Characterizing Emergency Vehicle Preemption Operation with High-Resolution Traffic Signal Event Data

This paper focuses on the use of timed colored Petri nets (TCPN) to study emergency vehicle (EV) preemption control problem. TCPN is adopted to establish an urban traffic network model composed of three submodels, namely, traffic flow model, traffic signal display and phase switch model, and traffic signal switch control model. An EV preemption optimization control system, consisting of monitoring subsystem, phase time determination subsystem, and phase switching control subsystem, is designed. The calculation method of the travelling speed of EV on road sections is presented, and the methods of determining the actual green time of current phase and the other phase are given. Some computational comparisons are performed to verify the signal preemption control strategies, and simulation results indicate that the proposed approach can provide efficient and safe running environments for emergency vehicles and minimize EV’s interference to social vehicles simultaneously.

Download Full-text

Applied High Resolution Traffic Controller Data Outcome Based Performance Measures With Gate-Down Confirmation Circuit

2010 Joint Rail Conference, Volume 1 ◽

10.1115/jrc2010-36081 ◽

2010 ◽

Author(s):

Thomas M. Brennan ◽

James R. Sturdevant ◽

Darcy M. Bullock

Keyword(s):

High Resolution ◽

Performance Measures ◽

Test Site ◽

Performance Measure ◽

Lessons Learned ◽

Event Data ◽

Real Time Traffic ◽

Railroad Tracks ◽

Warning Time ◽

Synchronization Performance

Track clearance green phases are used at railroad preempted intersections to provide time to clear the railroad tracks of highway vehicles before a train arrives. This paper describes preemption performance measures developed in Indiana that use high resolution, real-time traffic signal event data, and a gate-down confirmation circuit at an active railroad crossing. These performance measures are used to quantitatively assess the synchronization of the track clearance phase with the railroad gate position. Performance measure plots from over 4,000 preemption events over six months are presented. The lessons learned from the assessment of these performance plots are described along with changes made to the test site during the study period. The paper concludes with recommendations for incorporating a highway-railroad synchronization performance measure using the start of railroad active warning time as a surrogate gate-down confirmation circuit.

Download Full-text

Implementation Vision for Distributed Control of Traffic Signal Subsystems

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198196155400106 ◽

1996 ◽

Vol 1554 (1) ◽

pp. 43-47

Author(s):

Darcy Bullock

Keyword(s):

Distributed Control ◽

Traffic Management ◽

Intelligent Transportation System ◽

Adaptive Algorithms ◽

Intelligent Transportation ◽

Traffic Signal ◽

Emergency Vehicle ◽

Systematic Method ◽

Traffic Management System ◽

Advanced Traffic Management System

The developments that have led to the construction of the 2070 controller are reviewed. The intelligent transportation system community has proposed many features and user services that will likely use this new controller. In general, many of the functions proposed for this controller, such as emergency vehicle preemption, transit priority, weather monitoring, dynamic lane assignment, enhanced malfunction diagnostics, and adaptive algorithms, are all technically feasible. To achieve widespread deployment of systems that integrate several advanced traffic management system features, however, a systematic method for integrating a variety of distributed computing subsystems must be thoughtfully defined. The fundamental benefits of adopting a distributed control model for traffic signal subsystems are described and summarized.

Download Full-text