Public Transportation

Passenger-Miles per Gallon

Passenger-miles per gallon (pmpg) is a metric for comparing passenger vehicle travel across modes. 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 24.2 1.5 36.3
Car – high occupancy 24.2 5 121
Pickup Truck – national average 17.5 1.8 31.5
Pickup Truck – high occupancy 17.5 6 105
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.

Public transportation in the United States includes buses, bus rapid transit, trolleys, rail, and ferries. Transit buses are particularly well-suited for alternative fuels, and nearly 60% run on these lower-emissions, cost-saving options. Since transit buses can carry more passengers, they have the potential to achieve a higher passenger-mile per gallon.

Ridership determines the quality and impact of public transportation. Higher ridership can lead to increased service frequency and efficiency through reduction in vehicle miles traveled (VMT) and fuel used by private vehicles. Corporate decision makers and transportation planners can use the following strategies to help build strong ridership.


Making public transportation convenient can be a good way for transportation planners to boost ridership. Dedicated or “bus rapid transit” lanes and the use of high occupancy vehicle (HOV) lanes can reduce travel time for public transportation. Effective public transportation is also more convenient when people find it predictable. Public transportation providers can make their services more predictable by publishing schedules and communicating status updates. Updating service status often, and providing it via easily accessible mobile applications such as Google Maps, also increases predictability. Some public transportation providers use geotracking systems such as NextBus to help riders track schedules and delays. Public transportation providers can also make their services more convenient by offering flexible payment options such as app-based services that integrate payment for a range of mobility options, such as micromobility and ride hailing, as part of a common payment platform.

Another way to facilitate public transportation ridership is to help people complete the first or last leg of their trip and get to the transit stop. Helping passengers link multiple transportation modes is key. Some public transportation 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 or scooter storage available on buses or at transit stations can also enable travelers to move between transportation modes easily. Public transportation agencies are also forming partnerships with transportation network companies, like Uber or Lyft, and micromobility providers to improve mobility choices for customers.

Workforce Mobility

A growing number of employers are offering mobility benefits as part of an emerging trend to incentivize or otherwise support employees to explore energy-efficient commuting options. Employee mobility benefit packages may include a variety of options, such as free or subsidized transit passes, membership to micromobility systems, ridesharing coordination, flexible schedules, work-at-home options, parking payout for those who forego employer parking, on-demand microtransit vehicles, and even chauffeured, Wi-Fi-enabled luxury shuttles.

Employees may benefit from such programs through reduced commuting costs, reduced need for vehicle ownership, and the ability to reclaim time that would otherwise have been spent piloting a vehicle. Employers may benefit from being in a stronger position to recruit and retain labor talent, reduce investments for private car parking, and project an image of energy consciousness. Employee passes and transit subsidies are effective incentives for corporate decision makers to build mass transit ridership, conserve fuel, and reduce VMT. 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 public transportation. Likewise, clean, well-lit vehicles and signage are more attractive to riders. Safety practices and cleanliness standards also help increase public transportation’s reputation and ridership. Offering Wi-Fi is a way many public transportation agencies have shifted the perception of buses toward a high-tech, professional means of commuting. Advertising campaigns have also proved effective at improving public transportation’s reputation and supporting 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 invites people to experience the benefits of mass transit.

More Information

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