The head of a group representing more than 200 business and other organisations with major operations in London says she is opposed to segregated cycling infrastructure – because she believes it will lead to crashes between faster cyclists and those who are slower on two wheels.

Baroness Valentine, chief executive of the not-for-profit advocacy group London First, also defended its opposition to Mayor of London Boris Johnson’s flagship East-West and North-South Cycle Superhighways, currently under construction.

In an extensive interview with the Guardian's Dave Hill, she drew a parallel with the Congestion Charge Zone introduced by Johnson’s predecessor, Ken Livingstone, saying that in neither case had the impact on the city’s traffic been fully addressed prior to the projects being implemented.

“We’ve found it very difficult to work out what the real consequences of the cycling superhighway are for congestion,” she said. “It’s precisely what Ken did when he first put in the congestion charge in.

“He took a load of road space out for buses – which with hindsight turns out to have been a very good thing – and he took a load out with pedestrian schemes, and before you could blink you were back nearly to the same level of congestion as before the congestion charge began.

London First was joined in opposing the Cycle Superhighway plans last year by the likes of property company Canary Wharf Group and the Licensed Taxi Drivers’ Association, with one of the chief areas of concern being the impact of the infrastructure on journey times for motor vehicles.

Transport for London (TfL) presented its own figures of forecast delays for a variety of journeys to attempt to address those concerns, but opponents remained unimpressed, and Valentine continues to harbour misgivings.

“We’re now going back to gridlock,” she said. “I think it’s incumbent on the GLA and TfL to just be sure that they are taking everybody’s concerns properly into account. I’m not clear whether that’s being done.”

In October, responding to criticism of the project by Canary Wharf Group and others, British Cycling policy advisor Chris Boardman noted that the Cycle Superhighway proposals enjoyed support from businesses and other organisations such as NHS Trusts across the capital, and described opponents as “old men in limos.”

It’s an accusation that Valentine rejected as “rubbish,” adding; “TfL ought to be better at listening to customers, cyclists and all people on the roads.

“As a cyclist, you do get very angry about the way the traffic treats you, that cars cut you up and buses get in the cycle lane.

“Part of the reason cyclists have got so aggressive is that they’ve been so badly treated for a long time.

“When one of them gets killed on a junction where TfL has been told several times it’s unsafe, that’s not a good place to be. Quite a lot of your big picture answers to road problems actually come just from listening, talking and finding out what really does and doesn’t work.”

She told the Guardian that she has been cycling in Central London since she was 14 years of age but insists that physically segregated infrastructure will not improve cyclists’ safety – instead, she fears it will make matters worse.

“I’m a tootling-across-Central-London cyclist as opposed to a superhighway sort of cyclist,” she revealed.

“I’m not interested in segregated lanes. You are being herded like cattle. I’m about the slowest cyclist in London and I always think the thing most likely to knock me off my bike is another cyclist going very fast right at my elbow.

“That would be more of a worry in a segregated lane. I suppose they are meant to prove you’re taking cyclists seriously.”

Besides Canary Wharf Group, London First’s membership list includes a number of organisations that backed the Cycle Superhighway plans through the Cycling Works website.

Those include Royal Bank of Scotland, which has 12,000 employees in London, the law firm Allen & Overy, property owners The Crown Estate, and professional services firm, Deloitte.