A man is in hospital with critical injuries and a woman suffered a broken arm in a one-car crash in Canterbury overnight.

Police were called to the crash at the intersection of Station Rd and Loburn Whiterock Rd in Loburn shortly after 1.30am.

The car had crashed and rolled, injuring two people inside it, a police spokeswoman said.

A man was flown to Christchurch Hospital by helicopter in a critical condition and a woman suffered a broken arm.

Advertisement

Police were investigating the cause of the crash which was not yet known, the spokeswoman said.

It's been a horror week on our roads, with seven people - including two pedestrians hit by a train - dying in separate incidents in a deadly nine-hour period on Friday.

National manager for road policing Superintendent Steve Greally said Friday night's fatalities came off the back of a "disastrous" month on our roads.

"Seven people. That's seven families [affected]. That's seven lives that have ended over 24 hours, that were all here when we woke up yesterday morning...yet today they are not.

"It's just so sudden. It's so hard for those families to deal with."