YARMOUTH — Yarmouth business owners said Tuesday that they would prefer that neither road be completely closed during construction of a replacement overpass carrying Route 1 over Main Street.

But a phased approach leaving a lane open on both roads could increase the construction timetable, said Tim Bryant, of VHB, the engineering consultant assisting with project design. Bryant said his group would re-assess how phased construction would work.

“In our experience it’s always two to three times longer,” Bryant said.

Business owners said the ideal would be to close only one lane at a time on the bridge, with temporary signals controlling the flow of traffic.

Tuesday’s meeting was the first time the Yarmouth Bridge Advisory Committee and engineers heard from business owners about how the construction could affect their livelihoods.

John Kyle, owner of Pat’s Pizza, said that he and other business owners on Route 1 would prefer the road not be completely closed for any period.

“I know I speak for a lot of them, any way we can keep the traffic flowing would be preferable.” Kyle said.

Currently, the overpass has four lanes; one through-lane of travel in each direction, and an off-and-on-ramp lane in each direction.

The bridge could be narrowed to two lanes in some versions of the bridge-replacement plan under consideration, with wider shoulders on either side.

Initial plans called for construction to take at least 45 days with Main Street closed for approximately one week, but phasing the construction could stretch that timetable.

Planners talked through a handful of options for the new traffic pattern on the bridge. In one scenario, a traffic signal would be installed at the bridge only in the south-bound travel lane and on the south-bound on-ramp from School Street, allowing pedestrians traveling on Route 1 to move across School Street under a dedicated signal.

Bryant said the initial engineering phase will likely be complete by fall, with a roll-out of options to the Town Council and the public in November. Construction is tentatively planned for 2017 at the earliest.

State transportation planners and a town committee are hashing out what the new bridge structure should look like and how traffic will flow over it and onto local streets. It was built in 1954 and is slated to be replaced by 2017.

Early plans had suggested doing away with the bridge and having Main Street and Route 1 intersect, but planners have moved away from that concept, instead examining how to add safety features and make a bridge more usable for pedestrians and cyclists.