For a roadway posted at 40 MPH, how far in advance should the flagger station be set?

For a roadway posted at 40 MPH, the flagger station should be set approximately 305 feet in advance. This distance is determined based on the safe stopping distance for vehicles traveling at that speed. Flagging stations serve to give drivers ample time to react to changes in traffic conditions, such as a work zone ahead.

For roads with a speed limit of 40 MPH, the appropriate distance allows vehicles to slow down safely as they approach the work zone, taking into consideration factors like reaction time and braking distance. The 305 feet measurement comes from various guidelines which suggest a formula or rule of thumb that factors in these dynamics. Ensuring flagger stations are placed at this distance minimizes the risk of accidents and provides a buffer zone for both the workers and the travelers on the road.

The other distances provided as options do not align with the recommendations for a 40 MPH zone. They either do not allow enough distance for safe deceleration or are distances designed for other speed limits.