Is Uber Really Helpful? Car Services, Transit and the Use of Urban Space
Nominated for The Planning for Sustainable Land Use and Transport Award
Arnd Bätzner, University of St.Gallen
How do new modes affect transport in urban contexts, based on their use of space? Looking at current and new modes incl. autonomous cars we find that a higher use 1-pax vehicles instead of mass transit is detrimental to the overall efficiency.
Current discussions about Transport Network Companies (TNCs) generally revolve about their degree of compliance with existing policies, their effect on the taxi industry and operational issues such as safety considerations. What generally remains unquestioned are spatial aspects of large-scale TNC operations in dense urban environments: Is it desirable to have more urban transport switched to vehicles that carry a single person, but still occupy a significant part of available urban roadway space?
To formulate and analyse the problem, a very simple model of the use of urban space by different modes resp. different passenger carrying vehicles is proposed. Then, aspects of roadspace management, congestion levels, and associated drops in overall travel speeds are discussed, as is the problem of one users' modal choices' probability of affecting other users' options and quality of travel (availability, reliability, speed). Also, questions of modal substitution are discussed: What happens if trips that would have previously been made by transit and walking are now taken using Uber, Lyft or Sidecar? How does this change when trips on TNC vehicles are shared by several passengers?
Besides passengers' time, space is the most limited asset in dense urban contexts. The goal of the paper is not to propose an elaborate mathematical model, but to highlight functional dependencies and needs for detailed scientific investigation and public discussion. Thus, it deliberately chooses a broad, holstic approach in investigating the contribution to local mobility, to efficiency and suitability of passenger transport modes in an urban context according to their use of space. It includes both scheduled and on-demand services, covering private cars, taxis, TNCs, ride sharing, car sharing and transit. Especially, TNCs' contribution to urban mobility is considered from a different perspective than in current mainstream discussions. Findings include the insight that a significantly higher use of dedicated per-person vehicles instead of mass transit is detrimental to the overall efficiency above a certain grade of roadspace occupancy, highlighting the fact that TNCs can under certain conditions complement, but not replace transit in dense urban contexts. A lookout section discusses to what extent the findings are valid for a soon-to-expect scenario of on-demand transport largely switching to autonomous cars acting as taxis.
Findings also raise new aspects of the question of limiting licenses/medaillons for taxi-like operations within a given parameter: While present limitations' historic justifications are generally based on market and competition issues, the spatial consequences of a too large number of for-hire vehicles operating at the same time within a given parameter provides a foundation for future discussions on medaillon limitations, static or possibly dynamic in time, valid for both human-operated and self-driving vehicles.
Association for European Transport