Twin Cities Metro Area Ramp Meter Study FAQs

 

Oct. 2000 FAQs
Select a question When will the shutdown occur? Will all the ramp meters be turned off? Why did you decide to tell the public about when the shutdown would occur? What will the study cost? What are the study objectives? What will the consultant be measuring? How will the consultant measure customer satisfaction? Why is MnDOT doing this study? Does MnDOT support the study? Will there be citizen/community involvement in the study? Is the consultant taking into account changes in weather or lighting conditions? Will the HOV lanes and ramp-meter bypasses be open to single-occupant vehicles during the study? What will the ramp meters look like during the study? If the system collapses, will MnDOT stop the study? What do you think will happen when the ramps are shut down? Can I comment about the study? Are there other cities with ramp meters in operation? Where did ramp metering start? How many ramp meters have been installed since then? What are the objectives of ramp metering? Have evaluations of the effectiveness of ramp meters been done anywhere? Why do we have ramp metering? How much did MnDOT spend to install and perform any needed upgrades at the 430 ramps that are metered? If the 430 ramp meter system were to be installed today, what would it cost? Does MnDOT's traffic management and traveler information system include more than just ramp metering?

 

 

When will the shutdown occur?

The ramp-meter study that includes shutting off all ramp meters in the metro area will occur starting with the morning rush hour on Monday, October 16 and last from four to six weeks. The shutdown follows completion of a five week pre-study data collection effort which began on September 12. The pre-data collection was done to enable the consultant to compare the data collected "with" ramp meters against the data collected "without" ramp meters. Data analysis is expected to be complete by the end of the calendar year.

 

Will all the ramp meters be turned off?

Yes, all 430 ramp meters will be shut off during the study.

 

Why did you decide to tell the public about when the shutdown would occur?

The Ramp Meter Study Advisory Committee decided to notify the public a week in advance of the shutdown. The consultant decided that they will take into account the impact of any type of anticipatory behavior. The consultant estimates that it will take one to two weeks for traffic to settle down when the meters are turned off. The consultant believes that alerting the public could speed up this transition time.

 

What will the study cost?

The study will cost $651,600.

What are the study objectives?

Study objectives include:

• To fully explore the impacts of ramp metering on freeways, local roads, and on transit operations.
• To identify the public perception of ramp metering.
• To compare Minnesota’s ramp metering system and timing strategies with other regional systems across the country.

 

What will the consultant be measuring?

The consultant will study four freeway corridors that have been chosen as being representative of the system. The location of these corridors will not be made public, so as to maintain the integrity of the data. The consultant team will collect data that will help it evaluate the impacts of ramp metering on travel time, safety, travel time reliability/predictability, the environment and energy and volume (the number of vehicles the system carries). This data will be collected on both freeways and parallel alternate routes. Additionally, customer satisfaction will also be measured.

 

How will the consultant measure customer satisfaction?

The consultant plans to use a series of focus groups and a telephone survey of users of the system. They will measure individual traveler-oriented perspectives regarding ramp meters and ramp meter operation. In total, 1,540 system users will participate in the market research.

 

Why is MnDOT doing this study?

A bill, passed by the 2000 Legislature, requires that MnDOT study the effectiveness of ramp meters in the Twin Cities metro area by conducting a shutdown study before the next legislative session.

 

Does MnDOT support the study?

MnDOT is fully committed to conducting a scientific study of ramp meter effectiveness.

 

Will there be citizen/community involvement in the study?

Two committees are helping to guide and implement the study to ensure the involvement of a broad range of stakeholders.

• An Advisory Committee provides policy oversight and helped select the consultant. The committee also helped devise the proposed study work plan, measures of effectiveness and evaluation measures. David Jennings, President of the Greater Minneapolis Chamber of Commerce, chairs the Advisory Committee. Other organizations represented include:
• Association of Minnesota Counties
• Department of Public Safety - State Patrol
• Hennepin County Community Health Department
• Southwest Metro Transit Commission
• Four State Legislators
• FHWA
• Murphy Warehouse Company
• AAA
• Metropolitan Council
• Mn/DOT
• Citizens League
• Metro Transit
• City of Eagan
• A Technical Committee provides technical guidance, expertise and quality control. It also represents the public, and provides technical guidance to the consultant selection process, the study work plan and measures of effectiveness and evaluation methods. It is chaired by James Grube, Director of the Hennepin County Transportation Department. Organizations represented include:
• Pollution Control Agency
• Dakota County Highway Department
• City of Ramsey
• City of St. Paul
• Mn/DOT's Metro Division and Office of Investment Management
• Metropolitan Council
• City of Minneapolis
• Metro Transit
• Ramsey County Public Works
• FHWA

 

Is the consultant taking into account the changes in weather or lighting conditions that will occur in the before and after study? What about days with a high number of incidents?

 

Will the High Occupancy Vehicle (HOV) lanes and ramp-meter bypasses be open to single-occupant vehicles during the study?

The consultant intends to flag bad weather days (rain/snow), high incident days, and dark vs. light conditions (both during the "before" and the "after" data collection). Incidents are defined as crashes, stalled or stranded vehicles, and obstacles, such as spilled cargo. The data will be grouped and analyzed into separate categories. If there is a statistically significant difference between groups, the data will be analyzed separately and comparisons will be made for data under similar weather/light/incident conditions. Also, the consultant will analyze data across groups to identify differences in the effectiveness of ramp metering under varying weather/light/incident conditions.

 

What will the ramp meters look like during the study?

No. The HOV lanes and ramp-meter bypasses will operate as usual and will be open for buses, car/vanpools, and motorcycles during regular hours. The State Patrol will enforce these lanes and bypasses as usual.

 

If the system collapses, will MnDOT stop the study?

