Using public transportation instead of driving could save commuters an average of $10,502 a year, according to the American Public Transportation Association.
Commuters in Washington could save $9,700 annually, while in Baltimore the average savings is $9,939, according to a monthly report released by the public transport advocates.
The study is based on a national average gas price of $3.29 per gallon and the national unreserved monthly parking rate.
Maryland Transit Administration spokesman Joe Sviatko said he was not surprised by the findings.
"It's good for people to know that there is value in mass transit," he said. "It lets people in Maryland know that if they take a look at mass transit there might be some substantial savings to their monthly budget."
Frederick-area commuters heading to Washington commonly take advantage of the MARC train. A monthly pass from Frederick to the capital costs $175. For $108 more, commuters can purchase a Transit Link card to ride Metrorail and Metrobuses, which comes to a yearly base commuting cost of $3,396.
The same commute in a car getting 20 miles per gallon would cost about $5,419 per year, according to publictransportation.org's fuel-savings calculator. That estimate assumes wear on the car and a $3.44 per gallon gas price, the average in Frederick according to Gas Price Watch. It does not include parking fees, which can be high in Washington.
Frostburg State University professor Henry Bullamore said that if drivers take into account all of the costs associated with car ownership, including insurance and maintenance, they could see big savings by using public transportation.
However, most commuters do not consider all of their expenses and instead focus on the cost of gas, he said.
A commuter would not save $10,000 simply by using transit more often, Bullamore said. "I bet you could get that kind of number by giving up a car."
Going without a car would be difficult for many people, Bullamore acknowledged, because many nonurban areas are inaccessible by public transportation and many drivers like the freedom to commute on their own schedule.
AAA Mid-Atlantic spokeswoman Christine Delise said the $10,000 savings estimate seemed reasonable for long-distance commuters.
"The savings potential is not surprising when you factor in the costs associated with car ownership and commuting, especially for those workers who have a long daily drive," she said.
The Maryland Automobile Dealers Association president Peter Kitzmiller was more skeptical.
"I don't know how you would come to that number," he said.
Kitzmiller said that Maryland needs both public transportation and automobiles, and he emphasized that taxes on vehicle purchases and gas subsidize public transit.
"If you actually had to pay what it costs to operate (public transportation systems), fares would be much higher," he said.
The Maryland Department of Transportation is funded by Maryland's Transportation Trust Fund, which consists of revenue from motor fuel taxes, titling taxes, motor vehicle fees and federal aid. It also includes some corporate income taxes, sales and use taxes, transit fees, and bond proceeds.