EL PASO -- Leaving the car in the garage and taking a passenger train from El Paso to Santa Fe sounds inviting.

It most definitely would be expensive, City Council members were told Wednesday in a briefing on the concept.

Connecting El Paso and Las Cruces to the Rail Runner Commuter System that now runs between the Albuquerque area and Santa Fe could cost up to $735 million. That was the price quoted to the El Paso and Las Cruces city councils by officials with the New Mexico Department of Transportation.

The councils, which met in El Paso, agreed to keep working on securing money for the project that would probably first connect El Paso and Las Cruces using Burlington Northern Santa Fe tracks. Then it would be expanded north to connect with the existing Rail Runner system in Belen, N.M., south of Albuquerque.

"Commuter rail is something we definitely need to look at. We have a lot of people that make the commute every day," El Paso Mayor John Cook said. "And if we want to really think green when we think about transportation, we need to start talking about this now."

Roy Gilyard, the executive director of the El Paso Metropolitan Planning Organization, said about 18,000 people commute between El Paso and Las Cruces every day. He said 30 percent of them come from Juárez.

New Mexico transportation officials say it is not easy to come up with a concrete figure on the cost of connecting the border region to the Rail Runner system because the project's scope is unclear.

Figures from New Mexico ranged between $175 million if existing rails were used to well over $700 million if crews were required to build or upgrade tracks.

New Mexico has spent more than $300 million since 2006 to buy tracks from the Burlington Northern Santa Fe railroad to establish the Rail Runner Express, which runs between Belen and Santa Fe.

Members of both city councils said the most feasible option for the region would be to lease the right of way covering existing tracks instead of buying it outright.

Rich Wessler, the director of passenger train operations for Burlington Northern Santa Fe in Fort Worth, said significant work would be needed on 222 miles of track linking El Paso and Albuquerque.

Chief among the concerns is the condition of the rails, which allows for a maximum speed of 55 mph.

"That's conducive for freight, but it wouldn't work for passenger service," Wessler said.

He said signs and crossings along the route would also need to be upgraded.

"We are prepared to have a dialogue if we address the safety improvements and liability issues that I have brought up," Wessler said. "Once that happens, there's a very good chance that a partnership could be created."

The councils didn't take action on Tuesday, but New Mexico state Rep. Jeff Steinborn of Las Cruces urged each body to adopt a resolution supporting the expansion of the commuter rail system into the region.

Steinborn said the New Mexico Legislature should have a feasibility study on expansion of the system by next year, and he said that some money is available from the federal government to get the project started.

"The stimulus package has $6 billion to $8 billion for commuter rail development," he said. "Transportation is going to be a challenge as our regions grow. We need to be ahead of it."

Eastridge/Mid-Valley city Rep. Steve Ortega asked that any study that is commissioned include the expansion of commuter rail services into Mexico.

"There should be some efforts to include the state of Chihuahua into our conversations," he said. "When we talk about the region, Juárez is definitely the big dog" in population.