Evaluating the Operational Features of Superelevation of Truck-Only Interchange Ramp with Simulation in General Regions

To reduce passenger car traffic flow interference and ensure driver safety, separation of passenger cars and trucks (SPCT) has been proposed. However, the current related codes, Guidelines for Design of Highway Grade-separated Intersections (hereafter Guidelines), have not made detailed provisions for designing truck-only interchange ramps (TOIRs). This paper examines whether detailed superelevation values (both maximum and recommended) ruled by code are applicable for TOIR and revises them. We select six-axle articulated trucks as designed vehicles and choose PMS as the mechanical calculation model of TOIR superelevation; we then refer to Japanese code to build an allocation model of superelevation and radius and use Trucksim software for simulation. The result indicates the proposed minimum limited radius for TOIRs is more reasonable than values in Guidelines; under different design speeds and radii, the proposed recommended superelevation values for TOIRs based on the new allocation model are safer than values in Guidelines.