Demolition crews tore down a half-century-old toll administration building on State Route 520 today, removing the last relic of cash toll collections on the highway and launching three years of major construction on the Eastside.

By crunching down and recycling the one-story building near Evergreen Point Road, crews are making way for the $306 million SR 520 Eastside Transit and HOV Project, which rebuilds the highway from Lake Washington to Bellevue. The Washington State Department of Transportation (WSDOT) is widening the corridor to six lanes from Medina to Bellevue and building better interchanges, enhancing the environment and adding new lanes and direct-access ramps for buses and carpools.

Tree clearing is scheduled to start as soon as next week along the SR 520 corridor. The next major construction milestone comes in June with full weekend closures planned for June 3-6 and June 17-20 from Montlake Boulevard to Interstate 405. Crews will need to close the corridor to safely dig deep trenches beneath all lanes of the highway for new fish-passable culverts.

“We’re going to need drivers’ help to avoid regionwide gridlock during these complete weekend closures in June – and periodically during the next three years,” said Brian Dobbins, WSDOT’s SR 520 Eastside project construction engineer. The closures are planned from 11 p.m. Friday, June 3, to 5 a.m. Monday, June 6, and during the same hours June 17-20. Additional complete weekend closures are likely each month during construction season.

The toll administration building demolished Monday was a remnant of the days when WSDOT collected cash-only tolls on SR 520, which ended in 1979. The building ­– and a walk-in vault once used by cashiers – later housed bridge equipment, parts and paperwork.

“The administrative building represented the very last of the old way of collecting tolls, opening up a new era of all-electronic tolling,” Toll Division Director Craig Stone said. “Technology enables us to collect tolls at highway speeds – eliminating costly cash handling and stop-and-go traffic.”

In place of the building, Eastside Corridor Constructors, the design-builder, will widen the highway with bus and carpool lanes, shoulders, a park-and-ride lot and lid at Evergreen Point Road, and a median transit stop.