TURNS AND RETURNS: MISSED OPPORTUNITIES IN ROAD DESIGN

Proper provision for vehicle access and manoeuvring is required in the planning of most civil engineering projects in the UK. Four factors influence the impact of wheeled vehicles access and manoeuvring: vehicle type, incidence/productivity, engineering compliance, and visualisation. Software has been developed to verify planning projects against potential use by conventional and specialised vehicles, and to ensure quality and productivity. The AASHTO guidelines have been introduced to improve the standard of vehicle turn simulation. They incorporate four factors that influence a vehicle's turning path: speed, super-elevation, lateral friction and driver turn rate. Three-dimensional computer simulation programmes are being developed.