Much effort has been devoted to the theoretical aspects of truck turning characteristics, but little has been done to test these theories by observing actual trucks turning. This study focused on the dimensions and turning characteristics of combination tractor-semitrailer vehicles negotiating four rural interchange ramp intersections in Wisconsin. An attempt was made to determine the adequacy of Wisconsin's intersection and ramp terminal design standards and to evaluate the ability of the California Department of Transportation (Caltrans) theoretical turning templates to describe the actual paths of turning trucks. It was found that Wisconsin's intersection design standards are adequate for existing trucks but only marginal for the new, longer trucks (such as Wisconsin's WB-62, which has an overall wheelbase of 61.7 ft). Also, the Caltrans turning templates adequately described the turning path of the most common truck observed operating at low speeds.
Abstract