It is a sunny morning in the Berkshire woodland and a small group of men and women clutching clipboards are lurking behind trees or amid the ferns, looking alert and expectant. Then the object of their attention comes into view: not a shy songbird or a rare mammal, but a cyclist clad in a fluorescent bib.

Followed closely by a small car, the rider stops by traffic lights at a road junction set somewhat incongruously amid the trees. Another bike-and-car duo rolls into view at the other side. The various lights turn green, and everyone heads cautiously on their way.

This is the test ground of the Transport Research Laboratory (TRL) near Bracknell, and the closely watched traffic flows are part of a pioneering project that could fundamentally change Britain's inner cities over the next few decades.

TRL, formerly part of the Department for Transport but now a world-leading independent research group, is conducting a £4m test programme for Transport for London (TfL) to see how Dutch-style cycling infrastructure, such as segregated lanes and cyclist-priority roundabouts, can be adapted to British road conditions.

Work has already begun to reshape some London roads and junctions, part of a grandiose £900m plan unveiled by Boris Johnson earlier this year. Campaigners hope other areas could follow suit, tilting life in urban Britain away from decades of car dominance.

The trial being observed that morning was for low-level, cycle-specific traffic lights set a couple of metres forward from those for cars, keeping riders ahead and visible. When they are introduced, the cyclists' lights will probably turn green a few seconds earlier than the standard traffic lights, giving riders a head start. Participants receive minimal information about what to expect and the TRL researchers keep out of view, hence the hiding amid the shrubbery.

Elsewhere on the vast TRL campus, a series of other bike-friendly layouts are being tested, including a "bus bypass", which places bus stops safely out of cycle lanes, a bike lane separated by intermittent "armadillo" reflective humps rather than a kerb, and, most ambitiously of all, a Dutch-style roundabout with a segregated gyratory flow for bikes. There is also a computer simulator in which people "drive" a real car around a bike-filled cityscape projected on to surround screens. The scheme has already used 2,500 paid testers and is seeking more all the time.

Such extensive testing is necessary, not least because innovations need regulatory approval, said Dana Skelley, director of roads for TfL. "Pretty much everything here is a layout that we're not permitted to have on national roads under the current legislation. We realised that if we wanted to attract more people to cycle, more safely and more often, it was necessary to create a more cycle-friendly environment, and we looked towards Europe for that."

Domestic road users were generally not familiar with all this, she added: "Just because it works in Europe doesn't mean it's going to be OK. We needed to understand how British drivers understand these new road layouts and how they behave."

This is particularly the case with the roundabout, where drivers have to learn that the circular flow of cyclists has priority, not only over vehicles joining the system, but those turning to exit.

Commenting on the first tests, Peter Vermaat, a TRL engineer, said: "The drivers don't really know what to do, so generally they give way to the cyclists. We've had some sudden braking a couple of times, but nothing worse."

The test site is the physical manifestation of a long-running campaign by cycle groups for infrastructure that is not just well designed but sufficiently continuous to tempt a wider range of cyclists – children, or older people, especially women – on to urban streets.

The message of the London Cycling Campaign's Love London, Go Dutch project seemed to have been absorbed, said Mike Cavenett from the group. "I always liken TfL to one of those enormous oil tankers. It's a big, £7bn beast with thousands of employees and it takes time to turn around. But it is turning. There is a change in attitudes."

He added: "I think TfL are realising that. There is still inertia, and some elements are still deeply conservative about the changes. But other elements get it."

While some Dutch-style infrastructure will arrive soon – a new section of London's previously criticised cycle superhighways is being built with segregation and redesigned junctions – other innovations could prove more problematic.

Chris Peck, from the national cycling organisation CTC, argues that Dutch-style roundabouts are reliant on traffic flows much lower than the 50,000 vehicles a day seen on some roads in inner London. "That's far beyond the advised capacity for a Dutch roundabout. It's far too high to allow priority over side roads," he said. "If you had a platoon of cyclists coming all at once, which tends to be how traffic moves, and they have priority over traffic trying to get off the roundabout, that could lock up the roundabout very quickly. They will only work along with measures to reduce motorised traffic."