Space allocation for multi-modal urban networks with ridesplitting services and public transport

The surge of Mobility on Demand (MoD) is largely attributed to advancements in mobile internet and technology. Ridesourcing platforms, among other solution services, offer convenience and flexibility when it comes to pick-up/drop-off time and location, all while keeping prices within affordable ranges. Similarly, ridesplitting renders itself as an extension to ridesourcing where platform users agree to share their rides in return for a reduced fare yet a longer travel time. Despite the numerous advantages that sharing introduced to the platform operator by reducing the fleet size necessary to serve demand levels, or to the environment by mitigating emissions, e-hailing is still overall negatively impacting traffic performance in urban spaces. This is partially due to current tendency of users to favor solo over shared rides. This paper aims to use aggregate traffic flow models to put forward a network space redistribution policy that has the potential to alleviate urban congestion by inducing modal shifts towards more efficient modes. Accordingly, we investigate the new network split that minimizes the total passenger hours traveled for all network commuters in the event where shared rides are allowed to use underutilized bus lanes. As a result, the choice to share is associated with an inevitable additional detour distance but with a lower-than-anticipated trip time compared to standard scenarios where the totality of the fleet utilizes the same network space. Results show that the impact of this strategy extends beyond the mere improvement of the total travel time of all network users to the reduction of the detour distance incurred by sharing as more users opt for ridesplitting. Moreover, this strategy decreases total network accumulation and incentivizes e-hailing platforms to lower their fleet size without much disturbing bus operations.