After years of back and forth on plans for a new rail line downtown, Dallas Area Rapid Transit is shopping three possible routes for a billion-dollar subway to City Council members.

DART officials will update the council's transportation committee on the routes Monday. The meeting could jump-start a project that has at times been a sticking point between DART and city leaders who question whether the priority should be beefing up transportation options in the urban core or expanding them in the suburbs.

The DART board split the baby in October by voting to fund both the downtown subway and the estimated $1.1 billion Cotton Belt Corridor commuter line that will connect Plano to DFW International Airport.

D2 subway supporters listen during public comment before the board of the Dallas Area Rapid Transit before they voted on a rail corridor plan on Tuesday, October 25, 2016 at DART headquarters in Dallas. The board voted to finance both the Cotton Belt and D2 subway. (Ashley Landis / Staff Photographer)

DART hopes federal funds will pay for about half of the evolving price tag for the subway, about $650 million. The rest would come from sales taxes.

All four DART train lines — Orange, Green, Blue and Red — now run on the same track through downtown. DART wants to reroute the Orange and Green lines on the subway to increase capacity.

Having only one line limits how often trains can run across the entire network. And whenever there’s a problem downtown, like a car wreck blocking the track, a shooting, electrical outage or nearby fire, delays can affect passengers all over the system.

The Dallas council must sign off on the path of any light-rail route.

“It is an improvement just to get trains through downtown without having the congestion we have,” said council member Lee Kleinman, chairman of the transportation committee.

DART has long hoped to build a second downtown route. The council supports the project, but it has been slowed by the last economic downturn and because earlier routes have been rejected.

Some of the earlier routes would have run through historical sites such as Dealey Plaza, would have caused enormous construction headaches in the core of downtown, or were discarded because soil testing showed that building a subway in some areas would be prohibitively expensive.

So last year, the Dallas City Council asked DART to bury the line.

“The main thing to try to narrow down is alignments that provide the least amount of disruption for the property owners in the core of downtown,” said Kleinman.

DART went back to the drawing board and now has three potential routes. The agency hopes the project can be on track to be completed before 2024.

Proposed routes for downtown Dallas subway

Dallas Area Rapid Transit has narrowed proposals for a downtown subway to three routes. They don't offer much expanded coverage, but they do allow for an important alternate route for trains when parts of the system break down.

The existing line will split near the Victory Avenue station and a new station would be adjacent to the Perot Museum of Nature and Science. From there, the route would stay above ground, running under Woodall Rodgers Freeway before going underground near Field Street.

Then the route could go on one of three paths. One would be beneath Pacific Avenue along the existing line, with a new subway station connecting it to the existing Akard Station. From there, the line would travel up to Swiss Avenue, passing the existing East End Transfer station.

The Pacific Avenue route would allow for easy transfers because of its proximity to the Akard Station, and construction would not be extremely disruptive. But of the three proposed routes, this $938 million line would offer the least new coverage for riders.

“It’s that balance we are trying to figure out between making it easy for the existing ridership that we have to transfer and move, and also we want to open up the system to more riders to give more exposure to folks,” said Steve Salin, DART’s vice president of rail planning. “If you are on the same path, you aren’t going to do that as well.”

The second option would put the line one block farther south, running under Elm Street at an estimated cost of $1.29 billion. Riders transferring between lines would have to walk a few blocks from a new subway stop to Akard Station or the West End station. But this route would allow for a slightly increased coverage area and make all the stations less crowded.

“This station at Pacific could be really, really busy with all four lines transferring at one point. This kind of spreads that out a little bit,” said Chad Edwards, DART’s assistant vice president of capital planning.

The third option, at an estimated cost of $1.26 billion, would put the line farther south, running under Commerce Street. The line would pick up more coverage, but it would make it more difficult for riders to transfer between lines.

Competing interests

One concern is that the proposed subway routes wouldn’t expand coverage much.

The Dallas streetcar is seen through a maze of construction at the Bishop Arts stop, photographed on Thursday, April 13, 2017. (Louis DeLuca/The Dallas Morning News) (Louis DeLuca / Staff Photographer)

But extensions to the Dallas Streetcar — owned by the city but operated by DART — will eventually connect Uptown all the way to the Bishop Arts District, with a possible line running through south downtown and near City Hall.

Kleinman said that's a key issue for the council.

“We definitely want to ... enable some vibrancy and activity in the southern part of downtown, in that government sector and really that part of downtown that goes from the convention center to the government corridor to the [Dallas] Farmers Market, so that is a place where we want to enable more transit-type activity,” he said. “If we can do that with the streetcar, then we serve the purpose.”

East of downtown, the new subway would rise up to street level on Swiss Avenue as it approaches Deep Ellum. Property would have to be acquired and construction could be disruptive.

“DART wants the Swiss Avenue route to happen and we’ve pushed back really hard to say, ‘Are you sure this is the best option for the whole neighborhood and the whole city?’ No matter where it goes, it’s going to affect something,” said Jessica Burnham, executive director of the Deep Ellum Foundation.

Burnham said she’s not as concerned about a proposal to move the Deep Ellum station west of I-345 or closer to the freeway on the east side, since the nearby Baylor Station already serves the core of Deep Ellum. But she said she hopes DART would improve pedestrian access at the Baylor Station, something the agency says it is willing to do.

Burnham said it is important that DART also improve the whole system. “We still need buses to get to the station and we need the streetcar,” Burnham said. “There’s a lot of opportunity for growth.”

Interstate 345 divides Deep Ellum (right) and downtown Dallas (left) as the Chase Tower looms in the background on June 17, 2016 in Dallas, Texas. (Ting Shen/The Dallas Morning News) (Ting Shen / Staff Photographer)

She said she hopes DART will continue to be transparent with the affected neighborhoods.

Another complication is ongoing pressure on the Texas Department of Transportation to eliminate or bury I-345 — that short segment of raised freeway that cuts off Deep Ellum from downtown. There's been talk of moving the freeway to street level, simplifying the overhead structure by removing entrance and exit ramps, or putting the highway below ground level to reconnect parts of the city.

TxDOT says the subway plans wouldn't affect I-345's future.

After Monday’s council presentation, DART staff is expected to present its recommended alignment to the DART board in late May. The full City Council is expected to vote by the end of the summer so DART can submit plans to the Federal Transit Authority by a Sept. 1 deadline.