The Commonwealth Transportation Board approved a plan Wednesday for I-66 inside the Beltway, one of the nation’s most congested highways. The plan calls for rush-hour tolling to begin in 2017, with all toll revenue reinvested into the I-66 corridor inside the Beltway.

Construction of the toll system is expected to begin in the summer.

UPDATE: Design Public Hearings: March 7: Arlington

March 8: Ashburn

March 9: Fairfax

The key highlights of the plan include:

If you carpool today (two or more people in a vehicle), you will continue to ride the lanes for free when dynamic tolling is scheduled to begin in 2017 during morning and evening rush-hours (5:30 a.m. to 9:30 a.m. eastbound and 3 p.m. to 7 p.m. westbound).

If you drive solo, then you can ride the lanes by paying a variable toll during rush hours based on the distance you travel. Average toll is expected to be $6 a trip.

a trip. In 2020, lanes will be free to vehicles with three or more people during rush-hours (carpoolers, vanpools and buses) and motorcycles per adopted regional policy. All others, including two or more people, will pay a variable toll.

The lanes will remain free to all traffic during off-peak periods . There will be no tolling in the reverse commute.

. There will be no tolling in the reverse commute. All of the revenues raised from the tolls will finance transportation improvements in the corridor. Estimated toll revenue in 2018 is $18 million.

Should traffic not flow better in five years, toll revenues will be used to widen I-66 eastbound from the Dulles Connector Road to Ballston.

A separate plan is under consideration for I-66 outside the Beltway to Gainesville.