The study is described in a paper titled, “E-scooter sharing to serve short-distance transit trips: A Singapore case,” published recently in Transportation Research Part A: Policy and Practice. The work was led by Zhejing Cao, PhD researcher at Tsinghua University when she was a visiting SMART FM student, and co-authored by Jinhua Zhao, SMART FM lead principal investigator and associate professor in MIT’s Department of Urban Studies and Planning; as well as Xiaohu Zhang, an assistant professor at The University of Hong Kong; and Kelman Chua and Honghai Yu from Neuron, a Singapore e-scooter sharing operator.
Having first been introduced in Singapore around 2013, the e-scooter, also known in Singapore as a type of personal mobility device, grew swiftly in popularity as an affordable and convenient mobility alternative to driving on Singapore’s often-congested roads during peak hours. The number of e-scooter users has grown rapidly, swelling to around 100,000 registered e-scooters in Singapore by November 2019.
Their popularity, however, has not been problem-free, as a number of serious and even fatal accidents have involved e-scooters and their riders colliding with pedestrians. This ultimately led to a government-mandated ban on their use on footpaths across Singapore in November 2019.
Despite the footpath ban, e-scooters are currently a legal mode of mobility on some 440 kilometers of cycling paths island-wide, and remain in widespread use in Singapore today. E-scooter sharing services have also become micro-mobility services in many cities worldwide, including Singapore, with the emergence of companies such as Telepod and Neuron. E-scooter sharing services provide a convenient micro-mobility service to the public, with rental locations situated across the island and with e-scooters that can be unlocked and paid for via a smartphone app. In addition, e-scooters are an environmentally-friendly alternative to other transportation options via reduced carbon emissions, engender improved life quality and health, and offer mobility aid to the elderly and the disabled.
Lead author Zhejing Cao acknowledges safety concerns surrounding the use of e-scooters, but also notes that they bring compelling benefits to many. “The safety concerns around e-scooter use and the safety of all road and footpath users are of utmost importance,” she says. “Nevertheless, given the numerous benefits that e-scooters bring to the mobility and transport ecosystem, we hope that our work will go some way towards helping policymakers in facilitating the safe and regulated use of e-scooters as an emerging but important micro-mobility service.”
In the Singapore Central Area (SCA), despite the high accessibility of the mass rapid transit system island-wide, the ratio of rapid transit network distance to the shortest street path can be much higher than the global average. Furthermore, 20.98 percent of rapid transit trips in SCA have at least one transfer, higher than the average transfer level in Singapore, and passengers may have to walk an average of nearly 1 kilometer to enter and exit rapid transit stations. As a result, even if the origin and destination of a trip are in close geographical proximity, the overall traveling journey may be suboptimal, and could be made more efficient.
E-scooters can provide a valuable alternative in this segment. As such, it is valuable to explore and investigate the practicality and potential of using e-scooter sharing to replace certain short-distance transit trips where alternative transit methods may not be convenient.
In this study, the researchers collaborated with Neuron to explore the potential of using e-scooter sharing to replace short-distance transit trips in the SCA. The researchers conducted a stated preference survey of e-scooter users in the SCA and estimated mixed logistic models to examine factors influencing a user’s choice of e-scooter and transit. Based on this, the number of transit trips that can be replaced by e-scooters was calculated, and the researchers then analyzed decisions made by e-scooter companies in terms of the trade-offs between serving more e-scooter trips and generating more revenue under varying fares.
The researchers found that fare, transit transfer, and transit walking distance have significant negative impacts on mode utilization, with seemingly random choices among respondents. The uncertainty is higher in predicting e-scooter usage preferences of male, young, and high-income groups. In analyzing the travel demands under different levels of transit inconvenience, the researchers discovered that a higher level of transit indirectness, more transfers, and longer access-egress walking result in a higher average probability of using e-scooters as a mode of transit.
Through analyzing e-scooter companies’ decisions, the researchers also found that the revenue losses borne by e-scooter companies can be significant if e-scooter mode share is maximized with no regard for other considerations, and vice versa.
In order to achieve a better balance between these two competing goals, the researchers found the optimal trade-off places in between two maximization extremes, thus finding the sweet spot where a small sacrifice in maximizing one goal can prevent great loss in the other.
“E-scooter sharing services have shown enormous potential to become an important component of transit systems in urban environments in Singapore and other cities worldwide,” Cao says. “Our study has highlighted the shortcomings of public transport in serving short-distance journeys in the SCA. E-scooter sharing services are able to bridge this gap and provide a convenient micro-mobility service to the public.”
Co-author Xiaohu Zhang adds, “E-scooter sharing as a new form of micro-mobility will improve the overall efficiency of urban transportation systems through enhancing last-mile connectivity as well as serving short-distance travels. It also has huge potential in the future if powered by autonomous driving technology.”
The findings of the SMART study can be used to inform operators, planners, and policymakers on how to harness and regulate this new mobility service, as well as provide suggestions on deploying shared e-scooters to satisfy demand unmet by transit, especially where transit travel involves greater indirectness, transfer, and access-egress walking distance. E-scooter supply strategies at different locations can be varied according to various socio-demographic factors that influence e-scooter preference and mode choices.
When public authorities and private operators take conflicting positions on whether to serve more individual trips or generate greater revenue, the trade-off can be gauged to achieve balance. Such possible means of mitigating disparity between the two goals and achieving balance include administrative regulations (e.g., requiring operators to serve inconvenient short transit trips at certain designated locations) or economic interventions (e.g., subsidies to operators provided by public authorities).
Jinhua Zhao adds, “Evidently, e-scooters present unique advantages and challenges for regulators and policymakers. If managed and regulated effectively, e-scooter sharing services can play an important role in the public mobility circuit, filling a gap in the short-distance transit segment that public transport is, as yet, often unable to fill.”
The research is carried out by SMART and supported by the National Research Foundation (NRF) Singapore under its Campus for Research Excellence And Technological Enterprise (CREATE) program.
FM is one of five interdisciplinary research groups in SMART. FM harnesses new technological and institutional innovations to create the next generation of urban mobility systems to increase accessibility, equity, safety, and environmental performance for the citizens and businesses of Singapore and other metropolitan areas worldwide. SMART-FM is supported by the NRF and situated in CREATE.
