Work zone speed limit

In Kentucky:
According to Kentucky’s Administrative Regulations, the Cabinet can reduce the speed limit by 10 mph in a highway work zone without an engineering or traffic investigation. Reductions greater than 10 mph require a study and approval of the Secretary of Transportation. The intent of this regulation was to give flexibility to the project engineer for reducing the speed limit when necessary. Based on observations, this system typically results in the speed limit being reduced 10 mph on a majority of projects involving high-speed roadways (55 mph and above) . The state has emphasized in training that construction in itself should not justify a reduction. It has been pointed out that the MUTCD states that “reduced speed limits should be used only in the specific portion of the temporary traffic control zone where conditions or restrictive features are present.” However, the state’s construction employees tend to post these reductions regardless of the type/level of ongoing construction.
According to Kentucky regulations, the speed limit can be reduced as allowed on any roadway. In practice, reductions are primarily used on high-speed roadways.
The standard communications devices would be typical side-mounted speed zone signs. In some cases, changeable message signs are used to emphasize that the speed limit is reduced.
The state’s law and regulations do not specifically address the hours of the day that speed reductions will apply. From the Division’s standpoint, speed signs are no different than any other traffic control device and should be removed/covered when not necessary. In practice, speed reductions are normally posted throughout the day regardless of whether workers are present. In rare cases, project engineers eliminate speed limit reduction when work is not being performed. (Double fines only apply when workers are present and unprotected.)
Speed limit signs are occasionally covered when not needed. In most cases, the speed limit signs are not covered. (Double-fine signs must be covered when not necessary.)
Kentucky does not use flashing beacons on its signs.
Additional note: Kentucky’s laws and regulations provide for the posting of double-fine signs within work zones. At the discretion of the project engineer, these signs may be placed if: (1) a worker is not routinely protected by a barrier wall, or (2) a condition exists which exposes a worker to traffic hazards. The signs are relocated as the work zone progresses and must be covered/removed when workers have not been present for more than a two-hour period of time. The fines are placed in a special fund, which is used to pay for increased enforcement of construction work zones.