Two separate crashes snarled northbound traffic on the Maine Turnpike Friday morning.

All three northbound lanes were closed in Scarborough after a 10:30 a.m. crash at mile 42 between the Saco and Scarborough exits. The travel lanes were all reopened by about 11:20 a.m., but traffic is backed up about 10 miles, said Erin Courtney, a Maine Turnpike Authority spokeswoman.

Courtney said the two-vehicle crash involved a truck and a passenger car. No injuries were reported, she said.

The traffic back-up could snarl weekend tourist traffic if the delays continue into the mid-afternoon, Courtney said.

“The closer we get to two in the afternoon, that’s when all the people start coming in,” She said. “There is a chance that it could dissipate before we hit that afternoon tourist traffic.”

The first accident happened around 7 a.m. further south in York when a dump truck traveling north hit an overpass at Clay Hill Road.

Both the center and driving lanes were closed to traffic after that crash, although all northbound lanes were reopened there by about 10 a.m., according to turnpike officials. Heavy delays continued for a couple hours because of the backup.

Courtney said the reason the dump bed struck the overpass is still under investigation. The truck’s driver was the only person involved and there were no injuries, she said.

An initial assessment of the overpass structure showed no signs of structural damage, but Turnpike engineers will continue to examine the structure to make sure it’s sound, she said.

This story will be updated.