Mobility services

Does real-time transit information reduce waiting time? An empirical analysis

New paper: Liu, L. and Miller, H.J. (2020) “Does real-time transit information reduce waiting time? An empirical analysis,” Transportation Research A, 141, 167-179.

Highlights

  • Public transit agencies publish real time information for use in mobile apps
  • We benchmark several strategies using empirical transit system performance data.
  • Overall, real time information does not outperform simply following schedule.
  • Real time information can reduce waiting time for some users based on location.
  • Including a time buffer improves the greedy approach used by popular apps.

Abstract

A claimed benefit of real-time information (RTI) apps in public transit systems is the reduction of waiting time by allowing passengers to appropriately time their arrivals at transit stops. Although previous research investigated the overall impact of RTI on waiting time, few studies examine the mechanisms underlying these claims, and variations in its effectiveness over time and space. In this paper, we theorize and validate the sources of RTI-based users’ waiting time penalties: reclaimed delay (bus drivers compensating for being behind schedule) and discontinuity delay (an artifact of the update frequency of RTI). We compare two RTI-based strategies – the greedy strategy used by popular trip planning apps and a prudent strategy with an insurance buffer – with non-RTI benchmarks of arbitrary arrival and following the schedule. Using real-time bus location data from a medium-sized US city, we calculate the empirical waiting times and risk of missing a bus for each trip planning strategy. We find that the best RTI strategy, a prudent tactic with an optimized insurance time buffer, performs roughly the same as the simple, follow-the-schedule tactic that does not use RTI. However, relative performance varies over time and space. Moreover, the greedy tactic in common transit apps is the worst strategy, even worse than showing up at a bus stop arbitrarily. These results suggest limitations on claims that RTI reduces public transit waiting times.

Media

Movement analytics for sustainable mobility

New paper: Miller, H.J. (2020) “Movement analytics for sustainable mobility.” Journal of Spatial Information Science, 20, 115-123.

Invited essay for 10th anniversary issue

Abstract: Mobility is central to urbanity, and urbanity is central to our common future as the world’s population crowds into urban areas. This is creating a global urban mobility crisis due to the unsustainability of our 20th century transportation systems for an urban world. Fortunately, the science and planning of urban mobility is transforming away from infrastructure as the solution towards a sustainable mobility paradigm that manages rather than encourages travel, diminishes mobility and accessibility inequities, and reduces the harms of mobility to people and environments. In this essay, I discuss the contributions over the past decade of movement analytics to sustainable mobility science and planning. I also highlight two major challenges to sustainable mobility that should be addressed over the next decade.

Keywords: movement analytics, mobility science, animal movement ecology, sustainable mobility, urbanity

Measuring the impacts of new public transit services on space-time accessibility

Lee, J. and Miller, H. J. (2018) “Measuring the impacts of new public transit services on space-time accessibility: An analysis of transit system redesign and new bus rapid transit in Columbus, Ohio, USA,” Applied Geography, 93, 47-63.

Highlights

  • Lack of access to opportunities contributes to poor social and health outcomes.
  • Columbus, OH introduced a transit route and schedule redesign and bus rapid transit.
  • We analyze impacts on accessibility to opportunities in a deprived neighborhood.
  • Detailed route and schedule data allow high resolution accessibility analysis.
  • The new bus rapid transit has a much greater impact on accessibility

Abstract

The absence of effective access to opportunities and services is a key contributor to poor socio-economic and health outcomes in underserved neighborhoods in many cities. The city of Columbus, Ohio, USA is attempting to enhance residents’ accessibility by providing new public transit services. These new services include a major Transit System Redesign (TSR) of the conventional bus network and the introduction of a new bus rapid transit, named CMAX. Using a high-resolution space-time accessibility measure, we analyze whether these new public transit services will change residents’ accessibility to job and healthcare in an underserved neighborhood of Columbus. Also, we assess whether enhancing the CMAX service to reduce delays (e.g., reserved lane, off-board payment system) will improve accessibility. The high-resolution space-time accessibility measure in this study uses published public transit schedules via the General Transit Feed Specification (GTFS). We use multiple departure times during a day to account for the temporal fluctuations of accessibility based on the transit schedule changes. We also consider the operating hours of job opportunities and healthcare services. Results suggest that the TSR yields ambiguous benefits for accessibility to jobs and healthcare. However, the new CMAX service and its potential upgrades lead to a substantial increase in both job and healthcare accessibility. The results can be used for city officials and urban planners to evaluate the effectiveness of public transit innovations in improving accessibility.

Keywords: Transportation; Space-time accessibility; Public transit; Bus rapid transit; Jobs; Healthcare