KC Scout ramp metering program on I-435
Kansas City, Missouri, United States
Ramp Metering 2011 Evaluation Report
Summary Information
METHODOLOGY
Travel time surveys were used to evaluate vehicle speeds and travel times on I-435 before and after ramp meters were installed. The before data were calculated in 2007 and the after data were collected in 2010, after ramp meters were operational for more than six months. Evaluators used the floating car method to determine average vehicle speeds during morning (6:00 AM to 8:00 AM) and afternoon (4:00 PM to 6:00 PM) peak periods in eastbound and westbound directions.
FINDINGS
Speeds increased on several freeway segments and decreased on others. Most notable increases were observed on I-435 between the State Line Road and Wornall Road interchanges. The most notable decreases were observed in the eastbound direction during afternoon peak periods. Although some freeway segments experienced improved freeway speeds and others did not the net overall effect resulted in improved travel times after ramp meters were installed.
- Overall, travel times along I-435 improved when ramp metering was added to the corridor. The improvement is the result of a net overall effect of some freeway segments that experienced faster freeway speeds combined with those that did not.
The FHWA Travel Time Index for I-435 decreased after ramp meters were installed indicating the ramp metering system contributed to less delay. The Travel Time Index is defined as the ratio of the average travel time over the free flow travel time for a section of freeway. The following table drawn from the source report compares Travel Time Indexes for eastbound and westbound sections of freeway during morning and afternoon peak periods before and after ramp meters were operational.
Study Area |
Travel Time Index
2008-2009 Before Ramp Meters |
Travel Time Index
2010 After Ramp Meters |
Percent Decrease
|
|
---|---|---|---|---|
Morning Peak | I-435 Westbound |
1.10
|
1.08
|
1.8%
|
I-435 Eastbound |
1.05
|
1.04
|
0.95%
|
|
Afternoon Peak | I-435 Westbound |
1.20
|
1.15
|
4.2%
|
I-435 Eastbound |
1.33
|
1.30
|
2.3%
|