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Maintenance Management Systems
Fact Sheet: Transit Overview

Technology Overview

Use Maintenance Management Systems to:

  • Alert operations managers of underperforming vehicles and parts
  • Manage maintenance parts inventory
  • Maintain and produce maintenance records
  • Monitor and manage warranties
  • Diagnose vehicle problems remotely

On average, transit operators spend about one-fourth of their operating budgets on vehicle maintenance. With the use of new monitoring technologies paired with intelligent transportation systems (ITS) systems such as automatic vehicle location (AVL) or computer-aided dispatch (CAD), transit operators can build maintenance management systems (MMS) to monitor everything from fuel and other fluid levels to engine temperature. They can also alert operators and dispatchers of the failure of a transit vehicle’s mechanical component, such as an out-of-tolerance reading from the engine or the exhaust system. Advanced MMS can capture vehicle-operating conditions, such as temperature, pressures, and voltages, to support trend analysis for condition-based maintenance and to predict when parts might fail. MMS can help managers improve the effectiveness and efficiency of maintenance operations and ensure the use of the most reliable transit vehicles.

Maintenance management systems are also known as vehicle component monitoring, automatic vehicle monitoring, and maintenance tracking systems. MMS software creates a database of information on a transit agency’s maintenance options. These systems can be used to help maintenance workers do their work more effeciently and effectively. They also help management make informed decisions regarding maintenance versus replacement of transit vehicles to optimize the allocation of funds.

Common Combinations

Maintenance and Repair

a black and white illustration of a bus with labeled parts of the bus shown

GIS Components

AVL or CAD systems can be used in conjunction with maintenance management systems to pinpoint vehicles that are in need of repair or are underperforming. Such prevent ative maintenance allows systems to run more smoothly. To enable transmittal of maintenance data, a transit agency will need to integrate the MMS on each transit vehicle with:

  1. a wireless connection to transfer real-time diagnostic information to a garage’s central computer; or
  2. a direct cable link to download the diagnostic information at the garage during vehicle servicing.

Systems and Service Planning

Maintenance Record System at Chicago Transit Authority

Maintenance Record System at Chicago Transit Authority

MMS can be used to collect data about a vehicle’s components such as the brakes, electrical system, and heating, ventilation, and air conditioning (HVAC) and to report all the information to the central MMS software, where it is stored for further use and analysis. MMSs are typically used to record data about equipment and property, including maintenance activities, specifications, purchase date, expected lifetime, warranty information, service contracts, service history, spare parts and anything else that might be of help to management or maintenance workers. Work orders are created for maintenance crews and the MMS software is used to keep track of inspections, performance metrics and equipment breakdowns. MMS software can create status reports, summaries of maintenance activities, and an inventory of equipment and spare parts.

Real-Time Operations

If an operational transit vehicle relays information to the MMS software that it has received an out-of-tolerance warning, then the central control dispatcher may decide to continue the route using the current vehicle, replace the vehicle in the field, or reroute the vehicle along a more “tolerant” path (e.g., a flatter route for braking issues, along a shadier or cooler route for HVAC problems). The dispatch operator can determine these routing or replacement options by utilizing her CAD and AVL systems and transmitting the decision made to the transit vehicle operator via radio.

Factors to Consider

Maintenance management systems (MMS) should be considered by officials operating medium and large fixed-route bus, demand response and human service transit agencies. MMS is very useful for all transit agencies with moderate-sized fleets that perform in-house maintenance. The remote diagnostic features of a MMS is probably not necessary for most agencies. Most MMS functions are intended to be utilized within a garage environment, including monitoring life cycle vehicle costs and tracking inventories. The MMS for fixed-route bus transit agencies should be developed as part of their asset management system. All rail transit agencies should examine the remote diagnostics capabilities of the vehicle component monitoring system, but also ensure that they include a manual override of any automatic shut-down commands.

Before installing MMS in a fleet of vehicles, planning, implementation, and integration should be considered so the technology can be used to optimize the fleet’s performance.


A Los Angeles County MTA vehicle under repair in a maintenance facility

Los Angeles County MTA vehicle under repair in a maintenance facility

  • Develop a well-structured procurement plan and performance-oriented requirements.
  • Ensure adequate data storage and analysis capacity.
  • Avoid proprietary interfaces between vehicle and dispatch-center components.
  • Choose technologies with open standards, and develop detailed documentation.
  • Ensure scalability in case there are changes in fleet size.
  • Identify vehicle capacity for additional wiring and examine how that would impact available passenger space.


