Reason Foundation

http://reason.org
http://reason.org/news/show/states-should-consider-modest-incre

Reason Foundation

States Should Consider Modest Increases in Speed Limits

Baruch Feigenbaum
November 21, 2011, 4:45pm

While drivers in Europe and Asia can travel 87 miles per hour or more, drivers in most U.S. states cannot travel faster than 75 miles per hour. With safer cars and improved technology U.S. states should consider raising the speed limit on rural multi-lane divided expressways. 

What are the speed limits in other parts of the world? Parts of the Autobahn in Germany have no speed limits and rural speed limits in Poland and the United Arab Emirates are 87 miles per hour. In many European countries the rural speed limit is 81 miles per hour. These European and Asian countries are more densely populated than most U.S. states. 

Many states could safely raise their speed limit by five to ten miles per hour. Prior to the 1973 political oil crisis the speed limits in many states exceeded current levels. As a result of the 1973 events the federal government instituted a 55 miles per hour speed limit. This limit, in effect until 1988, required states to set 55 miles per hour as their top speed limit or lose federal transportation funding. With no national speed limit currently in effect states are free to raise their speed limits back to pre-1973 levels. At present many state speed limits are below their pre-1973 levels. 

Critics are opposed to higher speed limits for three reasons. First, many critics claim that increased speeds will increase accidents. However, studies have shown that increasing the speed limit reduces accidents. Researchers from the Michigan State Police found that the safest driving speed is the speed most motorists are already traveling. In addition, researchers have found that the gaps between drivers tightly obeying the speed limit and those exceeding the legal limit account for many accidents. A 5-10 mile increase would cause a smaller speed differential on many highways. Most traffic engineering guidebooks recommend setting the speed limit at the 85th percentile, the level at which 85 percent of people are driving. Further, the Federal Highway Administration has determined that increases of 5-10 miles per hour do not increase accident rates.

The second reason that many skeptics oppose higher speed limits on rural interstates is increased state populations. However most of these population gains have occurred in suburban areas and suburban drivers do not regularly travel on rural roads. Rural roads also have increased safety and technology features compared to 30 years ago. 

The third reason many oppose higher speed limits is fuel efficiency. Researchers have found that vehicles use the least amount of gasoline when traveling 55-60 miles per hour. In order to reach the 55 miles per hour most states had to lower their speed limits by 15-20 miles per hour. Yet the Department of Transportation found that the national 55 miles per hour speed limit only decreased gasoline usage by 1% at most. With proposed increases of 5 miles per hour, the total impact if all states raise their speed limits would be a 0.3% increase in gasoline use. Additionally, new federal fuel efficiency standards will greatly increase fuel efficiency. Increased purchase of total electric vehicles or hybrids will also contribute to lower gasoline consumption. Any increase in fuel use will not be significant. 

The ideal rural maximum speed limit differs by state. Below is a chart of the current speed limit, pre-1973 limit, and proposed new limit. The Proposed Speed Limit in the chart considers a states population, density, and location of rural interstates. 

State Speed Limits on Rural Interstates/Divided Expressways in Miles per Hour

State

Current Speed Limit

Proposed Speed Limit

Pre 1973 Limit

State

Current Speed Limit

Proposed Speed Limit

Pre 1973 Limit

Alabama

70

75

70

Nebraska

75

80

75

Arizona

75

80

75

Nevada

75

85

None

Arkansas

70

75

75

New Hampshire

65

70

70

California

70

75

70

New Jersey

65

70

70

Colorado

75

80

70

New Mexico

75

80

70

Connecticut

65

65

60

New York

65

70

65

Delaware

65

70

N/A

North Carolina

70

75

70

Florida

70

75

70

North Dakota

75

85

70

Georgia

70

75

70

Ohio

70

75

70

Idaho

75

85

70

Oklahoma

75

80

70

Illinois

65

75

70

Oregon

65

75

75

Indiana

70

75

70

Pennsylvania

65

70

65

Iowa

70

75

75

Rhode Island

65

65

60

Kansas

75

80

80

South Carolina

70

75

70

Kentucky

70

75

70

South Dakota

75

85

75

Louisiana

75

75

70

Tennessee

70

75

75

Maine

75

75

70

Texas

80

85

70

Maryland

65

70

70

Utah

80

85

70

Massachusetts

65

70

65

Vermont

65

70

65

Michigan

70

75

70

Virginia

70

75

70

Minnesota

70

75

65

Washington

70

75

65

Mississippi

70

75

70

West Virginia

70

75

70

Missouri

70

75

70

Wisconsin

65

75

70

Montana

75

85

None

Wyoming

75

85

75 

*Alaska, the District of Columbia, and Hawaii have no rural expressway mileage and are not included in the above chart.

**Current Speed Limit Source and Pre-1973 Speed Limit Source: State Departments of Transportation

Recently Louisiana, Maine, Oregon, and Texas have considered increasing their state speed limits. Other states should consider whether raising speed limits is appropriate. While highway safety is very important, many states should consider modest increases in their speed limit to transport people and goods more quickly from point A to point B.


Baruch Feigenbaum is Transportation Policy Analyst


Print This