The study is a legislative mandate and MnDOT plans to carry out the study to its completion. There is a plan in place, however, should consideration need to be given to stopping the study mid-way through its completion, due to circumstances such as safety.

 

What do you think will happen when the ramps are shut down?

It would be inappropriate for MnDOT to speculate as to what will occur when the meters are shut off.

 

Can I comment about the study?

During the study an online comment form was available.

 

Are there other cities with ramp meters in operation?

The largest ramp metering system in North America is located in Los Angeles County with more than 1000 meters. Since 1989, the number of meters (nationwide) has increased from about 1,600 to about 2,300. By the end of 1999, at least 33 metro areas have meters operating, including: (Source: Ramp Metering in North America - 1995 Update, Federal Highway Administration,. June 1995)

 

Metropolitan Areas with more than 50 meters	Metropolitan Areas with less than 50 meters
Chicago, IL Los Angeles, CA Minneapolis/St. Paul, MN New York, NY Orange County, CA Phoenix, AZ Portland, OR San Diego, CA San Jose/San Francisco, CA Seattle	Atlanta, GA Columbus, OH Denver, CO Detroit, MI Fresno, CA Houston, TX Milwaukee, WI Northern Virginia, VA Riverside, CA Sacramento, CA San Antonio, TX San Bernardino, CA Toronto, ON

 

Where did ramp metering start in the country? In Minnesota?

Ramp metering has been around since 1963 when it was first installed on the Eisenhower Expressway (I-290) in Chicago. This first application involved a police officer who stopped traffic on an entrance ramp and released vehicles one at a time at a predetermined rate.MnDOT first installed meters in 1969 on I-35E. These were located on entrance ramps at Maryland Avenue and Wheelock Parkway in St. Paul.

How many ramp meters have been installed since then?

Yearly Ramp Meter Installation Count
1970 = 4 1971 = 2 1972 = 0 1973 = 0 1974 = 4 1975 = 33 1976 = 0 1977 = 0 1978 = 0 1979 = 11	1980 = 0 1981 = 0 1982 = 0 1983 = 0 1984 = 4 1985 = 7 1986 = 0 1987 = 0 1988 = 2 1989 = 67	1990 = 85 1991 = 64 1992 = 49 1993 = 41 1994 = 24 1995 = 0 1996 = 1 1997 = 0 1998 = 21 1999 = 8 2000 = 0

 

What are the objectives of ramp metering?

There are three broad objectives for ramp metering:

• Emphasis on safety – very low metering rates, let only a few cars enter the freeway
• Optimize travel safety and efficiency of the freeway system – let more cars enter the freeway than the first objective
• Regulate freeway operations for enhanced safety and mobility – regulate traffic entering the freeway to improve the spacing between vehicles, but allow as many cars onto the freeway so that surface street operations are not affected significantly

Minnesota has adopted the second objective.

 

Have evaluations of the effectiveness of ramp meters been done anywhere?

Some evaluations are relatively new (Houston and Atlanta), while others were performed over 15 years ago (Los Angeles, Portland and Sacramento) (most of MnDOT’s corridor specific evaluations were done in the late 70’s and early to mid ‘80’s. The results of those evaluations mirrored those shown in the table below).

Generally, there hasn’t been a great deal of difference in the findings of those individual evaluations despite the time separation.

Performance Measure	Location & Result
Travel time	Atlanta – 10% decrease in peak period Houston – 22% decrease in peak period Arlington – 10% decrease in peak period
Travel speed	Milwaukee – 35% increase in peak period Portland –155% increase in peak period Los Angeles – 15 miles per hour faster
Crash rate	Phoenix – 16% decrease during metered hours Milwaukee- 15% decrease in peak period
Crash frequency	Portland –43% decrease Sacramento – 50% decrease Los Angeles – 20% decrease
Driver hours saved	Sacramento – 50% decrease Los Angeles – 8,470 hours per day
Vehicle volume	Milwaukee – 22% increase in peak period Sacramento – 5% increase in peak period Los Angeles – increase of 900 vehicles per day
Gallons of fuel saved	Portland – 700 gallons per weekday
Benefit/Cost ratio	Atlanta – about 4:1 in year 1, about 20:1 after five years

 

Why do we have ramp metering? What function does it serve?

Ramp metering is one method of maximizing existing roadway capacity. Other reasons for ramp metering include:

• Increased freeway productivity
• Reduced crashes
• Promotion of safer operations by easing the merging of vehicles from entrance ramps
• Better managed traffic flow near a crash or vehicle breakdown
• Reduced impacts of recurring congestion due to heavy traffic demand
• Postponed occurrence of slow speed operation on freeways
• Reduced platoons of vehicles entering the freeway
• Decreased fuel consumption by reducing stop-and-go travel
• Improved air quality

 

How much did MnDOT spend to install and perform any needed upgrades/replacements at the 430 ramps that are metered?

Since 1970, MnDOT has spent a total of $3,170,300 to install and perform any needed ramp meter system upgrades.

 

If the 430 ramp meter system were to be installed today, what would it cost?

To install the 430 ramp meter system today would cost approximately $4.2 million or $9,600 per ramp.

 

Doesn't MnDOT's traffic management and traveler information system include more than just ramp metering? How much has that cost?

MnDOT's traffic management, incident management, and traveler information system is a comprehensive network which includes closed circuit television cameras, a fiber optic communications system, changeable message signs, real-time traveler information delivery systems (including the internet and broadcast radio and television), lane control signals, a computer system, automated data collection and detection, control room monitor and display equipment, Highway Helpers, the Traffic Management Center and ramp meters. Since 1970, MnDOT has spent approximately $54,250,000 to install, upgrade and expand that system to a point where it now manages the flow of traffic on approximately 210 miles of freeways in the Twin Cities metropolitan area.