01592112

Component

Capacity drop indicates that the queue discharge rate is lower than the road capacity. Due to the capacity drop, traffic delays increase once queues form. Researchers find that queue discharge rates vary in different traffic conditions. Empirical data shows that the queue discharge rate increases as the speed in congestion increases. Understanding what and how driver behaviors result in such variable queue discharge rates can help minimize traffic delays and eliminate congestion. However, as far as authors know, few efforts have been devoted to testing impacts of traffic behaviors on the variable queue discharge rate. This paper tries to fill in the gap. The authors investigate to what extent acceleration variety and reaction time can influence the queue discharge rate. It is found that the acceleration variety cannot reduce the queue discharge rate considerably. Modelling reaction time might be more important than modeling acceleration when giving capacity drop in car-following models. A multi-phase reaction time mechanism for giving variable queue discharge rates is proposed. That is, decreasing reaction time as the speed in congestion increases can give the same variable queue discharge rate as empirical observations. The research might indicate that motivating drivers to speed up earlier could benefit increasing queue discharge rates and minimizing delays.

This paper was sponsored by TRB committee AHB45 Standing Committee on Traffic Flow Theory and Characteristics. Alternate title: Microscopic Investigation into Capacity Drop: Impacts of Bounded Acceleration and Reaction Time

01584066

16-1530

English

21p

2016

Transportation Research Board 95th Annual Meeting

Digital/other

Figures; References; Tables

Acceleration (Mechanics); Highway capacity; Queuing theory; Reaction time

Queue discharge rate

Data and Information Technology; Highways; I72: Traffic and Transport Planning

Transportation Research Board Annual Meeting 2016 Paper #16-1530

TRIS, TRB, ATRI

Jan 12 2016 4:40PM