01769213

Component

https://doi.org/10.1177/03611981211004181

The Performance Index (PI), a widely used composite measure of vehicular stops and delays, is one of the most popular traffic signal performance measures. Over the decades it has been used to achieve a proper balance between delays and stops. Its key component, the “stop penalty,” has been used to minimize excess fuel consumption from unnecessary stops caused by traffic control operations. In signal optimization practice this stop penalty, also known as the K factor, has been set as an invariable parameter with a relatively low value ~10 to 20. This paper questions this widely accepted practice. It first explains the origins and meaning of the PI and the significance of the K factor. Then, it lists various studies, discusses their inconsistencies, and introduces a new Fuel Consumption Intersection Control PI (FCIC-PI). The paper also presents findings from field data collection and compares them with the other studies, including some simulation results. Outcomes of these various findings show some inconsistencies, but all point to the existing practice being wrong: the K factor is a variable dependent on at least one important factor—cruising speed. The outcomes also indicate that K values should, if fuel consumption is to be minimized, be larger than currently used. Future research should confirm these findings with a larger field data set, investigate other factors that affect the stop penalty, and consider a family of other emission-related PIs. Finally, a new methodology should be developed to properly integrate these new PIs into signal timing optimization.

Data collected for the purpose of this research are privately owned by the corresponding author but could be shared with the research community, on request to the corresponding author. © National Academy of Sciences: Transportation Research Board 2021.

English

pp 690-702

2021-9

Transportation Research Record: Journal of the Transportation Research Board

Web

References (38)

Fuel consumption; Methodology; Optimization; Performance measurement; Simulation; Stopping; Traffic signal control systems; Traffic signal timing

Highways; Operations and Traffic Management; Planning and Forecasting

TRIS, TRB, ATRI

Apr 4 2021 3:09PM