Real-time information

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The San Francisco Municipal Transportation Agency (SFMTA) offers real time arrival information on its train platforms. Photo by Flickr user AgentAkit.


Real-time information, broadly defined, means any information available to transit providers or customers about the current status of vehicles, including approximate locations and predictive arrival times. Most real-time information relies on automatic vehicle location (AVL) and Global Positioning Systems (GPS) in order to estimate approximate arrival times for passengers and transit system operators. Passengers access real-time arrival and departure information through dynamic signs at stops and stations, or through the Internet at home or on smartphones. As smartphones become more prevalent, they have made access to third-party scheduling information and apps highly accessible for passengers.[1]


Mobile technology

Because cellular phones and smartphones are so prevalent today, they can be very useful for disseminating real-time transit information. Mobile phones allow passengers to use SMS (or Short Message Service) to access schedule and real-time information via text message. This is a two-way method of communicating wherein the passenger can send a text message to an agency, usually with a code for the stop they want information about. The agency then automatically sends a response with the next bus’ arrival times. These services do not necessarily always use real-time information, instead responding with the next scheduled bus arrival time. However, real time information makes texting more useful to customers.

Dynamic messaging signs

These signs at stops and stations tell passengers when the next transit vehicle will arrive and can warn them if a bus or train is delayed. They are also the most common method for agencies to communicate real-time information to passengers. These can be expensive to implement because of the costs of installation, maintenance, and electricity for operation.[2]

On-board annunciators

Real-time information on-board buses and trains can include automated announcements of next stops and upcoming transfer points. This feature also adds to ADA compliance and relieves drivers from this obligation.[3]

Vehicle occupancy information

Agencies can combine real-time vehicle location data with on-board automated fare collection (AFC) and/or automated passenger counter data to provide an estimate of how crowded a bus or train is, allowing customers to evaluate whether to wait for a vehicle that's likely to be full (and if the next vehicle is too full, whether there will be another one soon after). Transit agencies in Seoul[4], Singapore[5], and Sydney[6] offer this information to their bus riders.

Benefits and Costs to Agencies

Using real-time technology can benefit agencies by improving safety and security, and has been demonstrated to increase customer satisfaction and perceptions of the transit agency. Agencies also benefit from these systems because they reduce the staff time needed to monitor for schedule adherence.

The costs of implementing these systems varies widely by the size of the agency, type of system, and which amenities the agency chooses to use. Implementing a real-time system also has costs. There are financial costs, which can vary widely depending on the technology, as well as time and staff costs associated with training and maintaining real-time technologies. Sometimes the existing information technology infrastructure and staff are not sufficient, so they must be bolstered. Finally, as mobile technology is constantly changing, it is difficult for transit agencies and even technology developers to keep abreast of changes and to create mobile applications that will work for all versions of the wide variety of platforms available for passengers’ mobile devices.[2]

Benefits to Riders

Having access to real-time information reduces passengers’ anxiety during wait time. It also reduces time spent waiting when passengers can learn about a delayed bus or other problem prior to arriving at a stop or station. This way, if buses are delayed passengers can make informed decisions about taking alternative routes or modes. After implementing AVL systems, combined with improving real-time information for customers, several agencies saw steep declines in customer complaints.[1]


Transit agencies that want to avoid the expense and risk of building a proprietary system to convey real-time information may work with vendors or produce data using established standards. See for a full list of real-time implementation applications.

  • General Transit Feed Specification-Real Time Format (GTFS-RT) [1]: Developed by Google as an extension to General Transit Feed Specification (GTFS) and released via Creative Commons in 2011, GTFS-RT is a software-agnostic standard that allows public transportation agencies to provide realtime updates about their fleet to the public vis-a-vis application developers and Google Maps. The GTFS-RT standard allows transit operators to provide the following:
  • Trip Updates - delays, cancellations, changed routes
  • Service alerts - stop moved, unforeseen events affecting a station, route or the entire network
  • Vehicle positions - information about the vehicles including location and congestion level
Agencies do not pay Google to use the format display the data on Google Products. The GTFS-realtime specification is a free alternative to for agencies that currently produce or plan to produce real-time arrival data and route or stop specific service alerts. More information is available from Google.
  • is a product offered by Cubic, a multi-national company with a software suite targeted to transit operators. NextBus offers a full-service solution, from GPS installation on vehicles, to communications with users via a desktop and mobile web site. NextBus is the market leader, with more than a dozen transit agencies as customers. More information about their products is available from the company. This section is provided for informational purposes only and is not an endorsement to purchase the Nextbus product. See TransitWiki:General_disclaimer#Commercial Products and Services Appearing on TransitWiki.
  • The OneBusAway Project is a free open-source software stack that seeks to make it easy for transit operators to build and maintain mobile applications which disseminate predictive real time arrival information. Originally started by a University of Washington Ph.D student named Brian Ferris, the OneBusAway software stack is the foundation for mobile applications maintained by MARTA, Hillsborough Transit in Tampa, Puget Sound, and the New York MTA. To build an application using OneBusAway, transit agencies do not require AVL equipment. [2].


  1. 1.0 1.1 National Center for Transit Research at the Center for Urban Transportation Research, University of South Florida.“Enhancing the Rider Experience: The Impact of Real-Time Information On Transit Ridership.” 2005.
  2. 2.0 2.1 Transit Cooperative Research Program. “Synthesis 91: Use and Deployment of Mobile Device Technology for Real-Time Transit Information.” 2011.
  3. Transit Cooperative Research Program. "TCRP Research Results Digest 5: Electronic On-Vehicle Passenger Information Displays (Visual and Audible)." 1995.
  4. Karlen, Leif. Innovative Governance of Large Urban Systems, "Case study: Displaying real-time bus occupancy levels in Seoul, South Korea". 2017.
  5. Land Transport Authority, "Enhanced Real-Time Bus Information At Your Fingertips". 2015.
  6. Reilly, Claire. CNET, "Real-time Opal data now lets you track how full your bus is". 2016

Additional Reading

Transit Cooperative Research Program. “Synthesis 91: Use and Deployment of Mobile Device Technology for Real-Time Transit Information.” 2011.

This recent synthesis, sponsored by the Federal Transit Administration, includes a literature review and survey of transit providers, with a specific focus on the underlying technology necessary for delivering real-time information to passengers using mobile phones. Survey respondents reported that automatic vehicle location is the most commonly used technology for delivering real-time information and many agencies use third-party developers to develop applications for delivering this information to passengers.

Transit Cooperative Research Program. “TCRP Synthesis 48: Real-Time Bus Arrival Information Systems." 2003.

This report, also sponsored by the Federal Transit Administration, describes the basics of how real-time information systems work and uses several case studies to demonstrate common agency experiences when using them on bus systems. It is a comprehensive document outlining broad system benefits and costs, customer reactions to the changes, and a literature review. This synthesis evaluates several case studies, including San Luis Obispo’s transit system, which uses a real-time information system that utilizes dynamic messaging signs. The system was developed by the California State Polytechnic University and was fully deployed in 2001.

Transit Cooperative Research Program. “TCRP Report 92: Strategies for Improved Traveler Information.” 2003.

This report updates previous reports on traveler information and includes a literature review of a variety of other reports on the same topic. It also examines the possibiliies for transit to take lessons from other industries, such as the airline or parcel delivery industries, in providing information to customers through the internet. The report was sponsored by the Federal Transit Administration.