Long-awaited toll lanes that will run a 16-mile stretch of the 405 Freeway between Costa Mesa and the Los Angeles County line are expected to open on Dec. 1, according to the Orange County Transportation Authority.

The lanes have been installed during a yearslong process that saw the agency build 18 new bridges as well as one additional general-use lane and two new toll lanes for both southbound and northbound traffic.

While the tolls will be adjusted quarterly, the introductory rates are expected to cost drivers about $3 per trip during non-peak hours for the entire stretch and a maximum of about $10 during peak hours on Fridays (3 p.m. to 5 p.m.), according to the agency.

The northernmost entry point for the lanes starts near the intersection of the 405 and 605 freeways and ends where the 405 and the 73 Freeway connect. The $2.1 billion project was paid for predominantly through sales but also with the help of state and federal funds.

OCTA’s project site said that the tolls collected will help pay back the $629 million loan from the federal government that was taken out to complete the project.

There will be some exceptions to paying the tolls with vehicles with two or more passengers being exempt from paying a toll for the first 3.5 years during non-peak hours, which are outside the hours of 6 a.m. to 10 a.m or 2 p.m. to 7 p.m. Monday through Friday. Weekend non-peak hours are outside the hours of 1 p.m. to 7 p.m.

However, vehicles with two people will have to pay a toll during peak hours.

Vehicles with three or more people will always be free as will vehicles with designated veterans’ license plates, disabled license plates and motorcycles. Clean air vehicles will be eligible for a 15% discount, according to OCTA.

Vehicles will be required to have a FasTrack transponder, which can be purchased from California toll agencies for about $15, but drivers who already have a transponder for other toll roads in the region won’t have to buy a new one to use the new 405 toll lanes.

However, to be able to qualify for the free or discounted tolls drivers will have to have a switchable transponder.

To learn more about the toll lanes and how they work you can visit the 405 Express Lanes website here.

Editor’s note: This story was updated to correct the Orange County Transportation Authority’s name.