By Charlie Breitrose

Watertown companies may be joining in with the Watertown Transportation Management Association in providing shuttle service for major businesses and large apartment complexes along Arsenal Street.

The Watertown TMA has been looking for ways to improve transportation options for members, including creating a shuttle service. Efforts to create a pilot shuttle service have not been successful, but the latest effort may be on track to become a reality.

Bridger McGaw of Athenahealth who also serves as president of the Watertown TMA, gave an update to the Watertown Town Council’s Economic Development and Planning subcommittee.

The shuttles would be an expansion of the current Athenahealth shuttle system, McGaw said. The company, which owns the Arsenal on the Charles complex, currently runs shuttles to Harvard Square, South Boston, Back Bay, North Station and the North End.

Adding new riders from other members of the TMA, however, will be done cautiously, McGaw said.

"It is very complex," McGaw said. "It is never as simple as just adding a stop, or saying why not just add a bus."

The TMA is made up mostly of companies and projects required by their building permits to contribute to the TMA (and in most cases the shuttle); some who have joined voluntarily; plus the Town of Watertown.

Watertown officials have discussed the desire to allow all Watertown residents to ride the Watertown TMA’s shuttle. Doing so is not as simple as it may seem, however, said Steve Magoon, assistant town manager and director of Community Development and Planning.

He said the Town would have to contribute its share toward running the shuttle, or people would have to buy passes, or both. Also, Magoon said, it might change the calculations for other businesses or residential complexes.

Many questions remain. "If it is available to the public, what is the incentive for a business to join the TMA?" Magoon said. "If the public can get on, what is a reasonable amount to contribute? And, if they sell passes what is a reasonable amount to charge?"