The Moore administration’s east-west Red Line transit project is expected to take between six and 12 years to complete and will likely cost between $1.9 billion and $7.2 billion, depending on the mode of transportation, extent of tunneling and route on which officials decide, according to estimates the Maryland Transit Administration released Wednesday.

Baltimore residents and organizations have awaited an east-west transit system for decades.

Plans for the Red Line began in 2002 and progressed slowly until 2015, when Republican former Gov. Larry Hogan returned more than $900 million federal funding and halted the project.

Democratic Gov. Wes Moore campaigned with a promise to revive the Red Line, and he did so this summer.

After waiting more than 20 years, city and county residents have said to transit officials that they want the project completed as soon as possible.

The state, though, is entering a period of financial uncertainty, staring down projections of a structural operating deficit and a capital transportation plan that’s expected to have a funding gap of more than $2 billion in six years.

Federal transit officials have pledged support for the project, and U.S. Sens. Ben Cardin and Chris Van Hollen have pushed for greater funding consideration for dormant or previously inactive projects like the Red Line. But continued support from Washington will depend on who wins the 2024 presidential election and which party controls Congress in the years ahead.

The Maryland Transit Administration is hosting a series of open housing meetings beginning Thursday to solicit feedback from city and county residents on six Red Line route and mode options.

“Any of these would be hugely beneficial for the region and we really just want to get feedback from the public over the next month,” Maryland Transit Administrator Holly Arnold said in an interview.

The Red Line will run from the Centers for Medicare & Medicaid Services headquarters in Woodlawn through West Baltimore and into downtown Baltimore before ending in the Bayview area.

It will either be a light-rail system or a bus rapid transit network, which the Federal Transit Administration defines as more than simply an expansion of a city bus network; it includes dedicated lanes, busways, traffic signal priority, off-board fare collection, elevated platforms and “enhanced” stops and stations.

Compared to a Red Line bus rapid transit network, a light-rail system is projected to have nearly double the ridership, including among households without a car, but it could cost billions of dollars more, take years longer to complete and cost the state about $20 million more annually in operation and maintenance expenses.

The light rail, though, would be a more cost effective option, saving the state money in annual capital costs per trip compared to bus rapid transit.

An end-to-end trip would take about the same amount of time on light rail as it would on a bus, but city and county residents have a preference.

“There is definitely a preference in the communities for light rail over (bus rapid transit),” Arnold said. “And then there’s a lot of confusion about what (bus rapid transit) actually is.”

Building a light-rail system without tunneling would cost between $3.2 billion and $4.6 billion and take seven to nine years to complete, while a bus rapid transit network along the same proposed routes would cost between $1.9 billion and $2.7 billion and take six to eight years to complete.

Community organizers and business leaders in Baltimore have said that a proposed bus network wouldn’t be well received, while Moore has said there isn’t much data to support that argument and stressed that the state won’t decide on a transportation mode without community input.

Arnold has said that people have had misconceptions about the idea, and she has cited a need to educate the public about the difference between bus rapid transit and the city’s existing dedicated bus lanes. She and her team have shared pictures and videos of bus rapid transit networks in other cities to clear up the confusion.

One of the Maryland Transit Administration’s proposed routes includes building two tunnels — one under Cooks Lane in the West Hills area and another under downtown.

While tunneling would shorten the Red Line’s end-to-end travel time by 10 to 15 minutes and is projected to boost ridership, it would increase the project’s price tag and timeline, for both proposed modes of transportation.

“There is more risk associated with the tunnel,” Arnold said. “That’s not to say you can’t do a tunnel. Lots of cities do tunnels. We have a tunnel here in Baltimore. But it’s just one of the considerations.”

With tunneling, an end-to-end trip would take between 44 and 47 minutes on a Red Line light rail and between 45 and 48 minutes to cover the same distance by bus rapid transit, according to the Maryland Transit Administration.

Proposed routes without tunneling take between 55 and 59 minutes by light rail and between 56 and 60 minutes by bus.

Tunneling would also decrease the project’s cost effectiveness, resulting in a higher annual cost to the state per trip.

The primary difference between the three proposed Red Line routes — each of which could feature a light rail or bus rapid transit — is the path they follow through downtown and into the eastern part of the city.

The proposed route that includes tunnels under Cooks Lane and downtown Baltimore received community support and federal approval in 2012. It would make for the quickest trip, but it would also be the most expensive and take the longest amount of time to construct.

Unlike the tunneling route, the two proposed above-ground routes run along Security Boulevard so that the Red Line would be closer to planned developments at Security Square Mall in Woodlawn.

The two surface routes diverge when they reach downtown. One follows Baltimore Street and Lombard Street to Eastern Avenue and Fleet Street before reaching Bayview.

The other goes along Pratt Street, running close to Harborplace, and briefly follows Eastern Avenue and Fleet Street before turning south to align with Boston Street before hitting Bayview.

Arnold said she’s been asked whether the proposed routes can be mixed and matched.

“The short answer is yes,” she said. “That’s one of the things that we’re gonna be looking at and pieces of feedback that we want to hear over the next month.”