State changes country road speed limits
Unposted unpaved country roads will drop to 55mph; Unposted subdivision roads will be 30mph
by Wyoming Department of Transportation
June 6, 2011
Beginning July 1, the speed limit on unposted roads in subdivisions in Wyoming counties will be 30 mph, and the limit on unposted unpaved county roads will drop to 55 mph.
Speed limits on paved county roads will remain 65 mph, unless posted otherwise. Previously the 65 mph limit applied to all county roads, unless signs were posted indicating another limit.
The 2011 Legislature voted to extend the statutory 30 mph speed limit for city streets to county roads that pass through subdivisions, and to lower the limit for unpaved roads.
The University of Wyoming, Wyoming County Commissioners Association and WYDOT provided information to the Legislature about the changes.
A study completed by Dr. Kaled Ksabati, of the UW College of Engineering, found the risk of crashes on the county roads studied increased by 27 percent where speeds exceeded 55 mph. It also found that on nearly 94 percent of the unpaved county roads the average speed of vehicles was less than 45 mph.
WYDOT looked at the issue from the road design perspective and found that 45 mph is the upper limit on roads designed for low speeds, and 50 mph is the lower limit for roads designed for high speeds.
County road foremen and maintenance supervisors told legislators that at higher speeds the gravel gets thrown off unpaved roads, so a lower speed limit could reduce their maintenance costs.
The new law allows local authorities to post speed limits that vary from those statutory limits on specific road sections within their jurisdictions without having to get the approval of WYDOT, as previously required.
WYDOT will establish rules and standards for the local authorities to use to determine appropriate speed limits in a manner consistent with national standards.
"Training will be provided to county engineers or county road and bridge supervisors on what criteria to look at when doing a speed study on county road sections where the default limit appears to be inappropriate," said WYDOT Assistant Chief Engineer Gregg Fredrick. "They then present that information to a professional engineer, who evaluates it and recommends the speed limit for that portion of the county road."
Training for the county officials will be provided through the Wyoming Technology Transfer Center at the University of Wyoming.
The result will be a more cost-effective process for county commissioners to change a speed limit and still meet federal standards, Fredrick said. "Counties will be able to review, evaluate and post the appropriate speed limit based on local circumstances."
For road sections that need to be posted with a speed limit that varies from the new defaults, Fredrick said counties are eligible for funding assistance through the federal High Risk Rural Road Program, if a hazard such as a tight curve is the reason for the change.
Those funds are distributed by WYDOT and can be used for making safety improvements to rural roads, including installing hazard-warning and speed-limit signs.