Freeway Management > Ramp Control > Ramp Metering
In Salt Lake Valley, Utah a ramp metering study showed that with an 8 second metering cycle, mainline peak period delay decreased by 36 percent, or 54 seconds per vehicle.(March 2004)
In Minneapolis-St.Paul, an evaluation of the effectiveness of ramp meters on four test corridors showed that the number of commuters who supported a complete ramp meter shutdown declined significantly from 21 percent in 2000 to about 14 percent in 2001.(10 May 2002)
In Minneapolis-St.Paul, an evaluation of the effectiveness of ramp meters on four test corridors showed that freeway travel speeds decreased 5 to 10 percent and freeway travel times increased 5 to 10 percent between 2000 and 2001.(10 May 2002)
In Minneapolis-St.Paul, an evaluation of the effectiveness of ramp meters on four test corridors showed that the number of crashes recorded for the interim period with reduced ramp metering capacity was 15 percent higher that the average number of crashes measured for the previous fully metered periods. (10 May 2002)
The CORSIM simulation model has been used to estimate ramp metering speed improvements at the merge influence area under different ramp and mainline volumes, acceleration lane lengths, and number of lanes conditions, and the simulated outputs show that the average speeds at the merge influence areas increase when on-ramp junctions are metered, and that the increase is most prevalent under high traffic volumes, short acceleration lane, and low number of mainline lanes. (13-18 January 2002)
A simulation study in Minneapolis-St. Paul estimated that ramp metering decreased total system travel time by 6 to16 percent and increased average mainline speeds by 13 to 26 percent.( 13-17 January 2002)
A simulation study in Minneapolis-St. Paul estimated that ramp metering saved 2 to 55 percent of the fuel expended at each ramp.( 13-17 January 2002)
Simulations indicated that using a decision support tool to select alternative traffic control plans during non-recurring congestion in the Disney Land area of Anaheim, California could reduce travel time by 2 to 29 percent and decrease stop time by 15 to 56 percent. (December 2001)
A simulation study of existing ITS (traveler information, ramp metering, and DMS) on a Detroit freeway demonstrated how these technologies can increase average vehicle speed, decreased average trip time, and reduce commuter delay by as much as 22 percent.(July 2001)
A simulation study of existing ITS (traveler information, ramp metering, and DMS) on a Detroit freeway demonstrated how these technologies were beneficial to corridor capacity.(July 2001)
Most drivers believed that traffic conditions worsened when the Minneapolis-St. Paul ramp metering system was shut down and 80 percent supported reactivation.(February 2001)
When the ramp metering system on Minneapolis-St. Paul freeways was shut down, speeds fell by seven percent. (February 2001)
When the ramp metering system on Minneapolis-St. Paul freeways was deactivated, crash frequency increased by 26 percent.(February 2001)
Net annual vehicle emissions increased by 1,160 tons and fuel consumption decreased by 5.5 million gallons when the ramp metering system on Minneapolis-St. Paul freeways was shut down.(February 2001)
Volume decreased by 9 percent and peak period throughput was reduced by 14 percent when the ramp metering system on Minneapolis-St. Paul freeways was deactivated.(February 2001)
A study found that the benefit-to-cost ratio of the Minneapolis-St. Paul ramp metering system was 15:1.(February 2001)
Adaptive signal control integrated with freeway ramp meters in Glasgow, Scotland increased vehicle throughput 20 percent on arterials and 6 percent on freeways.(January 2000)
A survey of drivers in Glasgow, Scotland, found that 59 percent of respondents thought that ramp metering was very helpful or fairly helpful.(January 2000)
Adaptive signal control integrated with freeway ramp meters in Glasgow, Scotland improved network travel times by 10 percent.(January 2000)
A six year evaluation of freeway ramp metering in Arizona found that that the system reduced sideswipe accidents on the mainline by smoothing traffic flow, but increased rear-end accidents on entrance ramps where vehicles were required to slow down or stop unexpectedly.(August 1999)
In Glasgow, Scotland a freeway ramp metering system installed at an entrance ramp to the M8 motorway reduced the frequency of early merging by 29 percent.(12-16 October 1998)
In the St. Paul, Minnesota region ramp metering has increased throughput by 30 percent and increased peak period speeds by 60 percent.(November 1997)
The delay reduction benefits of improved incident management in the Greater Houston area saved motorists approximately $8,440,000 annually.
(7 February 1997)
A 1995 North American survey of traffic management centers using ramp metering, identified reductions of 15 to 50 percent in freeway crashes.(June 1995)
In Europe, ITS evaluation reports show that ramp metering can improve freeway capacity by 5 to 13 percent.(1994-1998)
In Long Island, New York, ramp metering and traveler information increased freeway speeds by 13 percent despite an 5 percent increase in vehicle-miles traveled during PM peak periods.(January 1992)
The cost of O&M at the Arizona TMC was estimated at $2 million per year.(January 2006)
The annualized life-cycle costs for full ITS deployment and operations in Tucson were estimated at $72.1 million. (May 2005)
A modeling study evaluated the potential deployment of full ITS capabilities in Cincinnati. The annualized life-cycle cost was estimated at $98.2 million.(May 2005)
The annualized life-cycle costs for full ITS deployment and operations in Seattle were estimated at $132.1 million.(May 2005)
TMC central hardware costs can exceed $200,000 if regional communications and system integration are required.(5 August 2004)
The $106 million capital cost for CommuterLink - the Salt Lake City, Utah advanced transportation management system - includes numerous components such as a signal system, ramp metering, traveler information dissemination, traffic surveillance and monitoring, and fiber optic network.(March 2004)
The cost of a freeway ramp metering system in Denver, Colorado was estimated at $50,000 plus the cost of communications.(November 2001)
Minnesota DOT estimated ramp metering operations for FY 2000 were $210,000.(May 2001)
