Auckland Transport is replacing a slippery white line near the spot where a cyclist was killed on Tamaki Drive last year, after reports of two accidents in a day caused by skidding.

Recreational cyclist Jim Tabak broke a shoulder blade on Tuesday when a companion skidded on the line and toppled on to him on a tight left-hand bend near Kelly Tarlton's Underwater World.

He said several other riders in his Mt Eden Cycles group crashed into them, but slow-moving motor vehicles were able to stop in time so nobody else was injured.

And Mt Eden Cycles owner Mark Taylor said a member of another group of riders associated with his shop crashed at the same spot and broke a collar-bone about half an hour before Mr Tabak was injured.

He had also heard of another crash last week.

Mr Tabak said he also slipped last week on the white line, which is on the outside of a narrow green bicycle lane, although he managed to stay upright on that occasion.

The bend is across the road from a pinch-point on Tamaki Drive where 27-year-old English nurse Jane Bishop was killed in November, after she allegedly swerved to avoid an opening car door and was hit by a truck while cycling towards Mission Bay.

Auckland Transport moved swiftly then to remove four parking spaces on the seaward side of the road to create more room, after an allegation that the former Auckland City Council ignored a warning from a cycling advocate about the pinch-point four years earlier.

Mr Tabak, who reported his crash to Auckland Transport, said he was relieved it had promised to quickly replace the white line, which was particularly slippery in wet weather.

Road corridor operations manager Andrew Allen told him in an email on Thursday that he had asked a staff member to visit the site and ensure a non-slip surface was applied "by the end of next week".

But after Cycle Action Auckland said more-urgent attention was needed, Auckland Transport communications manager Wally Thomas told the Weekend Herald a contractor would start replacing the line today.

Mr Thomas said the task would take at least two days, even in good conditions, and his organisation would do its best to finish by Monday.

But he could not guarantee that, as dry weather was needed to lay the new surface in place of an existing therma-plastic composition.

He said it was ironic the white line had been laid to delineate the cycle lane in order to improve safety.

Road markings elsewhere along Tamaki Drive would be checked for skid resistance.

Cycle Action Auckland spokes-woman Barbara Cuthbert praised the transport organisation for a "reasonable response" to what appeared to be a serious hazard.

But she said other dangerous spots on the road needed prompt attention.