Study finds 511 Systems can reduce traffic delays by 2.57 percent on average.
Longitudinal study of 511 systems in the United States finds widespread benefits and cost savings.
Made Public Date


United States

Mitigating Traffic Congestion: The Role of Intelligent Transportation Systems

Summary Information

511 systems, also called traveler information systems, were one of the first intelligent transportation system (ITS) technologies to see widespread deployment in the United States. These systems began as telephone based systems where travelers, specifically motorists, could dial 5-1-1 and get travel information such as traffic information. Over time these systems have evolved into complex travel information systems that use cameras, sensors, and other data sources to monitor and, in some cases, dynamically reroute, traffic in real-time. Additionally, some 511 systems now provide non-motorist oriented information such as public transport information, among other things.


Interested in the benefits of 511 systems, a research team at the London School of Economics analyzed the effects of these systems on traffic congestion and air pollution. To do this the researchers used 21 years of traffic data, specifically Texas A & M’s Annual Urban Mobility Scorecard and Highway Performance Monitoring Systems data, for the 99 largest Metropolitan Statistical Areas (MSAs) in the United States. These data were used to build a series of econometric models where the main dependent variable was congestion and the main independent variable was the presence of 511 systems.


Results suggest that 511 system adoption resulted in a 2.86 percent decrease in traffic congestion costs and 2.57 percent decrease in traffic delays, on average per MSA.

Mitigating Traffic Congestion: The Role of Intelligent Transportation Systems

Mitigating Traffic Congestion: The Role of Intelligent Transportation Systems
Publication Sort Date
Cheng, Zhi; Min-Seok Pang; and Paul A. Pavlou
London School of Economics and Political Science

(Our website has many links to other organizations. While we offer these electronic linkages for your convenience in accessing transportation-related information, please be aware that when you exit our website, the privacy and accessibility policies stated on our website may not be the same as that on other websites.)

Application Taxonomy

Goal Areas