Equations to reproduce the 1984 AASHTO Green Book Case III-B and III-C passenger car sight distance values are developed. These equations produced values within 8% of the Green Book graphical values. Truck performance characteristics were selected on the basis of the information provided in the Green Book. Passenger car characteristics were then replaced with the truck characteristics to determine sight distance values for trucks. Values up to 3,200 ft were calculated. Field observations at intersections indicate that sight distances of such magnitude are not required. On the basis of a review of the Green Book procedures, specific recommendations are identified for consideration in future versions of AASHTO geometric design policy.
Abstract