A multi-vehicle crash prompted the California Highway Patrol to issue a SigAlert Tuesday afternoon.
Around 12:15 p.m., three cars and a motorcycle crashed on northbound Interstate 15 at Carroll Canyon Road.
The CHP had to close the HOV lanes, creating a traffic backup on the freeway.
Six people were taken to the hospital with minor injuries, according to the CHP.
View Carroll Canyon Rd & Interstate 15 in a larger map