Plans to build two new cycleways across London have been given the go ahead.
Transport for London (TfL) approved mayor Boris Johnson's plans, which will see cyclists segregated from traffic.
Opponents of the £160m scheme have said it would take too much road space, meaning congestion would increase.
London First, London Travelwatch, City of London, Canary Wharf and the London Taxi Drivers Association have all voiced concerns.
If a judicial review is not launched by opponents as part of the consultation process, then work would start straight away and the routes could be open next year.
The east-west cycleway, which is being billed as the longest segregated route in Europe, will include a section on the Westway flyover where one lane will be removed to create a cycle track.
TfL said it hoped the number of cyclists on the road would treble.
Howard Dawber of Canary Wharf Group said a decision about taking legal action had not yet been made.
The management group has concerns traffic will be displaced. Mr Dawber said it would consider what TfL "are now saying - that they will review the scheme as it is implemented".
The leader of the Liberal Democrat London Group, Caroline Pidgeon, said: "I am certain that in a few years' time we will look back in amazement at the fuss that has been created over the Cycle Superhighways.
"The debate over the Cycle Superhighways is now over. TfL must now get on and build them as soon as possible."
Mr Johnson said they would be delivered as quickly as possible.
Sir Peter Hendy CBE, London's Transport Commissioner, said: "There will, naturally, be some disruption due to these works but we have some of the world's leading highway and traffic engineers, traffic models and modellers working tirelessly to ensure that this is kept to a minimum."
But Baroness Jones from the Green Party said the city needed more superhighways.
"London is now starting to get the cycle infrastructure it needs, but the pace of change is painfully slow and the lack of ambition is criminal."