5.12 Influence of Speed on Sight Distance When operating speeds are much faster than design speed, increasing sight distance to account for higher vehicle speeds can be a good option. Table 5.8 summarizes how different aspects of a road’s design influences operating...
5.10 Determining Passing Sight Distance Passing sight distance is the length of roadway downstream a motorist must be able to see to safely complete a passing maneuver. Safe completion means the motorist does not cut off the vehicles they are passing before they meet...
5.8 Determining When to Use Decision Sight Distance Decision sight distance is longer than stopping sight distance. Its use is appropriate in road environments where motorists (a) make complex or instantaneous decisions, (b) have difficulty perceiving information, or...
5.4 Determining Stopping Sight Distance Stopping sight distance is the distance a motorist traveling at a particular speed needs to stop their vehicle once they detect an object on the road. To determine stopping sight distance, use actual operating speeds if they are...
5.2 Key Components of Sight Distance Formally, sight distance is the length of road a vehicle travels before the driver completes a maneuver in response to an element, hazard, or condition that requires a change in the vehicles speed and/or path. Sight distance...
6.12 Signs on Horizontal Curves Use curve warning signs to communicate downstream changes in horizontal alignment to motorists. Signs need to include a directional arrow that indicates if a curve bends to the left or right. Advisory speed signs can also be used. Table...
