MARC train at Odenton. Photo by skabat169 on Flickr.

Money from higher state gas taxes would enable MARC to begin realizing its great potential to enhance the mobility of Marylanders and Washing­tonians, while fostering smarter land use and cutting pollution.

With an average daily ridership of 31,300 on MARC’s three lines, MARC train service is great for what it is.

The Penn Line, running between Union Station, Baltimore, and Perryville, two ways, all day and into the night, accounts for over half of MARC ridership: not surprising given the greater level of service. But, as Penn Line commuters who routinely experience standing-room-only trains know, even the current level of service is insufficient to meet existing demand.

The Camden and Brunswick Lines offer even less service. The Camden Line’s 18 trains between Union Station and Baltimore accommodate reverse commuting, but only during limited hours, and with an average headway of almost 50 minutes. The Brunswick Line’s 18 daily trains, between Union Station, Frederick, and Martinsburg, are useful only for an eastward commute during normal working hours.

None of the three lines offers weekend or holiday service, although Amtrak does serve a few Penn Line stops.

Such limited service is not enough to give people a meaningful alternative to driving. And it is surely not enough to support Governor O’Malley’s designation of five MARC stations as priority sites for transit-oriented development (TOD). Would TOD at Laurel and Savage, on the Camden Line, actually reduce energy use by TOD’s potential of a third to a half? Would TOD at Aberdeen, with 12 MARC trains per day, be a meaningful contributor to Maryland’s goal of reducing greenhouse gas emissions by 25% by 2020?

To address inadequate service, the Maryland Transit Administration (MTA) released the MARC Growth and Investment Plan (MGIP) in September of 2007. Full implementation of the plan would triple passenger capacity by 2035. It would also reduce headways to 15 minutes on the Penn Line and 20 minutes on the Camden and Brunswick Line, provide all-day, two-way service on all three lines, and add weekend service as well. The estimated capital investment cost for the whole plan is $3.9 billion.

$3.9 billion over 27 years sounds like a lot of money. But compare it to the $2.5 billion cost of the Wilson Bridge replacement, the projected $2.6 billion cost of the disastrous Maryland Intercounty Connector, and the up to $4.6 billion cost of the absurd proposed widening of I-270 in Montgomery and Frederick Counties.

Putting money towards the MGIP instead would be far more cost-effective, making rail a viable choice in the dense I-95 and I-270 corridors. It would link residents in eastern Montgomery and Prince George’s Counties to the jobs in the western parts of Montgomery County and enable the development of real TOD around MARC train stations. Further, it would reduce traffic congestion, dependence on foreign oil, air and water pollution, and our region’s contribution to anthropogenic global climate change.

Unluckily for all of us, however, the MTA proposed the plan just in time for the recession. As a result, MARC service was actually cut. And although a few more trains were recently added to the Penn Line, there has been no funding of the MGIP.

Until (perhaps) now.

There is new and increasing political support for raising Maryland’s gasoline tax, which makes up a significant proportion of the revenues that go into the state’s Transportation Trust Fund. (Note that gas is exempt from the state sales tax.) Because Maryland’s gas tax has been 23.5 cents per gallon since 1992, Transportation Trust Fund revenues have not even kept up with inflation. They are now inadequate for basic maintenance of existing transportation infrastructure, let alone expansion.

In the 2011 General Assembly session, 37 Delegates sponsored a bill to add ten cents per gallon and adjust the gas tax for inflation; the Montgomery and Prince George’s County executives and the mayor of Baltimore testified in favor. Montgomery County state senators Roger Manno and Rob Garagiola also sponsored legislation, and Senate President Mike Miller was in favor of the idea. The 2012 General Assembly will surely consider gas tax legislation as well.

This is great news — but only if the money goes to useful projects. It must not be spent on building new roads, which will only increase traffic, pollution, and future maintenance costs.

Instead, much of the money must go towards maintaining existing transportation infrastructure, including mass transit, roads, and bridges. And it is crucial for the rest to go towards expanding mass transit and pedestrian and bicycle facilities, within and between Maryland’s cities and towns. Not only will this benefit everybody, it will also offset the regressive effect of the higher gas tax on the people who are least able to afford driving.

Ideally, as Senator Manno’s bill did last year, the gas tax will have earmarks for mass transit, including the MARC Growth and Investment Plan. The tax should go up as transportation infrastructure costs go up, either through annual adjustments or by switching from a per-gallon to a per-dollar levy. And, to increase political support, it will return some of the revenue to the counties to spend on their own transportation priorities.

Funding all-day, two-way, weekday and weekend MARC service through higher gas taxes will pay off with better mobility and a cleaner, healthier, and more sustainable future for the region’s residents. The alternative is more cars, more traffic, more sprawl, and more pollution. Is this really such a hard choice?