Northern Virginia has widened its main highways since 2012 by adding 53 miles of privately operated tolled express lanes. It is currently constructing 33 miles more. Across the river, Maryland can’t agree to build an inch.

Does that mean the Old Dominion has a more pragmatic approach, friendly to both business and drivers? Or is the Free State just more environmentally responsible and wary of letting private companies run public services?

The answer is both, and the contrast highlights a deep difference in the political climates on opposite banks of the Potomac.

It’s hard to overstate the divergence between Virginia and Maryland regarding the laying of asphalt in recent years.

In Virginia, both Democrats and Republicans have supported using public-private partnerships to widen the Capital Beltway and Interstates 95, 395 and 66.

Most drivers pay to use the express lanes. (High-occupancy vehicles travel free of charge.) That relieves traffic on the regular, non-tolled lanes.

The Virginia Department of Transportation says travel times on regular lanes on the Beltway and I-95 have improved by 7 percent to 14 percent compared to periods before the express lanes opened.

Maryland has not followed suit. Maryland Gov. Larry Hogan (R) has run into a thicket of political and community opposition to his plan to add similar lanes to Interstate 270 and the Beltway in Montgomery County.

The pushback, led by Montgomery County Executive Marc Elrich (D), also threatens Hogan’s agreement with Virginia Gov. Ralph Northam (D) to rebuild and widen the American Legion Bridge, which carries the Beltway across the Potomac between Montgomery and Fairfax counties.

In the latest development, opponents of Hogan’s plan succeeded in effectively removing it from a key regional list of long-term transportation projects. Unless the move is reversed, the toll lanes cannot secure federal environmental approval.

Elrich says he can support adding two reversible lanes to I-270, part of the Beltway and the bridge. That’s instead of the four lanes proposed by Hogan. The governor’s backers say that’s shortsighted and insufficient, partly because reversible lanes are awkward to manage and are not appropriate for the traffic flows.

The contrast between Virginia and Maryland isn’t about whether to have transit. Both states want more of that. Virginia has widened its highways while also building the Silver Line and planning a Bus Rapid Transit line along Richmond Highway (Route 1).

But Montgomery officials question the wisdom of expanding highways given the need to combat climate change. They would rather see a dramatic transformation of transportation via increased reliance on commuter rail and buses, as well as on the light-rail Purple Line currently under construction. Some want to change land-use policies to concentrate housing close to transit.

They’re right in theory, but it’s not working in practice. Proposals to expand commuter rail service on MARC’s Brunswick line, and to add express buses on Route 355 and Georgia Avenue, are moving slowly or not at all. Many neighborhoods are reluctant to increase density, for fear of worsening traffic and overcrowding schools.

The result is that Montgomery, for now, is getting neither wider roads nor dynamic development of transit-friendly communities.

The Hogan plan’s supporters include a lengthy list of chambers of commerce and construction unions. They say local Democratic elected officials care only about appealing to their most left-leaning constituents, to prevail in primaries. Republicans are barely a factor in Montgomery elections.

By contrast, Virginia elected officials of both parties have been more sympathetic to business interests. That’s partly because Republicans, until recently, were more of a force in Northern Virginia. Also, the Northern Virginia business community is better organized and more strategic about pushing its agenda.

Maryland local officials “are listening to a loud, vocal minority that they think represents the consensus of the local population,” said Emmet Tydings, chair of the Suburban Maryland Transportation Alliance. “Virginia over the last 20 years has created the critical mass of businesses, large and small, that can counterbalance this. Montgomery County has headed in the opposite direction.”

Opponents of the Hogan plan agree that the dissimilarity with Virginia is real, although they view it from the opposite perspective.

“The politics are very different,” said Stewart Schwartz, executive director of the Coalition for Smarter Growth. “If I had to narrow it down to one thing, concern about the environment and conservation issues is stronger in Maryland.”

Another complicating factor is Montgomery’s political geography. Many of its leaders have their political base in the county’s southeastern sector. It’s densely built, so there’s little room to add roads. Their core supporters want transit, bike paths and pedestrian amenities.

Such influence frustrates elected officials representing districts to the north, such as Gaithersburg City Council member Neil Harris, who supports Hogan’s plan.

“Most of the elected officials in the county live inside the Beltway, where improvements in transportation would be very different from what they would be for the rest of us,” Harris said. “If the down-county would benefit more from transit, and up-county would benefit more from roads, you end up with a political argument with everybody trying to get as many pennies as they can.”

Finally, there’s an ideological gap over whether to let private companies finance and then profit from toll lanes. In Virginia, Democrats supported that partly because Republicans previously controlled the state legislature. It was the only way to procure funds without raising taxes.

Hogan and some moderate Democrats favor that approach, but liberal Democrats are skeptical. They’re pushing the state to provide evidence that private financing would provide the most cost-efficient traffic relief.

Both sides in Maryland may feel motivated to cut a deal. Hogan sees the toll lanes as a signature legacy project. Elrich may not want to appear inflexible as he prepares to seek reelection next year.

A compromise could include adding the toll lanes but increasing promised investments in transit. One side would have to yield on whether to add two lanes or four.

Isiah “Ike” Leggett, Elrich’s predecessor as county executive, told the news website Maryland Matters that Hogan and Elrich should be locked in a room until they agree. It may be the only way.