Federal highway officials are giving communities from the District to San Francisco the green light to paint their roads red.

Beyond providing new ground for bad puns — Washington “Cuts the Red Tape for Red Lanes,” the National Association of City Transportation Officials crowed — the move could mean better bus rides in traffic-snarled corridors.

The red transit lanes have been installed in New York, Chicago, San Diego County and elsewhere, but in those and other cases, local officials had to seek special “experimental” approval from the Federal Highway Administration, then provide reports on how they performed.

But last month, the agency, citing years of analysis and appeals from local jurisdictions, said it will give states the go-ahead to paint their transit lanes red if they write seeking permission and follow basic conditions, such as keeping a list of their locations. A state can seek the approval for all of its jurisdictions at once.

“Red paint has been shown to be effective. . . . It’s helpful to have their endorsement for the concept,” said Jeff Marootian, director of the District Department of Transportation, which has red-hued transit lanes on H and I streets NW downtown and is planning more on the heavily traveled 16th Street NW and in all of the city’s eight wards.

One purpose of the lanes is to try to make bus travel smoother and more attractive and to improve commutes. D.C. officials are planning to test enforcement cameras along the lanes and on buses themselves in 2020. They said decisions on ticketing will flow from that research, and fines are not imminent.

Marootian cited “tremendous benefits” thus far from the red bus lanes on H and I streets, which also include new signs, relocated loading zones and painted stencils in the road notifying drivers where they can drive through the red to make a right turn, among other adjustments.

With the changes, “we have been able to see improvements in how buses move,” Marootian said, though he added that data painting a more precise picture is still being worked on.

Federal officials left one asterisk in the process, noting that the promised smoother permissions will still technically be considered “interim approvals.” That’s because the Manual on Uniform Traffic Control Devices for Streets and Highways, the final word on paint and other standards, is still going through its years-long revision process.

If the final manual shifts course on red lanes, or if “significant safety concerns are directly or indirectly attributable” to the lanes in particular places, the paint would have to go, the officials said.

Still, the data on the benefits of red paint has been convincing so far, federal officials said.

“The results of multiple experiments showed that red-colored pavement reduced the unauthorized use of transit lanes by private vehicles, reduced illegal parking in transit lanes, and reduced the travel times of transit vehicles through the corridors,” the Federal Highway Administration said in a statement.

In San Francisco, for example, the red lanes along 3rd Street cut “the number of drivers violating transit lanes by 48 to 55 percent, depending on the time of day — even as the street saw more car traffic,” according to the city’s transit agency.

Of course, the red lanes are not a panacea or universally welcomed, despite being dubbed “red carpet lanes” by boosters. Federal highway officials noted, for example, that not all potential benefits were found in every place where the lanes were put in, though “the majority of sites observed showed at least one.”

As is common when city planners change the rules on when and where cars can travel, stop or park, some drivers and business owners have balked. In its notice to local officials, Federal Highway Administration officials noted “concerns from business owners that the red-colored pavement might confuse drivers into believing they could not access the businesses on the right side of the roadway” and suggested public information campaigns or added signs could help.

There had also been concern that drivers seeking to stay clear of the red zones would cut over dangerously at intersections. But the federal notice said results from local experiments showed that “the red-colored pavement did not induce drivers of private vehicles to make turns from the incorrect lane.”

In some cities, such as the District, bikes are allowed in the bus lanes, creating some anxiety about potential dangers or conflicts.

“Although some transit agencies are wary of sharing heavily used transit lanes with slower-moving cyclists, most planners reported few if any problems with the arrangement,” according to research released last year by the UCLA Institute of Transportation Studies. The report cited the perspective of Patrick McMahon, a senior planner at the Maryland Transit Administration, who argued that sharing transit lanes with bikes provides a key benefit for people on buses: “Bikes keep out cars.”