FALMOUTH — The Maine Turnpike Authority will institute a new, construction-related traffic pattern on Monday for travelers on the Falmouth Spur.

The new traffic pattern is needed to ensure motorist and worker safety during the two-year reconstruction of the Presumpscot River bridges.

Traffic will be restricted to single lanes in both directions.

Westbound motorists will be directed to cross over onto the eastbound bridge while crews reconstruct the westbound bridge.

This first phase of construction should wrap up late in 2012, and be followed by further construction that will require additional traffic pattern changes.

All schedules are weather-dependent and subject to change.