Congestion-​informed dynamic space allocation for different transport modes  

Description

Dedicated road space strategies for different modes can optimize accessibility, with a long-term goal of motivating travelers to opt for specific transport modes instead of private car, leading to reduced car demand and more efficient road space use. Among various policy measures, dedicated purpose lanes (bikes or buses) have seen wide use due to their effectiveness in reducing delays caused by traffic interactions. However, space reserved for one mode is taken from another one, which can potentially induce congestion due to local capacity reduction, e.g. in neighborhoods of infrequent usage or mode-inflexible demand, indicating that location selection plays an important role in the efficiency of space allocation strategy.

Balancing the trade-off between eco-friendly mode enhancement and general traffic performance in an optimal way is a very challenging task. Not only due to the complexity of multi-modal network traffic modeling, but also due to the competitive nature of the problem, which requires accurate prediction of travelers’ reactions concerning mode and route choices; these can be significantly influenced by any infrastructure change (such as a dedicated lanes). This optimal design problem can be addressed by assuming static traffic conditions, assuming steady-state traffic conditions, with link travel times being calculated by empirical relationships on the basis of standard delay functions. However, dynamic congestion propagation due to spillback effects of queues in city-scale networks should be considered.