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...
6.10 Countermeasures to Improve Pavement Delineation Good pavement surface markings allow drivers to (a) detect and recognize curves earlier, (b) reduce speeds appropriately, and (c) adjust their lateral position. Table 6.3 provides design guidance for markings. Table...
6.8 Countermeasures for Improving Steering and Vehicle Control Through Curves Motorists retain better control of vehicles when curves conform with their expectations and typical behaviors. Several design strategies promote safer alignments (Table 6.2). Table 6.2...
6.6 Speed Selection on Horizontal Curves When establishing design speeds, account for functional/context classification, the legal speed limit, terrain type, anticipated vehicle volumes, level of surrounding development, expense, and design consistency. Procedure...
6.4 Influence of Perceptual Factors on Curve Driving Many motorists base curve speeds on their perception of road features and the apparent curve radius. The apparent curve radius is the radius as seen from the motorists’ perspective. Topography and road elements can...
