Starting Saturday morning, the toll lanes will open between the south side of Corona and the 60 Freeway in Eastvale.
The $472 million I-15 Express Lanes Project, which began in March 2018, is largely finished, though a few finishing touches will be applied in the months ahead, according to the Riverside County Transportation Commission.
"RCTC is excited to open these new lanes to provide another way to get to work, school or recreational destinations," RCTC Chair Tem Jan Harnik said. "We know that time is precious, and the express lanes offer convenience and reliable trip times for drivers."
The project entailed installing two toll lanes on both the north and southbound sides of I-15, covering a 15-mile stretch.
Officials say the toll system will work like the one on the 91 Freeway in Corona, with motorists required to have a FasTrak transponder attached to their cars.
City News Service contributed to this report.