A spill that left 13 tons of hot asphalt spread across most of southbound Highway 101 in Sonoma County fouled traffic for more than three hours on Thursday morning, the CHP said.

The spill, reported shortly after 9 a.m., covered 2 1/2 lanes and extended along some 50 yards of the highway south of Todd Road in south Santa Rosa, the CHP said.

It had a far-reaching impact on late-morning traffic. Southbound motorists were brought to a crawl, with speeds as low as 2 mph, and traffic was backed up to Hearn Avenue, the CHP said.

Southbound traffic was routed partially onto the center divider while Caltrans crews were dispatched to clean up the sticky mess, apparently left behind by a construction vehicle, according to the CHP.

The entire road was reopened at 12:11 p.m., authorities said.