01099216

Component

https://doi.org/10.3141/2071-03

http://scholar.google.com...ylen&publication_year=2008

Incidents on freeways cause large delays for road users. These delays depend largely on the capacity at the incident location, which is determined by the drivers’ behavior at the accident location. Few empirical facts are available on traffic operations during an incident. This paper presents high-quality videos of the traffic flow around two accidents recorded from a helicopter. From the collected images, traffic counts have been performed at the exact location of the incident. This has two advantages. First, the capacity at the bottleneck per lane could be estimated. Second, truck counts could be converted to passenger car units at the location of the bottleneck. Counts show that the (outflow) capacity of the remaining lanes is about 50% lower than the (free-flow) capacity of the same number of lanes. This means that the road capacity in the opposite direction is reduced by half by the rubbernecking effect. The capacity of the road in the direction of the accident is reduced by more than half because not all lanes are in use. The images provide information on the causes for the capacity reduction. A leader accelerates and the follower accelerates a short time later. The average time between these two accelerations is estimated at about 3 s, but the video also shows a large spread of these times. The results can be used to assess consequences of incidents, in an analytical way and in macroscopic or microscopic traffic simulators.

01118256

English

pp 19-25

2008

Transportation Research Record: Journal of the Transportation Research Board

9780309113465

Print

Figures (2) ; Maps (1) ; Photos (2) ; References (18) ; Tables (3)

Bottlenecks; Data collection; Helicopters; Highway capacity; Highway operations; Traffic congestion; Traffic counts; Traffic crashes; Traffic delays; Traffic flow; Traffic incidents; Traffic simulation; Videotapes

Rubbernecking

Highways; Operations and Traffic Management; I73: Traffic Control

TRIS, TRB, ATRI

Jan 29 2008 2:58PM

• Analysis and Modeling of Automobile Users’ Perceptions of Quality of Service on Urban Streets
• Calibration Potential of Common Analytical and Microsimulation Roundabout Models: New England Case Study
• Control-Type Selection at Isolated Intersections Based on Control Delay Under Various Demand Levels
• Default Values for Highway Capacity and Level-of-Service Analyses
• Delay at Unsignalized Intersections
• Driver Behavior and Gap-Acceptance Characteristics at Roundabouts in California
• Estimating Capacity of U-Turns at Unsignalized Intersections: Conflicting Traffic Volume, Impedance Effects, and Left-Turn Lane Capacity
• Implementing Actuated Signal-Controlled Intersection Capacity Analysis with Pedestrians
• Inclement Weather Impacts on Freeway Traffic Stream Behavior
• Indicators of Performance on Two-Lane Rural Highways: Empirical Investigation
• Microscopic and Macroscopic Approaches to Delay Estimation with Oversaturated Conditions
• Modeling Left-Turn Blockage and Capacity at Signalized Intersection with Short Left-Turn Bay
• Multimodal Level of Service for Urban Streets
• Testing Incremental Queue Accumulation Method Using Lankershim Boulevard NGSIM Data Set: A Replacement for HCM Signalized Intersection Uniform Delay and Queue Method in Los Angeles, California