Mass Transit

Passenger-Miles per Gallon

Passenger-miles per gallon (pmpg) is a metric for comparing mass transit and rideshare with typical passenger vehicle travel. Transportation system efficiency increases as the number of passengers increases or as the vehicle fuel economy increases for each transportation mode.

Vehicle mpg* Passengers pmpg
Car – national average 24 1.5 36
Car – high occupancy 24 5 120
Pickup Truck – national average 17.4 1.8 31.3
Pickup Truck – high occupancy 17.4 6 104.4
Transit Bus – national average** 3.3 9.1 30
Transit Bus – high ridership 3.3 40 132
Transit Train – national average** 2 25.8 51.6
Transit Train – high ridership 2 100 200

* All fuel converted to gallons of gasoline on an energy content basis. For trains, most of this fuel is electricity.

** National average ridership numbers are from table 2.13 of the Transportation Energy Data Book.

Mass transit in the United States includes buses, bus rapid transit, trolleys, rail, and ferries. Transit buses are particularly well-suited for alternative fuels, and more than 40% run on these lower-emissions, cost-saving options. Since mass transit vehicles can carry more passengers, they have the potential to achieve a higher passenger-mile per gallon.

Ridership determines the quality and impact of mass transit. Higher ridership leads to increased service frequency and efficiency through reduction in vehicle miles traveled (VMT) and fuel used by private vehicles. Vehicle fleet managers, corporate decision makers, and public transportation planners can use the following strategies to build strong ridership.


Dedicated or “bus rapid transit” lanes and the use of high occupancy vehicle (HOV) lanes often make mass transit commutes the quickest option. Effective mass transit is also more convenient when people find it predictable. Mass transit providers can make their services more predictable by publishing and sticking to schedules. Updating schedules often and providing them in mobile applications such as Google Maps and other formats riders can access easily also increases predictability. Some mass transit providers use geotracking systems such as NextBus to help riders track schedules and delays. Mass transit providers can also make their services more convenient by making payment easier and helping passengers link multiple transportation modes. Some transit agencies offer mobile ticketing apps or pre-loaded transit cards. In some cases, these are interoperable with bike-sharing systems or other mobility services. Making bicycle storage available on buses or at transit stations can also enable travelers to transfer transportation modes easily.


Employee passes and transit subsidies are effective incentives for corporate decision makers to build mass transit ridership, conserve fuel, and reduce VMT. Employers with mass transit incentives can gain recognition for environmentally beneficial practices and may save money by reducing transportation and parking costs. Employer compensation for transit may have tax benefits. Learn more about such commuting benefits from the U.S. Internal Revenue Service.


Switching to cleaner alternative fuel or electrified vehicles can project an image of a modern, environmentally conscious organization or municipality while making riders feel good about mass transit. Likewise, clean, well-lit vehicles and signage are more attractive to riders. Safety practices and cleanliness standards also help increase mass transit's reputation and ridership. Offering Wi-Fi is a way that many transit agencies have shifted the perception of buses towards a high-tech, professional means of commuting. Advertisement campaigns have also proved effective at improving public transit reputation and therefore increasing ridership.


Many potential riders are not familiar enough with available public transit services to choose mass transit over other transportation modes. Advertising and promotional events can help raise awareness and increase ridership. For example, the Virginia Department of Rail and Public Transportation's Try Transit Week challenges people to experience the benefits of mass transit.

More Information

Find more information and resources on mass transit from the American Public Transportation Association and the U.S. Department of Transportation Federal Transit Administration.