A new generation of road camera which can deduce how many people are in a car is to be tested for the first time.
Schemes are already running in Birmingham and Leeds
It will initially be used to monitor car-sharing lanes in Leeds, but councils across Britain are said to be interested in using the technology.
Four out of five cars driving into cities at rush hour have only one person in them.
The government believes encouraging people to share journeys will help combat congestion.
It wants councils to look at building more "high-occupancy vehicle" lanes.
Enforcing the lanes has previously been a problem. In the US drivers often trick police and cameras with dummies and even large dogs to allow them to use lanes reserved for more than one person.
The new camera, developed at Loughborough University, can see how many people are in a car by detecting water and blood content.
The technology could lead to a big increase in the number of car-share lanes on British roads.
The inventor of the camera, Professor John Tyrer, believes the camera is key to reducing congestion.
"It allows you to automatically count people. That means you can sort out the congestion on the roads now the lanes now actually work properly," he said.
"That pools through to the congestion charging so they can charge differently or reduce the rates dramatically if you've got more people in the cars, and the same with car parking."
Car-sharing lanes are already in operation in areas of Birmingham, Leeds, Bristol and North Somerset.
In Birmingham - on the A47 Heartlands spine road - only cars carrying at least two people are allowed to join motorbikes and cycles in using the lane, in a bid to ease congestion into the city centre.
Work is currently taking place on the M1 in Bedfordshire and Hertfordshire to widen the road for a car-sharing lane.
Roads minister Rosie Winterton welcomed moves encouraging car sharing.
"We're certainly encouraging local authorities to look at innovative solutions to the problems that are created by congestion," she said.
"High-occupancy vehicle lanes can be part of that because they certainly encourage car sharing. It also contributes to improving the environment and can cut the cost of travelling as well."
But Edmund King, president of the AA, said that in practice, car sharing does not work.
"Most of us today work flexible hours. We don't go to work or come home from work at the same time," he said.
"Plus they're incredibly difficult to enforce, and if not many people use them they're actually a waste of road capacity."
Read a selection of your comments on this story:
I have given up using the scheme in Leeds as it simply does not work. The time saving over drivers in the 'one person' lane is often minimal. Government and Councils need to be investing their efforts into public transport rather than wasting money on policing us yet more. I would happily use the buses or trains to get to work if there was an adequate service.
Chris, Leeds, Uk
Why don't they market car sharing, convince people to do it rather than trying to force us to. Just a waste of money Could be spent on trying to improve our infrastructure for everyone rather than wasting a lane of a road, making the congestion worse for the others.
Daniel, Isle of man
I used to share a car, and was fed up of waiting for fellow car-sharers who didn't seem to have a home to go to, and would keep you waiting like a taxi-driver. I often waited up to half an hour waiting for them to show. I was glad to get back to my individual freedom.
Peter Woodier, Manchester, UK
Will this country stop being obsessed with spying on its citizens once and for all. Camera, Camera, Camera!!! I'm fed to the back teeth with councils and government using technology to increase its annual revenue. Maybe we should put cameras in government buildings and see what they really get up to with regards how they are spending our money
duncan mcdonald, Manchester
I am a widow on a pension. The only way I can get to see my sons is to drive up the motor way. There is no one else to go with me, so now I am to be penalised for visiting my family on a Sunday once a month?
Mrs.E.N.Ruffewll, London, England
I car share with 2 workmates on a 80 mile round trip which saves me money and driver fatigue as i work shifts plus it is also environmentally friendlier.The awkward bit is the actual meeting place for us where we can leave our cars securely.As i live in sheffield i see the supertram park & ride scheme working extremely well.Why on earth cant we provide 24 hour park & share scheme for the motorways where we can all meet and leave our vehicles securely.Iam sure more people would car share thus relieving the amount of 1 person car journeys on our major roads not just at peak times but all times.Maybe even the motorway services could provide a similar sort of service.
I have both taken part in a car sharing scheme, and therefore been able to use the dedicated lanes where I live. It works well on many levels. I save on petrol money, increase my social networks, have someone to natter with on the way to work and back again, get to work quicker, don't have the stress of having to drive all the time...I could go on. It really is a no-brainer. I would challenge the AA to come up with ideas that DO work, instead of constantly complaining about the unworkability of current efforts to solve the problem.
Fred Ehresmann, Bristol, Uk
This misses the point. I use my car precisely because at the start and end of a busy day, I don't WANT to mix with others who smell of last nights alcohol or garlic or the stinking cigarette they had on the way to the station. JBPriestly wrote something like "we are not all bees mixed up together". Our democratic representatives should start looking after the needs of all of their people and find ways to safely enable all activities rather than control their electorate.