The M4 in Newport is one traffic bottleneck

The free service was launched as part of Green Transport Week and it is hoped that people making the same journey will be able to share cars and costs.

The South East Wales Transport Alliance (Sewta), which represents local councils is behind sewtacarshare.com.

Under the system, commuters can link up with others making the same trip.

The free service promotes itself as linking people making journeys to work and shopping, as well as sports events and concerts.

It works by registering personal and journey details to the website database, which will then send information about others making the same trip and giving you the opportunity to contact that person.

It would be a big wrench to have to go back to commuting alone John Betts, car sharer

As part of the scheme, businesses are being invited to take part with the incentive being that car sharers get priority parking.

Sewta chair Tom Williams said: "Car sharing is kind to the environment and your pocket.

"Everyone benefits from car sharing - those doing it can cut their travel costs, other road users gain by the reduction in congestion and it also contributes to the fight against global warming."

John Betts, 58, who works as a senior examiner at Newport's Patent Office has been car sharing for around 10 years after the organisation moved its headquarters from London to south Wales.

"One of my colleagues suggested it so we agreed to try it on a month basis and we are still doing it," he said.

"In fact, there are three of us who do it now."

Mr Betts who lives in Monmouth said that the benefits of car sharing outweighed the negatives.

'Big wrench'

"We save money because we are only driving one week in every three and driving can be pretty stressful so if you are not driving it gives you a chance to unwind after work.

"There are benefits to the environment obviously and it is quite a sociable thing to do."

But there were some disadvantages to the scheme too.

"We all live in Monmouth and work in the same organisation which is a great help but it still adds about 15 minutes each way in travel time and of course you have two others to take into account.

"So when it is a sunny day and if you're working flexi-time and finishing a bit earlier, then you have to think about them.

"But to be honest, it would be a big wrench to have to go back to commuting alone."