Bike users fear new cycle lanes proposed for Wanstead will not improve safety unless drivers change their behaviour.
Lanes could be introduced in Cambridge Park, between Blake Hall Road and St Mary's Avenue, to link with existing ones leading to the Green Man roundabout.
It is hoped they will encourage people not to cycle on pavements, but they will only be 'advisory', which means drivers can still use them, including for parking.
And a cycling campaigner warned this poses a significant hazard.
Chris Elliot, 57, of Wanstead Park Avenue, is a member of the Cycling Liaison Group.
He said: "If the cycle lanes are properly designed, they can be of assistance, particularly to less experienced cyclists.
"However, because it is not illegal for cars to park in them the danger comes with getting around those cars.
"What you don’t want is to keep swinging out into a stream of traffic – sometimes it is best to ride in a straight line from A to B out of the lane - motorists need to understand that, rather than get annoyed by cyclists."
Tom Ali, of shop Bike Trax, regularly cycles to work.
He said: "I don’t think they will make much difference. The lanes would be better put on the pavement, but that would probably annoy a lot of pedestrians.
"What does need to change is motorists attitudes to cyclists. I have been cycling in the forest before and cars have just pulled out on me."
It is estimated the lanes will cost around £8,000, funded by Transport for London.
A council report said: "The provision of cycle lanes will have the potential to reduce the level of illegal cycling on the footways of Cambridge Park, further enhancing the quality of life of residents and other footway users."
The proposals are due to be discussed by councillors on Monday at the Area One Committee meeting in Wanstead Church School.
Officers have recommended the scheme be approved.