James Leigh is nursing numerous broken bones after being hit by a car while walking on a footpath in central Christchurch (STOCK PHOTO).

A Christchurch pedestrian has been critically injured after being hit by a car driven by man who has since been charged with driving drunk and speeding.

The driver was allegedly speeding when he crossed a raised cycleway on Cambridge Tce in the central city, mounted the footpath and crashed into James Leigh, breaking his pelvis, vertebrae, leg, forearm and thumb, about 11.40pm on Saturday.

Leigh's fiancee Olivia Timmings said her partner was lucky to have survived as she believed the driver, who police said was over the drink-drive limit, was travelling about 80 kilometres an hour in the 30kmh zone.

She said Leigh had left Fat Eddie's bar on nearby Hereford St alone and was walking to meet an Uber to go home. She said he remembers seeing a glowing set of headlights zooming towards him before he was hit.

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The driver climbed out of the car and reportedly started to walk away, but was grabbed and brought back by a bystander. A woman in the vehicle following the driver pulled over to help Leigh and witnesses called emergency services.

A police spokesman said a 27-year-old man had been arrested and charged with driving dangerously causing injury and excess breath alcohol.

Police called Timmings shortly after the crash and told her to meet them at Christchurch Hospital's emergency department.

JOHN KIRK-ANDERSON/STUFF Leigh was on Cambridge Tce, near this spot, when a speeding drunk-driver crossed a raised cycleway, mounted the footpath and crashed into him, leaving him critically injured.

"I had no idea how bad it was … it was touch and go and he was off getting X-rays. It was just a waiting game to see what wasn't broken," she said.

Leigh was still in hospital and while he was "doing well", he had a long way to go before he was back to his usual self.

Timmings said time would tell how Leigh's injuries would impact his future, but the active outdoorsman, keen snowboarder and musician was keeping positive and hoped to make a full recovery.

Acting road policing manager Kelly Larsen said the crash highlighted the potentially fatal consequences of driving at an "inappropriate speed" and while impaired by alcohol.

She said Leigh was "incredibly fortunate to be alive".

A police spokesman said the arrested man was due to appear in Christchurch District Court on Friday.

Timmings said she "wasn't surprised" when she found out where the crash happened.

"I've seen another car driving on that footpath before and it does almost look like a road; I imagine especially so if you're drunk."

Road dividers or barriers to clearly separate the cycleway, the road and the footpath were needed to keep pedestrians safe, she said.