A tractor-trailer overturned Thursday amid high winds at the 60 Freeway/Interstate 15 interchange in Eastvale, prompting a full closure of a connector bridge.
The crash happened around noon on the eastbound Pomona (60) Freeway transition to northbound I-15, according to the California Highway Patrol.
Intense Santa Ana winds were blowing through the area at the time, but it was unclear whether that was what caused the driver to lose control.
The big rig jackknifed on its passenger side in the No. 2 lane, and the trucker was able to self-extricate, the CHP said. The man was uninjured.
No other vehicles were involved.
Riverside County Fire Department crews reached the location a short time later and discovered diesel leaking from the rig.
The entire connector was shut down at 12:25 p.m., and a SigAlert was issued immediately afterward due to the ensuing traffic jam.
Motorists were diverted into Jurupa Valley, where they could turn around and access I-15 via the westbound 60.
As of 1 p.m., tow crews were working to upright the rig.
The diesel spill was quickly mopped up, amounting to less than five gallons, according to reports from the scene.
The transition was expected to be reopened by 2 p.m.