Work zone speed limit

In Florida:
Regulatory speeds should be established to route vehicles safely through the work zone as close to normal highway speed as possible. Traffic Control Plans (TCPs) for all projects must include specific regulatory speeds for each phase of work. This can either be the posted speed or a reduced speed. The speed shall be noted in the TCPs: this includes indicating the existing speed if no reduction is made. By virtue of Florida Statute 316.187, all regulatory speeds must be established on the basis of a traffic and engineering investigation. Designers should reduce speed only when the temporary geometry requires it. The justification for establishing work zone regulatory speeds different from normal speed limits must be included in the project file. The TCP and the project file will suffice as the traffic and engineering investigation. When field conditions warrant speed reductions different from those shown in the TCP, the contractor may submit to the project engineer, for approval by the Department, a signed and sealed study to justify the need for further reducing the posted speed or the engineer may request the District Traffic Operations Engineer (DTOE) to investigate the need. It will not be necessary for the DTOE to issue regulations for regulatory speeds in work zones due to the revised provisions of Florida Statute 316.0745(2)(b).
The same regulations apply to all types of roadways when warranted.
Regulatory speed signs in rural areas (interstate and non-interstate) are to be preceded by a “Reduced Speed Ahead” sign positioned as follows: Interstate (Rural) – 1000 ft. in advance; Non-Interstate (Rural) – 500 ft. in advance. Urban areas ordinarily do not require an advance sign, however, the sign may be included at the designer’s option. The regulatory speed and “Reduced Speed Ahead” signs are to be paid under the pay item for Construction Work Zone Signs (each per day). If the existing regulatory speed is to be used, consideration should be given to supplementing the existing signs when the construction work zone is between existing regulatory speed signs. For projects where the reduced speed conditions exist for greater than 1 mile in rural areas (non-interstate) and on rural or urban interstates, additional regulatory speed signs are to be placed at no more than 1-mile intervals. Engineering judgment should be used in the placement of additional signs. For urban situations (non-interstate), additional regulatory speed signs are to be placed at a maximum of 1000 ft. apart. The regulatory speed should not be reduced more than 10 mph below the posted speed, and never below the minimum statutory speed for the class of facility, without the approval of the District Traffic Operations Engineer and the appropriate District Director (See the Design Standards, Index 600).
On projects with interspaced work activities (such a interstate resurfacing) speed reductions should be located in proximity to those activities which merit a reduced speed, and not “blanketed” for the entire project.
To ensure credibility with motorists and enforcement agencies, temporary regulatory speed signs shall be removed or covered as soon as the conditions requiring the reduced speed no longer exist. Once they are removed or covered, the speed existing prior to construction will automatically go back into effect unless new speed limit signing is provided in the plans. The TCP phase notes shall indicate when to remove the regulatory reduced speed limit signs. When the regulatory speed is changed in a work zone, the permanent speed limit signs are to be removed or covered during the period when the work zone regulatory speed zones are in effect.
Portable Regulatory Signs (PRS) are used. The purpose of this type of device is to highlight the regulatory speed for the work zone. A portable regulatory sign is a portable trailer that has the regulatory speed sign mounted with flashing lights on each side of the sign. The lights are used to draw the driver’s attention to the regulatory speed.