Evaluation of exclusive bus lanes in a tri-modal road network incorporating carpooling behavior

This paper considers the evaluation of exclusive bus lanes (EBLs) in the road network with three travel modes: bus, solo driving, and carpooling. A tri-modal transportation network equilibrium model is developed to analyze the effects of EBLs under three different policies: (i) no EBLs (called Policy 1); (ii) EBLs can only be used by bus (called Policy 2); and (iii) EBLs can be used by both bus and carpooling modes (called Policy 3). By taking into account both EBLs setting scheme and bus frequencies, a combinatorial optimization model is proposed to test the performance of the tri-modal transportation system. In a traffic corridor case with single O-D pair, numerical results show that travel demand levels will remarkably influence the total system costs under different policies. The effects of average carpooling occupancy and mode choice parameters on travelers' choice behavior are analyzed. Finally, a tri-modal network with nineteen links is used to illustrate that the system could be more efficient when different EBLs policies are adopted on different links.