The Kansas City Scout program used ramp meters to improve safety on a seven mile section of I-435; before and after data indicated that ramp meters decreased crashes by 64 percent.

KC Scout ramp metering program on I-435

Date Posted

11/01/2012

Kansas City, Missouri, United States

I-435 and Metcalf Ave: Kansas City, Missouri,

United States

Identifier

2012-B00799

Ramp Metering 2011 Evaluation Report

Summary Information

The Kansas Department of Transportation (KDOT) and Missouri Department of Transportation (MoDOT) implemented the Kansas City (KC) Scout ramp metering pilot program to improve safety and traffic flow on a seven mile section of I-435 between Metcalf Avenue and the Three Trails Memorial Crossing. A total of seven interchanges were equipped with ramp metering systems designed to regulate on-ramp traffic volumes in response to prevailing freeway traffic conditions and reduce sudden weaving and braking movements adjacent to on-ramps to smooth traffic flow and increase throughput and safety.

The evaluation team collected traffic data in the study area before and after the ramp metering system was turned on in March 2010. An initial assessment was conducted in 2010 after six months of operations and then again in 2011 after 12 months of operations. Results from the 2011 report are highlighted below.

FINDINGS

The 12-month evaluation on I-435 indicated

That ramp metering decreased crashes in the study area by 64 percent
That ramp metering reduced the number of crashes that could be attributed to merging by 81 percent.

In general, ramp metering helped motorists merge more easily and move at a consistent rate within the corridor. Overall travel times and speeds were sustained at reliable levels despite increased traffic volumes.