Current guidelines arguably do not properly address how much priority high-occupancy vehicle (HOV) lanes should be over general-purpose (GP) lanes. In response to this issue, this study developed a scheme to measure HOV speed priority via mathematical derivation. The concept of vehicle occupancy was incorporated to reflect the HOV core value－carrying more persons in fewer vehicles. As traffic increases, the scheme leads to HOV lanes' speed increasingly greater than GP lanes’. Contrasts were made between the proposed scheme and the conventional travel time saving principle. Two case studies were implemented; the local one indicates that Taiwan’s first HOV lane was under-prioritized while the foreign one shows that the HOV lane of SR-60 in California was well-prioritized. The results can be used to further assess the necessity of HOV policy adjustment.
2015 Eastern Asia Society for Transportation Studies