Main Street between Saco and Biddeford will be closed this weekend while work is done on railroad tracks and a bridge.

The construction work to replace the Main Street bridge that carries both vehicle and train traffic will also affect Amtrak Downeaster service.

The Maine Department of Transportation and Pan Am Railways will be working in the area on Saturday and Sunday. Saco Police say Main Street between Water and Gooch streets will be closed both days to all pedestrian and vehicle traffic.

Traffic will be diverted from Main Street to Elm Street (Route 1). Detour signs will be posted and local businesses will still be accessible, police said.

Amtrak has announced several service changes starting Friday because of the project. On Friday, there will be normal train service except for trains 687 and 689, which will terminate at the Wells station. Passengers traveling to Portland, Freeport and Brunswick will be transported by bus from Wells. There will be no service to Saco for those two trains.

On Saturday and Sunday, southbound passengers from Brunswick, Freeport and Portland will be taken by bus to Wells to meet the train. Northbound passengers traveling to Brunswick, Freeport and Portland will transfer from the train to continue north by bus, according to Amtrak.

No Downeaster service will be provided to or from Saco on Saturday or Sunday.

Amtrak says Monday service could also be affected if the project is not completed on time on Sunday. If work continues Monday,  passengers from trains 680 and 682 traveling from Brunswick, Freeport and Portland will be taken to Wells by bus and there will be no service to Saco.