Principal Investigator: Ghulam Bham
Sponsors & Partners
Missouri Department of Transportation
About this Project
Brief Project Description & Background
This research project will determine the effectiveness of the Variable Speed Limit (VSL) system on I-270/I-255 corridor in St. Louis County, Missouri.
The objectives of the project are: i) Evaluate the impact of Variable Speed Limit on traffic flow and safety, ii) Evaluate the driver compliance of posted speed limit, and iii) Assess the perception of roadway users including law enforcement personnel
The potential benefit of the study is to find measurable indications of success with the system. The purpoted benefits of the VSL system are improvement in the traffic flow, speed harmonization and vehicle safety. Desired output from the study is a report on findings with recommendations for improvements.
The proposed project will determine the effectiveness of the Variable Speed Limit (VSL) system installed on I-270/I-255 corridor in St. Louis County, Missouri. The purported benefit of the VSL system is an improvement in the traffic flow and vehicle safety. The objectives of the evaluation are as follows: i) Evaluate the impact of VSL on traffic flow and safety, ii) Evaluate the driver compliance of posted speed limit, and iii) Assess the perception of roadway users including law enforcement personnel To determine the effectiveness of the VSL system, this project will evaluate the system based on the following performance measures as a minimum: i. User average speeds by posted speed limit and direction ii. Speed limits during peak periods by direction iii. Average traffic volumes during peak periods by direction iv. Travel times by direction v. Speed limit compliance by posted speed limit and direction vii. Evaluation of delay and queue clearance time associated with crashes. The performance measures will be evaluated based on data collected and used in the VSL system decision-making process, which is carried out currently over different points along I-270/I-255. The statistical analysis of the aforementioned data will show if there is a significant difference in traffic flow, safety and driver compliance between the deployed VSL system and a pre-deployment/non-VSL corridor. A final report will document the evaluation results of I-270/I-255.
Technology Transfer Activities
This research project supports the MATC theme areas of improving traffic flow, and minimizing risk by improving traffic safety.