Competition between shared autonomous vehicles and public transit: A case study in Singapore

Emerging autonomous vehicles (AV) can either supplement the public transportation (PT) system or compete with it. This study examines the competitive perspective where both AV and PT operators are profit-oriented with dynamic adjustable supply strategies under five regulatory structures regarding whether the AV operator is allowed to change the fleet size and whether the PT operator is allowed to adjust headway. Four out of the five scenarios are constrained competition while the other one focuses on unconstrained competition to find the Nash Equilibrium. We evaluate the competition process as well as the system performance from the standpoints of four stakeholders -- the AV operator, the PT operator, passengers, and the transport authority. We also examine the impact of PT subsidies on the competition results including both demand-based and supply-based subsidies. A heuristic algorithm is proposed to update supply strategies for AV and PT based on the operators' historical actions and profits. An agent-based simulation model is implemented in the first-mile scenario in Tampines, Singapore. We find that the competition can result in higher profits and higher system efficiency for both operators compared to the status quo. After the supply updates, the PT services are spatially concentrated to shorter routes feeding directly to the subway station and temporally concentrated to peak hours. On average, the competition reduces the travel time of passengers but increases their travel costs. Nonetheless, the generalized travel cost is reduced when incorporating the value of time. With respect to the system efficiency, the bus supply adjustment increases the average vehicle load and reduces the total vehicle kilometer traveled measured by the passenger car equivalent (PCE), while the AV supply adjustment does the opposite

Coordination between node, place, and ridership: Comparing three transit operators in Tokyo

Balancing network accessibility (node value) and station-area land use (place value) has been an important research topic for transit-oriented development, but little was known about how node and place value should coordinate with ridership. Using Tokyo as a case study, we develop a node-place-ridership model to evaluate coordination between these three facets and compare different transit operators, namely subway in central area, private railway in suburban area, and Japan Railway (JR) in both central and suburban area. An indicator framework is established to measure the node value by accessible opportunities, network centrality, and train service, and measure the place value by density, design, and diversity. Using open-source urban data, we generate a series of node and place indicators for each station and develop a composite node value index and place value index with information entropy weighting. The results show that node value and place value have positive impacts on ridership and node value’s impact is five times higher than place value. Stations balanced between node and place value can be uncoordinated with ridership, while stations unbalanced between node and place value can coordinate with ridership. JR has better node-place balance and ridership coordination than subway and private railway. Several implications are drawn for ridership coordination with node and place value, including planning for a more mixed urban structure and using through trains to connect central and suburban transit networks. The results of this study would inform transport planners of better organizing transit network, land use, and ridership in urban space

Impact of Transit-Oriented Development on Residential Property Values around Urban Rail Stations

Few previous studies have linked transit-oriented development (TOD) patterns and property values at the station level in the Chinese context. Using Shanghai as a case study, we obtained 21,094 transaction records within the 800 m radius catchment areas of 280 urban rail stations from a local property agency. A performance-based TOD indicator framework was established to capture built-environment features for density, diversity, and design dimensions. Using open-source geospatial data, we generated a series of TOD indicators for each station catchment area and further developed a composite TOD index with information entropy weighting. The results of multilevel regression models showed that within urban rail station catchment areas, residential properties with higher TOD levels were positively associated with higher value. In addition, increasing pedestrian and bike accessibility and integrating diversified urban functions around stations could create more value for nearby residential properties

Competition between shared autonomous vehicles and public transit: A case study in Singapore

Emerging autonomous vehicles (AV) can either supplement the public transportation (PT) system or compete with it. This study examines the competitive perspective where both AV and PT operators are profit-oriented with dynamic adjustable supply strategies under five regulatory structures regarding whether the AV operator is allowed to change the fleet size and whether the PT operator is allowed to adjust headway. Four out of the five scenarios are constrained competition while the other one focuses on unconstrained competition to find the Nash Equilibrium. We evaluate the competition process as well as the system performance from the standpoints of four stakeholders—the AV operator, the PT operator, passengers, and the transport authority. We also examine the impact of PT subsidies on the competition results including both demand-based and supply-based subsidies. A heuristic algorithm is proposed to update supply strategies for AV and PT based on the operators’ historical actions and profits. An agent-based simulation model is implemented in the first-mile scenario in Tampines, Singapore. We find that the competition can result in higher profits and higher system efficiency for both operators compared to the status quo. After the supply updates, the PT services are spatially concentrated to shorter routes feeding directly to the subway station and temporally concentrated to peak hours. On average, the competition reduces the travel time of passengers but increases their travel costs. Nonetheless, the generalized travel cost is reduced when incorporating the value of time. With respect to the system efficiency, the bus supply adjustment increases the average vehicle load and reduces the total vehicle kilometers traveled measured by the passenger car equivalent (PCE), while the AV supply adjustment does the opposite. The results suggest that PT should be allowed to optimize its supply strategies under specific operation goals and constraints, and AV operations should be regulated to reduce their system impacts, including potentially limiting the number of licenses, operation time, and service areas, which makes AV operate in a manner more complementary to the PT system. Providing subsidies to PT results in higher PT supply, profit, and market share, lower AV supply, profit, and market share, and increased passenger’s generalized cost and total system PCE

E-scooter sharing to serve short-distance transit trips: A Singapore case

E-scooter sharing provides a last-mile solution to complement transit services, but less was known about its effectiveness in serving short-distance transit trips. We investigate the potential of using e-scooter sharing to replace short-distance transit trips of excessive indirectness, multiple transfers, and long access-egress walking. First, we conducted a stated preference survey on e-scooter users in the Central Area of Singapore and estimated mixed logit models to examine factors influencing the choice of e-scooters and transit. We then calculated the number of transit trips that can be replaced by e-scooters. Second, we analyzed the decision of e-scooter companies in terms of the trade-offs between serving more e-scooter trips and making more revenue under varying fares. The results show that fare, MRT transfer, and MRT access-egress walking distance have significantly negative impacts on mode utilities with random tastes among respondents. Male, young and high-income groups are more heterogeneous in e-scooter preferences compared with other groups. The loss of mode share can be nearly 17% if maximizing the revenue. We classify trade-off situations into five categories and provide suggestions of how to balance between mode share and revenue for each category. Several implications are drawn for better harnessing and regulating this new mobility service, including where to deploy e-scooters to satisfy the demand unmet by the transit and how to reach a proper balance between private operators and public welfare