Work zone speed limit
In Delaware, speed limits are reduced in work zones where physical conditions of a roadway or conditions of the roadside change in ways that will make drivers less comfortable and therefore they will likely voluntarily slow down. Work zone speed limit reductions are implemented on a case-by-case basis depending upon the type of temporary traffic control being used. While DelDOT does not typically measure the 85th percentile speed, the requirement is that a reduced speed is set to match the driver’s perception that a lower speed is reasonable and is likely to result in a fairly tight range of speeds. All types of roadways follow the same speed limit guidelines, from tertiary to interstate. Static signs are always used to communicate speed limits. On occasion, static signs are supplemented by variable message signs to provide additional target value. DelDOT has recently begun the use of the W3-1 Speed Reduction Warning sign to warn motorists of reduced speeds in work zones. DelDOT has also started using the FINES DOUBLED IN WORK ZONES warning sign on projects located on limited access highways where speed limit reductions have been put in place. These signs are also used on a case-by-case basis, not for every project.