several studies of transit delay at traffic signals, and compares these data to analytical expressions and values assumed in research to estimate the value of various forms of signal priority for transit. It is concluded that the available empirical data tend to support the assumptions of platooning of vehicles at close signal spacings and the use of established formulas for average delay. Recommendations are made on techniques to estimate sample sizes for field data collection, and the appropriateness of certain assumptions for estimating the benefits of signal priority.

A Stochastic Analysis of a Tandem Delay System

Abstract: A basic model is proposed for traffic on a two-way, two-lane road which allows that successive queues of fast vehicles traveling behind slow vehicles in one lane may see the same pattern of overtak...