Town leaders in Tisbury and Oak Bluffs had their first look at the drawings for a permanent Lagoon Pond drawbridge last week.

The drawings were on display during a meeting at the Martha’s Vineyard Commission office in Oak Bluffs. The federally-funded $28.5 million project is expected to take three years to build; construction bids are slated to be advertised in the fall.

Since 2010 Vineyard drivers have been using the $9 million temporary drawbridge, which took six years to complete and has not been without its bugs (in 2010 the bridge became stuck in the upright position twice in two weeks shortly after opening).

While the engineering for the new bridge is nearly complete, most of the design elements, such as railings, lamps and bridge facade are still being debated by the two-town drawbridge committee. One prominent feature of the bridge, its tender house, was presented in blueprint on Thursday. Leslie Haynes from Parsons Engineering said the building, which houses the bridge operator, would be modeled after the tender house at the Woods Hole drawbridge. The 15-by-15-foot house will be clad in cedar shingles and white PVC trim with a chimney-like flue for the emergency generator. Designers also put forward plans for a vegetated swale on the Vineyard Haven side of the bridge to treat stormwater runoff.

As for the rest of the design elements, the session featured hours of discussion on what types of lighting, railing and stonework best fit the Vineyard style. Tisbury selectman Tristan Israel suggested putting a town line of demarcation on the future bridge to help resolve scalloping disputes.

Massachusetts Department of Transportation project manager Steve McLaughlin said this week drivers may notice a team of engineers surveying the current drawbridge.