Mobility impact analysis under MaaS: A perspective from car owner users

"Mobility as a Service" (MaaS) seamlessly integrates multiple travel modes and has received increasing attention in recent years. However, its effectiveness in attracting private car users and reducing overall system carbon emissions remains uncertain. In order to investigate the travel mode choice difference of car owner users under the scenario with and without MaaS, this study propose a travel mode choice simulation framework under the presences of vehicle restrictions and congestion pricing. First, in the absence of traffic regulations, we model the travel mode choices of car owners in the scenarios with and without MaaS. The vehicle restrictions and congestion pricing are then modeled in the MaaS scenario. Using this simulation framework and real travel data from Beijing's MaaS platform, we further investigate the effects of user numbers, vehicle restrictions, and congestion pricing on carbon emissions, comparing the outcomes under different traffic regulations in the MaaS. Results indicate that while the adoption of combined travel modes in MaaS scenarios reduces reliance on private cars and ride-hailing services, it simultaneously leads to an increase in system carbon emissions. Therefore, this paper recommends promoting MaaS platforms in conjunction with dynamic vehicle restriction and congestion pricing policies to reduce the use of private cars and ride-hailing services. Moreover, low-carbon travel options are recommended to be prioritized, and green travel incentives is recommended to be implemented for incentivize users toward more environmentally friendly travel choices.