Tom Rusch has had enough.Stung by the exorbitant price of gas in recent weeks, the 27-year-old car salesman from Secaucus, N.J., is doing everything he can to avoid getting behind the wheel of his Ford Windstar."I'm trying to cut back on driving as much as possible," Rusch said, after spending $15 for 4 measly gallons of gas at a midtown fuel pump. "Public transportation is something I'm definitely considering, and I just bought a bicycle to use to go to the store near my house."Rusch is just one of countless area motorists turning their backs on cars—and opting instead for cheaper modes of transportation in response to the soaring price of fuel this spring.Ridership on trains and buses entering and leaving the city is way up. More people are taking to the streets on bikes than in years past. And drivers are spending less time on the road."People are definitely hurting," said Robert Sinclair, spokesman for AAA's Automobile Club of New York. "They are pulling from other parts of the family budget in order to buy gasoline."Sinclair said he expects New Yorkers to avoid driving expensive gas-guzzlers at all costs this summer.He speaks from personal experience. "My uncle has a $65,000 Lexus, but he's fighting with his wife over the used Toyota," Sinclair said.The average price of a gallon of regular gas in the city this week was nearly $3.20, according to AAA.A year ago, it was $2.37.As a result, there were more than 100,000 additional rides taken on Metro-North Railroad this March compared with last year, said Dan Brucker, a Metro-North spokesman. "Many New Yorkers can sniff at higher gas prices because of their incomes, but not so much anymore," Brucker said. "The higher fuel costs are definitely one of the factors fueling the shift."NJ Transit trains and buses also have seen an explosion in ridership. Since the beginning of April, there has been an increase of 41,000 more rides, said NJ Transit Chairman Kris Kolluri. In total, ridership is up 11% from last year."There is a strong correlation between rising gas prices and increased ridership on the mass-transit system," Kolluri said.Noah Budnick, projects director for the advocacy group Transportation Alternatives, said his organization did a bike count on all four East River bridges last week that found there were significantly more cyclists on the road this year compared with last. "The higher gas prices give New Yorkers a reason not to drive," he said.Nicole Hastaba agrees.Until a few weeks ago, the 25-year-old accountant had been driving from her home in Brooklyn Heights to her office in lower Manhattan. "But it was just becoming too much money," Hastaba said. "So I figured I might as well get the exercise and go for it on my bike."Your moneyWith Tom Rusch and thousands of others in Manhattan paying about $3.35 a gallon for gas, where does the money go?Distribution, retailing costs: 27 centsOil: $1.81Taxes: 67 centsRefining: 59 centsSources: Dept. of Energy, Automobile Club of New York