A big-rig driver who crashed on northbound Highway 101 in San Rafael Monday, causing a massive traffic jam during the morning commute, had a blood-alcohol level more than five times the legal limit for commercial drivers, the CHP said.

Richard Earl Long, 56, was arrested on suspicion of felony DUI at Marin General Hospital, where he and a passenger were treated for minor injuries following the 8 a.m. crash.

The CHP said the American Canyon man was heading north on the highway when his flatbed truck drifted onto the shoulder near the central San Rafael exit and struck a concrete bridge rail.

The truck, which had a crane affixed to it, landed on its side with its load of steel I-beams still attached. The overturned truck blocked three left lanes of the highway, creating a massive backup during the heart of the morning commute. Southbound traffic also slowed to a crawl.

The highway was cleared and all lanes reopened around 11:30 a.m., according to police.

The legal blood-alcohol limit for commercial drivers is .04 percent, half the level for regular motorists.

Long was booked at the Marin County jail following his release from the hospital.

You can reach Staff Writer Derek Moore at 707-521-5336 or derek.moore@pressdemocrat.com. On Twitter @deadlinederek.