A path upgrade on the Goodwill Bridge is being urgently investigated after cyclists were left skidding and with little traction when the surface was wet.

The Goodwill Bridge path was upgraded recently with new signage and a higher speed limit for cyclists, along with a new blue path in the middle.

It was understood the blue surface, while not a dedicated bike lane, was designed to encourage pedestrians to walk on the left and right-hand side of the bridge, keeping the centre clear for cyclists.

The new surface on the Goodwill Bridge has proved slippery for cyclists when wet.

But the rain in Brisbane on Monday was bad news for cyclists riding on the blue Goodwill Bridge path as they found they lost traction.