Several bystanders went to help Carolyn Ryk after she was knocked off her bike about 7.15am on Monday, but the driver did not stop.

Carolyn Ryk had time only to yell "unbelievable" before a car turned in front of her.

With no time to brake, she knew it would not end well, but there was nothing she could do.

Ryk hit the side of the car at the intersection of Greers and Northcote roads, Christchurch about 7.15am on Monday.

Two cars had indicated to turn right. The first car made it through in time, then the second driver made the "crazy" call to follow.

​READ MORE: Cyclist hurt in Christchurch hit and run

"I was quite close to it and I thought, 'there's no way this other person is going to do it', but they did. I just had to let it happen."

Several bystanders went to her aid, but the driver did not stop.

Ryk was taken to hospital with a broken bone in her hand and sore ribs.

"I'm counting my lucky stars that I've only got the injuries I have, it could have gone horribly wrong."

The vehicle involved was a beige-coloured Toyota Corolla wagon, or similar. Ryk wanted the driver to come forward.

"The decent human thing would be to come forward, face up to it.

"I think that's pretty stink, obviously their needs and whatever they were going through were far greater than mine."

Former lecturer in transport engineering Dr Glen Koorey said Christchurch was one of the safest places for cyclists in the country. He said about a fifth of all cycling throughout the country happened in Christchurch, but only one sixth of the injuries and about one seventh of the fatalities.

"That tends to suggest to you that what we've got already, in terms of infrastructure, is pretty good and we've got more to come."

There were 115 injury-causing crashes in Christchurch last year, including one fatal incident and 28 where people were seriously injured. Failing to stop was the main factor in crash reports.

Koorey said the figures were not surprising.

"If you add up the number of crashes in a year then surely that's a lot, but again that comes back to there's a lot of cycling.

"There's 50,000 cycling trips a day in Christchurch . . . you're eventually going to have a crash."

Christchurch City Council data showed 63 per cent of reported crashes involving cyclists were at intersections.

Koorey said the numbers stacked up nationally, with two-thirds of crashes at intersections.

"People often get worried about a car-going-past-you kind of crash, but that's not normally the biggest risk. It's the cars crossing in front of you at the intersections."

Monday's incident was the second hit and run in Christchurch in less than a week.

On Thursday, 34-year-old Duncan Robertson was knocked off his moped on the corner of Grahams and Wairakei roads. The driver of a silver sedan stopped briefly, then drove on.

Police would like to speak to the drivers in both incidents, along with witnesses or anyone with relevant information.

They are asked to call Christchurch police on 03 363 7400, or can call Crimestoppers anonymously on 0800 555 111.