Road Weather Management Program
photos of lightning, trucks plowing snow, an empty road before a storm, and an evacuation
Office of Operations 21st century operations using 21st century technologies

Best Practices for Road Weather Management Version 2.0

Best Practices > Publications > Publication Titles

Title:

Dynamics of a Variable Speed Limit System Surrounding a Bottleneck on a German Autobahn

Abstract:

This paper presents findings of an ongoing empirical study focusing on the identification and examination of several recurring freeway bottlenecks. It integrates the fusion of several traffic management and driver information data sources along an 18 km (11.2 mi) section of Autobahn 9 near Munich, Germany. Currently, this section of A9 uses a series of algorithms to determine the most appropriate speed limit based on three control strategies -- incident detection, harmonization and weather detection. The combination of data sources contributes to the further understanding of traffic dynamics and driver behavior prior to, during and after bottleneck activation. The primary focus of this paper has been the investigation of the variable speed limit and traveler information systems provided by means of overhead dynamic message signs throughout the segment in order to develop an improved understanding of the impacts they have on driver behavior and bottleneck formation/location. The system reduces the speed limit in order to control dense, but still flowing, traffic and it has been found that traffic continued to flow during congested periods at speeds ranging between 30-40 km/hr (19-25 mi/hr). These findings will be connected to a before-and-after comparison of the system to be done in the future in order to determine benefits and impacts of such a system.

Source(s):

84th Transportation Research Board (TRB) Annual Meeting, Portland State University and BMW Group. For an electronic copy of this resource, please direct your request to WeatherFeedback@dot.gov.

Date: 2005

Author:

Bertini, Boice, Bogenberger

Keywords:


Dynamic Message Sign (DMS)
Freeway management
Mobility
Motorist warning system
Speed
Speed management
Traffic control
Traffic management
Variable Speed Limit (VSL)
Weather information
Traveler information

PDF files can be viewed with the Acrobat® Reader®.
Office of Operations