Plans for a 24-mile bike path between Salem and Concord may be derailed by railroad preservationists.

Area rail revitalization advocates want to preserve the abandoned rail for potential use as part of a new line.

Peter Griffin, president of New Hampshire Rail Revitalization Association, said state officials should hold off on a decision until completion of a planned two-year review of the region's transportation needs, to be conducted jointly with Massachusetts.

The Weare-based railroad group, which claims more than 100 members from New Hampshire, Massachusetts, Maine, and Vermont, favors using the Lawrence-to-Manchester corridor as part of a new system that would also provide a direct connection to Boston. But the corridor may be wide enough to accommodate the proposed bike path as well, Griffin said.

"I think a bike path is a very commendable way to add a transportation alternative to the mix. My concern is no commitment should be made for the corridor until this transportation study is completed and towns along the corridor have begun a process where their long-term transportation needs are identified," said Griffin, a Windham resident.

"There doesn't seem to be a willingness to share the corridor, which there needs to be," he added.

The $8.4 million project did get a positive recommendation from a citizens' advisory committee this week.

A panel of residents from the 11 towns and cities along the planned corridor were slated to present its findings and opinion to state Transportation Commissioner Carol Murray Thursday.

The plan by the Department of Transportation calls for a network of converted rail, new trail, and existing roads.

The project's estimated $8.4 million price-tag - not including engineering and land acquisition costs - would be paid with state and federal funds. The route would consist of a 12-foot-wide paved trail along 24 miles of converted railroad right-of-way from Salem to Manchester, then run along public roads before linking up with a new trail leading to Concord. Following an abandoned rail line that ran from Lawrence, Mass., to Manchester, the route would accommodate a wide range of users because it is mostly flat, transportation officials say.

State transportation officials haven't set a timetable for deciding whether to give the project a green light.

The project manager, Ram Maddali, did say recently that it will be crucial for the communities along the proposed corridor to demonstrate support and a willingness to work together.

"Once you know how much public support you've got, then all the future steps could be laid out," Maddali said.

Aimed at providing a new recreational resource for Southern New Hampshire that could double as a travel alternative to Interstate 93 for cyclists and pedestrians, the project has generated a good deal of buzz among local residents and businesses.