Think the price of gasoline is your biggest problem? On the island of Manhattan, the problem is just finding a gas station.When the needle on Estella Fernandez's red Kia came dangerously close to "empty," she rolled down her window and hollered to a cab driver (who else?) for directions to the nearest pump.Try 10th Avenue and 34th or 37th Street, he suggested.Her coordinates at the time were 24th Street and Park Avenue South in Gramercy, 16 long blocks away. Fernandez, who owns a cleaning company, headed west and north to find a gas station with a line of yellow cabs reminiscent of the gas shortage days of the 1970s."It's terrible, terrible!" she cried, clutching her heart. "I was going around and around for 15 minutes."Gas stations are an endangered species in Manhattan, shoved aside by luxury developments and spiraling commercial rents. A cluster of stations sit on prime real estate that has already been rezoned from industrial to residential.In the past few months, at least four stations have been shuttered. That means there are no more than 54 stations left to service the estimated 830,000 cars, delivery trucks and various other gas-consuming vehicles that crawl through Manhattan's urban canyons each day. It's come to the point that the city's Planning Department is examining strategies to keep the remaining stations in business."I don't think they will disappear completely, but I don't see stations being built because of the expense," said Ralph Bombardiere, executive director of the New York State Association of Service Stations and Repair Shops. "I don't see anyone putting that kind of investment in it."The numbers tend to bear this out. The island is 23.7 square miles of real estate, home to about 1.5 million people. Add to that the tens of thousands of daily commuters, and land in Manhattan becomes what water is to Los Angeles: precious regardless of looks, smell or location.Scarcity explains, in small part, the borough's astronomical gas prices, says Bombardiere. Fewer stations equals less competition.New York has the second-highest gas prices — averaging $3.19 a gallon Sunday — in the contiguous United States, after California, according to AAA. Manhattan prices are even higher.A Gulf station near the entrance of the Brooklyn Bridge tested the boundaries of the market in April, when it briefly charged credit card customers $4.50 for a gallon of premium gas and $4.26 for regular.On Manhattan's dwindling gas station row along 10th Avenue, Karacsony Aletar sat in his cab across from the recently shuttered gas station on 27th Street and ticked off the names of three recently deceased stations. "Every place where real estate took over," he explained, his voice carrying a hint of his native Hungary.Up the street about half a mile, cabbie Thomas Wood waited in a queue for a pump. A black cap embroidered with "USA" shaded his stern face. "I have to come here because there's no gas on the East Side," he said, adding that the scarcity of stations cuts into his working time — and fares. "You're supposed to finish at 5, but if you finish at 4 you can find gas."Environmental activists happily point to the dying stations as proof that New Yorkers need other things besides gas. "The disappearance of gas stations shows that the market is right, that the real estate is valuable and it should be put to better use," said Paul S. White, executive director of Transportation Alternatives, a group that promotes cycling and walking. "We don't need to protect a gas station like an endangered species."The winners often turn out to be the oil companies, said Bombardiere, of the gas station association. They typically own the land and set the gas prices. And when they're ready to sell, the companies reap the rewards.The All Star Service Station is on a corner near the now-abandoned High Line elevated rail tracks, which are slated to become a park. Nialz Patel, the station manager, recently heard that there will be no new lease."The life always changes, and this is a changing, too. I have made money, it's all right," said Patel, who expects to shut down in a year.The city's Planning Department, which makes recommendations for rezoning and tracks demographic shifts, plans to examine strategies for preserving critical services, such as gas stations, in Manhattan, according to Rachaele Raynoff, a department spokeswoman. One option is to provide special zoning protection to gas stations, repair shops and other industrial-age service centers.Might New York one day protect gas stations because they provide a public service?Cornelius Burns thinks so. "You absolutely need gas stations," he says. "You would need to do something to protect it."Burns is both old school and new school when it comes to transportation. He drives his 1987 Chevy pickup truck to Pennsylvania to pick up horses and feed for his carriage company, which takes tourists on rides through Central Park. Burns said he spends $165 on gas on each trip. But whattayagonnado, he says. "You're not going to feed a horse out of a Manhattan grocery store."