A transit advocacy group in Montgomery County wants a second entrance installed sooner than scheduled at the Bethesda Metro station because it worries that there will be hiccups in plans to install new escalators at the current one, causing severe crowding and long lines.

The new Elm Street entrance, accessed via elevators, would take riders to the Purple Line, a proposed light-rail connection between Bethesda and New Carrollton, and Metro’s Red Line.

Metro plans to tear out the old, balky escalators at the station’s north entrance and put in three new ones. But that work won’t start until 2014.

The Action Committee for Transit said long lines could result while those new escalators are being installed if one of the units that remains in service during the work breaks down.

“Every now and then, one of those two escalators is going to break down, and then you’re down to one that has to be stopped and be used as a stairway,” said Ben Ross, vice president of ACT. There will “be a big crowd, and people have to walk up it slowly because it is so deep.”

That’s a situation already familiar to commuters who have been plagued by escalator breakdowns at the station, which has only one entrance.

On Tuesday, ACT passed out more than 5,000 fliers at the Bethesda station asking riders to write to the Montgomery County Council to voice their concerns.

The group’s proposal: Build the new south entrance with elevators sooner rather than later.

Those plans have been on the drawing board as part of the proposal to build the 16-mile Purple Line, a state project that is estimated to cost $1.93 billion and is awaiting federal approval to begin preliminary engineering. That decision is expected soon, but it’s unclear where construction money would come from. The project would rely on federal and state contributions.

Montgomery is funding the proposed $60 million elevator project. But transit advocates say Montgomery is delaying the elevator project. The county disagrees.

The elevator design is being done “in tandem with the Purple Line,” said Esther Bowring, a spokeswoman for the county’s transportation department.

“It would be like building an elevator before you have a building,” she said.

If the elevators were built before work started on the Purple Line, she said, they would have to be shut down while the line is built.

Gary Erenrich, special assistant to the director for Metro affairs in Montgomery, said the two projects have to “meet and work together.”

Consultants for the Maryland Transit Administration are working on developing the Purple Line and the details of the elevators at Bethesda, he said.

“We’ve only done conceptual design of the whole Purple Line,” he said. “We haven’t done any engineering. We believe the [elevator] project has to be under construction at the same time as the Purple Line because of the proximity of the work and the inter-relationships.”

Dan Stessel, Metro’s chief spokesman, said in an e-mail that “a second entrance at Bethesda station will be good for our customers by improving access and easing congestion at the existing station entrance.”

The transit authority has a plan to spend more than $150 million to rehabilitate and install new escalators and elevators throughout its system. Metro also recently decided to contract out work to maintain escalators on the Orange Line from Rosslyn to Vienna.