A long drive to and from work can be expensive and tiring, and with poor public transport links or prohibitive season ticket costs it can often be the only option. But with car sharing you could halve petrol costs and reduce your carbon footprint while sitting back and relaxing for one journey in two.

The system can help even if you don’t drive — simply contribute to the driver’s fuel costs to enjoy a cheap cab ride.

More than 150,000 people are signed up to Liftshare.org, a free website that helps users nationwide to find others who want to make the same regular or one-off journey. Hundreds more have signed up to school-run.org, which puts parents from the same school in touch with each other so that they can share the school run Liftshare was founded by Ali Clabburn, 31, when he was in his final year at Bristol University. Sharing the journey from there to his Norfolk home with a driver friend for a contribution to petrol money meant a cheap, sociable road-trip. Mr Clabburn says: “A car with two people in it is twice as efficient. You save lots of money — and the planet.”

He says that the typical car sharer saves £1,100 a year in travel costs and spares the atmosphere one tonne of CO emissions. One Liftshare user, who shared his 32-mile journey to work with two other drivers, saved more than £15,000 over five years.

A useful first stop at the site is the cost calculator, where car owners can work out their approximate fuel and running costs for the year and to estimate how much sharing could save them a day, month or year.

If you want to get involved, register at the site to enter details of the journey you want to make — as a driver or passenger, or alternating as a driver and passenger. You may find immediate matches — around 35 per cent of users do. If not, details of your journey will be stored in the site’s database and contact details of compatible drivers or passengers will be sent to you as they are entered.

It is up to car sharers to negotiate what contribution to expenses the passenger should pay. Liftshare suggests that passengers and drivers split petrol costs or that each passenger pays the driver 10p a mile. No money need change hands where car-sharing commuters drive on alternate days.

The site is especially useful to source transport in the run-up to major events, such as Glastonbury, when thousands of drivers and would-be passengers tend to log on.

Mr Clabburn says that a trip from London to Glastonbury should cost passengers between £5 and £10, a substantial saving on most public transport. Events are likely to attract a like-minded crowd, so the journey becomes a chance to make new friends.

CASE STUDY: ‘I’m converted’

Angelo Squitieri, 40, signed up to Liftshare in the summer of 2005. He found no immediate matches and soon forgot about the website. Then, last August, the IT consultant was contacted by someone who lives a mile from his home in Nottingham and wanted to split the 110-mile return commute to Peterborough they were both making. Now Mr Squitieri and his car-sharing partner drive on alternate days, four days a week, each saving £20 a week on petrol.

Just as compelling as the saving is the chance to enjoy regular hassle-free journeys in his sharing partner’s Audi TT convertible. He says: “I’d definitely recommend it just for the cost saving. Then there’s the chance to take it easy half the time.”