The eastbound Highway 401 in Mississauga has re-opened after a tractor trailer collided with an SUV on Sunday morning. 

Around 7:25 a.m., the driver of a Toyota RAV-4 travelling eastbound lost control of his vehicle and hit a cement barrier. Unable to swerve out of the way, a tractor trailer collided with the SUV, said Sgt. Dave Woodford of the Ontario Provincial Police. 

The crash sent the Toyota's three occupants to hospital. The male driver suffered minor injuries, while the two female passengers were airlifted to St. Michael's Hospital. One woman is in critical condition, while the other sustained "life-threatening injuries," Woodford said.

Woodford said the eastbound lanes of the 401 re-opened at around 10:30 a.m., but nearly an hour later, a car crashed into a provincial road-salting truck at the same spot, blocking the centre lane. The lane has since re-opened.  

Sunday's collisions come after the first big storm of season heaped snow on southern Ontario, causing headaches for motorists across the region. 

This weekend, Woodford said, there have been more than 1,000 collisions on OPP-monitored roads in the Greater Toronto Area. Most of those incidents involved a single vehicle sliding off the road or into a guardrail.

"People are just driving too fast," Woodford said. "It's just ridiculous."