Cycling campaigners fear more deaths or injuries in downtown Auckland unless an off-road bikeway being built through Grafton Gully is extended to the waterfront.

On Tuesday I arrived very early on the scene of a cycle versus truck fatality in Auckland, writes Lance Wiggs. The sight of a person lying motionless in the street with mangled bicycle in the background is chilling enough.

A study for Auckland Transport has calculated the "social cost" of cycle crashes for the region's biking routes.