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Effectiveness of On-Ramp Signals

​​​On-ramp signals were first introduced in Illinois in 1963 on Chicago's Eisenhower Expressway. Several other states – including California, Minnesota, Washington and Nevada – use them to effectively keep freeway traffic moving. They also are used extensively throughout Europe, most notably in England, France, Belgium, Germany and the Netherlands.

The following table shows data from U.S. cities that use on-ramp signals (data based on 2013 studies).

​Performance Measure​Location and Result
​Travel timeAtlanta – 10 percent decrease in peak period
Houston – 22 percent decrease in peak period
Arlington – 10 percent decrease in peak period
​Travel speed ​Milwaukee – 35 percent increase in peak period
Portland – 15​ percent increase in peak period
Detroit – 8 percent increase
​Crash rate Phoenix – 16 percent decrease during metered hours
Milwaukee – 15 percent decrease in peak period
​Crash frequency​Portland – 43 percent decrease
Sacramento – 50 percent decrease
Los Angeles – 20 percent decrease
​Driver hours​Sacramento – 50 percent decrease
Vehicle volumeMilwaukee – 22 percent increase in peak period
Sacramento – 5 percent increase in peak period
Detroit – 14 percent increase in volume
​Gallons of fuel saved ​Portland – 700 gallons per weekday
​Emissions reduction Minneapolis – 1,160 tons annually
​Benefit-cost ratio ​Atlanta – benefits were four times greater than the cost after one year and 20 times greater after five years

7/20/2020 9:46 AM