The fuel gauge reads empty and the warning light is on. Ahead looms a petrol station sign.

But the forecourt is dark and fenced off, weeds crack the concrete and the pumps are long gone. Perhaps there is a sign announcing that the site will soon be luxury flats.

If the above scenario sounds familiar, it's not surprising. Since 2002, petrol stations have been shutting at an average rate of 600 a year.

According to trade body the Petrol Retailers Association, there are now fewer people selling fuel to motorists than at any time since 1912.

But with the cost at the pumps reaching an all-time high, doesn't this mean there's more cash than ever in selling "black gold"?

Not so, says Mark Bradshaw of the Federation of Petroleum Suppliers, a lobby group representing independent petrol retailers.

"Since 2000, we have faced a situation where the independent retailers cannot compete with the sites owned by major oil companies and the supermarkets."

There are two main issues facing independent retailers, who still make up about two-thirds of the 9,500 plus petrol retailers in the UK.

Firstly, independently-owned stations - many of which are branded with the name of major oil companies - must buy their oil from independent fuel wholesalers, adding another layer of costs.

The second problem, Mr Bradshaw says, is the sheer cost of petrol.

"Taxation accounts for about 75% of the cost of the fuel, and now petrol is costing retailers more than £1 a litre to buy in, this means the owner of a small forecourt with a 30,000 litre fuel tank needs to front £30,000 to keep it filled. That's a lot of money to pay up front. The cash flow implications for smaller operators are horrendous."

With typical profit margins of 2 to 3p a litre, it is the attached shop, rather than the forecourt pumps, that keep most filling stations in business.

A motorist buying £10 worth of fuel by credit card will actually be a net loss to a retailer because of card charges. However, if that motorist buys a chocolate bar when he or she fills up, a small profit will be made.

And the rise of the supermarket filling station - up from 11% of the market in 1992 to 38% in 2006 - hasn't helped. Other operators claim that the big supermarket chains sell fuel below cost price, creating a situation that is untenable for others in the market.

Supermarket bosses argue that they are increasing public choice and giving the motorist value for money.

"We aim to offer customers the best possible prices for petrol, and we regularly check our prices against competitors to make sure we are offering good value," a Sainsbury's spokesman says.

"In addition, to stay competitive within their own local market, individual petrol stations may adjust their fuel prices in response to local competition."

Comfort stops

Inflated property prices have also increased the incentive to forecourt owners - even the biggest operators - to shut down barely profitable stations and sell the land to developers.

Ray Holloway, chairman of PRA, says: "Motorists are now noticing gaps in fuel availability and if it gets worse, as expected, they will certainly be inconvenienced when searching for a forecourt in some areas."

The situation is particularly acute in Scotland, Wales, the West Country and rural areas of East Anglia, he says, but station closures are hitting cities, towns and the countryside elsewhere.

Mr Bradshaw, himself a former filling station owner, says that when forecourts close they leave more than just an ugly empty space. Many acted as the hub of the community, with the forecourt shop often being the village shop.

"Let's not under-estimate how useful it was to have filling stations everywhere providing a national network of toilet stops for long-distance travellers. Now most of them have closed, this represents a real issue for a number of travellers, particularly the elderly.

"And the environmental effect of having to travel extra miles just to fill your car is also considerable."

With electricity and other overheads rising at above inflationary levels, petrol sellers are lobbying the government for help.

They would like to see fuel duty reduced and the extension of a scheme, introduced by the Scottish Executive, where petrol stations can apply for grants to update their capital equipment.

They would also like to buy their oil before tax is added onto the price. Mr Bradshaw points out that each time a car drives off from a forecourt without paying, the filling station operator may have to pay more than £40 in duty on the tank of gas they received no money for.

Whatever drives independent petrol station owners out of the business, even non-motorists miss them when they're gone.