  • Train drivers and dispatchers.
  • Hire new staff as needed to analyze data collected from vehicles.
  • Test and troubleshoot to ensure that data are being gathered correctly.
  • Update other technologies, such as global positioning systems (GPS) or wireless communications, as needed.


  • Integrate MMS with AVL or CAD to track trends or changes in a vehicle’s status, including fluid levels and engine temperature.
  • Consider integration of MMS with other ITS capabilities and functions, including planning and scheduling systems.

Benefits and Costs


Preventative Maintenance

Reduced in-service breakdowns and improved fleet capability will ensure that transit systems run more smoothly. Implementing an MMS can help a transit agency save money by replacing assets before they fail and reducing unscheduled maintenance. An MMS is essential for benchmarking preventative maintenance performance and for determining if changes made to the maintenance program are having a positive effect.

Centralized Data

The Southeast Pennsylvania Regional Transportation Authority (SEPTA) integrated reference manuals, purchasing, inventory control, and work-order functions into its MMS, centralizing information on vehicles at one accessible location.

Trend Analysis

Integrated systems can capture conditions such as temperatures, pressures, and fluid levels and can analyze trends to predict the need for parts and service.



A basic MMS can be installed for as little as $15,000 per garage. A more sophisticated MMS with centralized MMS software integrated with an asset management system is more expensive to deploy. This kind of integrated system includes onboard mechanical monitoring sensors in each transit vehicle that are linked to the communications system for real-time transmittal of the data collected to the central MMS software. Such a system cost one multi-modal transit agency more than $2 million to deploy.

A Los Angeles County MTA vehicle under repair in a maintenance facility

Florida bus maintenance facility

Based on existing systems, the mean cost of just the central MMS software is between $100,000 and $250.000. The onboard transit vehicle sensor equipment and integration of this equipment to the central MMS software can vary, costing between $10,000 and $20,000 per transit vehicle.

Operations and Maintenance (O&M)

  • Yearly, O&M costs for onboard equipment average 2 percent of the original capital cost.
  • A transit system typically spends 25 to 27 percent of their operating budget each year on maintenance. Maintenance is divided into two categories: scheduled and unscheduled maintenance.
  • Recurring costs can include wireless communications service fees.


For an MMS to be cost-effective, fleet managers must be trained to use the information the system collects. Training of a limited number of select staff is usually included within the full deployment cost.

Agency Deployments

Agency Contact Information Number of Vehicles Context / Success of Deployment
Los Angeles County Metropolitan Transportation Authority (LAC MTA) One Gateway Plaza
Los Angeles, CA
2,472 buses
  • 100 percent of fleet equipped with onboard MMS
  • Integrated with maintenance and material management systems
  • Powertrain alarms transmitted in real time
New Jersey Transit (NJT) NJ Transit
Headquarters Building
One Penn Plaza East
Newark, NJ
200 commuter rail cars
60 electric locomotives
(also has 2,027 buses in fleet)
  • Initial deployment with Rail Operations
  • Remote diagnostics and automatic real-time failure notification on 60 electronic locomotives
  • Single-point-of-maintenance data access on all commuter railcars
Chicago Transit Authority (CTA) 567 W. Lake St.
Chicago, IL
1,781 buses
1,200 rail cars
  • 100 percent of fleet equipped with onboard MMS
  • Powertrain alarms transmitted in real time
  • Voice annunciation system used to report health status of ITS components
Southeastern Pennsylvania Regional Transit Authority (SEPTA) 1234 Market St.
Philadelphia, PA
1,388 buses
1,190 rail cars
MMIS—Maintenance Management Information System—incorporates vehicle maintenance with purchasing and inventory control
Pierce Transit (Tacoma area) 3701 96th St. SW
(P.O. Box 99070)
Lakewood, WA 98496
132 buses (total fleet—270 buses) Comprehensive maintenance data collection, analysis, and reporting system

Additional Resources on GIS and Data Management (and ITS)


Jonathan Walker, P.E., Ph.D.
Chief Policy, Architecture, and Knowledge Transfer, ITS Joint Program Office
U.S. Department of Transportation
(202) 366-2199

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