A Literature Review of the Passenger Impacts of Real-Time Transit Information

Abstract

Recently, it has become common practice for transit operators to provide real-time information (RTI) to passengers about the location or predicted arrival times of transit vehicles.  Accompanying this is a growing body of literature that aims to assess the impacts of RTI on transit passenger behavior and perceptions.  The objective of this research is to compile a comprehensive literature review of studies that assess the passenger impacts of RTI provision.  The results suggest that the primary behavioral changes associated with providing RTI to passengers pertain to decreased wait times, reductions in overall travel time due to changes in path choice, and increased use of transit.  RTI may also be associated with increased satisfaction with transit service and increases in the perception of safety when riding transit.  Important areas for future research were also identified, including assessing actual behavioral changes of path choice of transit riders and conducting cost-benefit analyses post implementation of RTI systems.  The primary contribution of this study is a comprehensive review of the passenger benefits of RTI, which has immediate implications for public transit operators considering implementation or expansion of RTI systems.

Keywords

Public transit; real-time information; wait times; ridership; path choice

1. Introduction and Motivation

The transit industry has benefitted from numerous technology changes over the past two decades. One example is the widespread availability of real-time information, which provides the precise position or predicted arrival time of a transit vehicle at a stop or station.  Real-time information is typically used for operations and control purposes by the transit provider, but it is increasingly distributed directly to passenger via signage at stops or stations and through web-enabled or mobile devices (Schweiger, 2011).  As this industry practice has increased, the body of literature evaluating the passenger impacts of this new information source has also grown, which presents an opportunity to synthesize and compare findings.  Synthesizing initial trends is particularly important for transit providers who want to understand the impacts of real-time information to appropriately plan service and to weigh trade-offs between investments.  Subsequently, this study aims to conduct a comprehensive literature review of studies pertaining to passenger impacts of real-time information.

2. Terminology and Theory

Real-time information refers to up-to-the-minute tracking of transit vehicles by automatic vehicle location systems or track circuit systems. Vehicle location information is sent to a central server, typically located at the transit provider, and then it is disseminated to riders, either directly or through application programming interfaces (API) used by third party software developers.

2.1 Terminology

Although real-time information (RTI), real-time transit information (RTTI), real-time passenger information (RTPI), and advanced passenger information systems (APIS) are all commonly used terms in the literature, for this paper, the term real-time information (RTI) will be used.

A few distinctions between RTI and other forms of transit information should be made. Schedules refer to the predefined location and time of vehicles published by the transit operator. When transit vehicles are running on-time, schedule information and RTI are the same, but when transit vehicles are not, RTI is a more accurate method of tracking the actual location of transit vehicles.  Furthermore, transit service alerts are notifications that report major delays, and while these are often provided to passengers in real-time as incidents occur, they can include varying levels of information. There is prior literature that focuses on the passenger impacts of alerts about major delays (e.g., Bai and Kattan, 2014); however, this is not reviewed here.

2.2 Theoretical Impacts of RTI on Passengers

When considered from the passenger perspective, RTI can impact numerous transportation decisions made by the traveler.  Theoretically, RTI could impact a person’s decision to make a trip (travel choice), the decision to take transit for that trip versus another mode (mode choice), the specific path that the person takes on transit (route choice), the stop at which the person boards a transit vehicle (boarding stop choice), and the time at which a person leaves his/her origin to arrive at that stop (departure choice).  This decision-making process provides a passenger-centric framework that is shown on the left side of Figure 1.  Although the diagram in Figure 1 is shown with a nested structure, this decision-making