Big additions to Metro are among “aspirations” presented by transportation planners. (Sarah L. Voisin/The Washington Post)

There are aspirations. And there are political realities. On Friday, the Washington region’s top transportation planners offered their ideas for how to handle both.

Riffing off a federal requirement that they tally road and transit projects that have a “reasonable” chance of being funded, regional leaders also described a series of “aspirational initiatives” that would be harder to pull off.

Their idea was to present a practical, long-range plan — stretching out to 2045 — but also to jump-start policy and funding conversations on ideas some consider impractical but that would improve people’s quality of life decades from now.

So in addition to listing 600 transportation projects deemed doable under current funding constraints, including toll lanes on Interstate 66, bike lanes in the District, and the Purple Line light-rail project in Maryland, the regional officials also presented a seven-part philosophical treatise and wish list that takes some bigger swings at intractable problems.

They want to:

** Move more people on Metro, by expanding the most crowded stations, adding a second one in Rossyln, and building an “inner loop” that would cross the Potomac in a new tunnel and connect Virginia to Georgetown. (Those would come on top of existing plans to increase the number of eight-car trains throughout the system.)

** Greatly expand speedy “bus rapid transit” lines, including with dedicated lanes, something already being pursued in Montgomery and Fairfax counties and elsewhere; and pursue more streetcar and light-rail routes.

** Put more jobs and housing together, a long-running priority, by greenlighting development at Metro stations “that aren’t as busy as others and have available space nearby for new construction” and by building more housing and offices in other central areas.

** Spur telecommuting and cut solo car trips by reversing current incentives. They would encourage companies and local governments to stop subsidizing parking in places where jobs and housing are already concentrated, and push for “parking cash-outs,” in which workers could get that money instead for transit or to commute in other ways.

** Expand the region’s network of highway toll and carpool lanes, beyond what Virginia has done along the Beltway and what Maryland is planning there and on Interstate 270, and create a new network of buses that could speed along them.

** Make walking and biking to transit stations and elsewhere “comfortable and convenient,” by fixing or building sidewalks and trails and making sure they have good lights and safe crossings across major roads.

** Build a “bicycle beltway” by adding more than 20 miles to a network of trails dubbed the National Capital Trail, which would connect dozens of rail stations and other busy areas.

The broad goals are meant to challenge the region to think creatively, and to avoid falling into believing that “one particular thing will solve the issue of transportation,” said Renée Hamilton, a deputy district administrator for the Virginia Department of Transportation.

“We need to look at the projects that truly move the needle,” said Hamilton, who serves on the region’s Transportation Planning Board, which produced the long-range document formally presented Friday, called Visualize 2045.

The planning board includes elected leaders from 23 cities and counties, as well as representatives from Maryland, Virginia and the District, the Washington Metropolitan Area Transit Authority and other bodies.

The two strains of the Visualize 2045 plan are meant to reinforce each other, backers argue. It accounts for the bulk of projects already on local government books — and it could help shape future ones. That’s important in a growing, congested and often balkanized region that needs regional approaches to transportation challenges that bleed across jurisdictional lines, they said.

“We don’t have the legal authority to construct anything, to operate anything, nothing. We are essentially a planning body,” said Kanti Srikanth, staff director of the Transportation Planning Board, which is housed and staffed by the Metropolitan Washington Council of Governments.

“Decisions are happening locally. But it’s a region,” Srikanth said. “What the transportation planning board does is … sit around the table and say okay, what are some values we as a region should have around transportation?”

Officials are seeking comments on the draft Visualize 2045 plan and are expected to vote on a final version next month.