Montgomery County Executive Isiah Leggett (D) (Jeffrey MacMillan)

Montgomery County Executive Isiah Leggett (D), looking to accelerate development of long­discussed and costly mass transit projects, has asked state lawmakers for clearance to create an independent authority to oversee the work.

A bill introduced Friday on Leggett’s behalf by Montgomery legislators would enable the county to form an agency focused on financing, building and operating a planned network of bus-only lanes to relieve chronic traffic congestion. The transit authority, which requires approval by the County Council, would be funded by a new countywide mass transit tax. It would also be empowered to borrow money on its own through the sale of bonds.

Leggett floated the idea of an independent transit agency in his December inaugural speech, saying that “the strong possibility of continuing budget challenges on the state level” — meaning deficits coupled with new Gov. Larry Hogan’s apparent preference for road construction over mass transit — made it imperative that the county find a way to shoulder more of the costs.

The authority would assume operation of the Ride On bus system, which is currently under the control of the county’s transportation department, an agency that also oversees road construction and maintenance. Leggett, who would appoint members to the authority’s board of directors, said the county’s ambitious transit plans require an agency focused on that mission.

“He believes an agency with a single focus on transit is essential,” said assistant chief administrative officer Tom Street, who briefed council members on the bill at Monday afternoon’s meeting.

Montgomery residents pay a mass transit tax to underwrite Ride On, a levy that will bring in an estimated $69 million this fiscal year. Under the bill, the tax would be replaced by a new countywide transit tax to help fund the authority. The council would set the new transit tax rate but would not be limited by charter provisions that cap the amount of revenue the county can bring in each year.

By operating outside the charter limit, the county could begin to fund two long-planned bus-rapid-transit ventures. One would create a 98-mile network of bus-only lanes along some of the county’s most congested roads, including Rockville Pike, U.S. 29 and Veirs Mill Road, at an estimated cost of $1 billion to $2 billion.

The other bus project, the Corridor Cities Transitway, would link the Shady Grove Metro station to the Metropolitan Grove area of Gaithersburg at a cost of about $540 million in 2012 dollars. The new authority could also coordinate construction of the 16-mile Purple Line linking Bethesda and New Carrollton.

Montgomery council members said Monday that they supported the general framework of the bill but that Leggett had left them unprepared for its introduction on Friday. Leggett’s spokesman, Patrick Lacefield, said elements of the bill “have been discussed with pretty near all council members over the course of the month.”

Council members said they wanted to explore details of the bill until the first of next week before formally endorsing it.

They also promised that the public would have ample opportunity to weigh in before the council took final action on creating the authority.

The Montgomery legislative delegation will hold a public hearing on the bill at 6 p.m. Friday in the council chambers.