An unidentified object recently appeared on Beach Road on both sides of the Big Bridge, an object as foreign to some Islanders as a shopping mall or an alien spacecraft.

Of course it is only a stoplight, a rather common item in other parts of the world, but something of a curiosity on the Vineyard. This particular light is only temporary, and has been set up to direct traffic while work takes place during the off-season on the Big Bridge and the Little Bridge down the road.

The bridges are formally named VFW Memorial Bridge (the small bridge on the Oak Bluffs end of the road) and American Legion Memorial Bridge (the big bridge that sits on the Oak Bluffs and Edgartown town line).

MassHighway is planning to replace both bridges in two phases over the next two winters. MIG Corporation of Acton is expected to replace half of each bridge by next Memorial Day and complete the work next fall and winter. The Big Bridge has been reduced to one lane, hence the stoplight.

The light has a longer wait time than most in order to allow vehicles to cross the entire span of the bridge before the light changes.

Perhaps as a precaution, state police have intermittently been stationed at both ends of the bridge over the past two weeks, just in case people forget the basic stop light rules of green means go and red means stop.

Edgartown police Sgt. Kenneth Johnson said motorists have adapted to the traffic light just fine.

“No problems at all. People have adjusted,” he said.