STULL ? Douglas County commissioners are poised to put the brakes on fast-moving vehicles detoured by a long-lasting construction project west of Lawrence.

Wednesday night, commissioners will consider posting speed limits on two gravel roads that have become unofficial detours for traffic being steered away from Stull Road.

A 2.3-mile section of Stull Road formally known as Douglas County Road 442 is being rebuilt from Douglas County Road 1029 to the Fox Run subdivision, less than a mile east of Stull. The $1.4 million project is to widen lanes, add shoulders and improve sight lines for drivers.

The road has been closed to through traffic since construction began Aug. 26. That has turned the road’s 3,600 daily drivers including those who live on Stull Road onto these alternate routes:

l North 1700 Road, which runs parallel to the construction zone by connecting Stull Road west of town with County Road 1029.

l East 400 Road, running north from Stull Road to U.S. Highway 40.

Commissioners will consider posting speed limits, ranging from 25 mph to 35 mph, on both gravel roads to improve safety, said Keith Browning, the county’s director of public works.

Without posted speed limits, he said, state law mandated that the speed limit on the roads is 55 mph, or a speed that is “reasonable and prudent” for existing conditions.

Residents have asked the Douglas County Sheriff’s Department to increase patrols in the area, but Browning said without lower limits the patrols might not do any good.

“It is difficult to prosecute a driver for exceeding a reasonable and prudent speed without that speed being specifically posted,” Browning said.

Browning is recommending temporary speed limits be posted:

l On North 1700 Road: 35 mph from East 050 Road to East 100 Road; 30 mph from East 100 Road to Douglas County Route 1023; 35 mph from County Route 1023 to a half-mile east of East 400 Road; and 30 mph for the one mile west of County Route 1029.

l On East 400 Road: 25 mph, for 0.6 mile north of Stull Road, then 35 mph from that point north to U.S. Highway 40.