More and more New Yorkers, including Brooklynites, are bicycling across the Brooklyn, Manhattan and Williamsburg Bridges than ever before, according to the bicycle advocacy group Transportation Alternatives.Some might say it has to do with the price of gas, which is about $3.25 a gallon, as opposed to about $2.25 a gallon at this time last year. Others say that many people started biking on a regular basis during last year's short-lived transit strike and never stopped (the strike saw a 500 percent increase in bicycling to work).While both are true, the increase in bicycling, both as a hobby and a way to commute, is part of a long-term trend.According to Transportation Alternatives, spring morning bike riding across the four East River bridges (including the Queensboro Bridge) is up 35 percent compared to a year ago and up 100 percent compared to four years ago.Much of the steady increase in bicycling can be traced to the increase in places to bike. As recently as 25 years ago, just about the only places to bike in the borough, other than in the street where riders have to compete with drivers, were dedicated bike paths (the original "greenways") such as the ones on Ocean Parkway, Shore Parkway and Eastern Parkway.The one on Ocean Parkway, dating from 1885, is the oldest bicycle path in the country. Then, the city started installing dedicated bike lanes, especially in Downtown and Bay Ridge streets, but also elsewhere (the longest is on Bedford Avenue). While these lanes are often ignored by motorists, the fact that the city recognizes the cyclists' needs is a step forward.As recently as 10 years ago, only the Brooklyn Bridge had a working bike path, which cyclists share with pedestrians. But since then, the bike paths on the Williamsburg and Manhattan Bridges have been rehabilitated, and are used regularly by Brooklyn commuters.Recently, the city Department of Transportation (DOT) has installed a bike path on Tillary Street, improving bicyclists' access to the Brooklyn Bridge.And for some time, an effort is under way to build a "Greenway," stretching from Sunset Park to Brooklyn, which will be shared by pedestrians and bicyclists alike. The project is being supervised by the Brooklyn Greenway Initiative, which recently acquired $18.25 million in federal transportation funds. Much of the work in Greenpoint has already been done, and plans for Brooklyn Bridge Park include space for the Greenway. In addition, the Brooklyn Navy Yard has agreed to move its fences in to accommodate the Greenway's right-of-way."New Yorkers want to bike," says Noah Budnick, deputy director of Advocacy for Transportation Alternatives. "And, everything the city does to improve cycling, make biking easier and more convenient and make our streets, greenways and bridge paths safer and more inviting encourages more New Yorkers to ride more often."Breaking It Down, Bridge by BridgeIn 2005, the city removed the dangerous metal "bumps" on the Williamsburg Bridge. As a result, this April, the Williamsburg Bridge saw a whopping 84 percent increase in bike riding compared to a year ago.The two Downtown Brooklyn bridges — the Brooklyn Bridge and Manhattan Bridge — saw a 25 percent increase in cycling. While the Manhattan Bridge saw a slight decrease in morning bike crossings (-16%), bike riding across the Brooklyn Bridge increased 62 percent during the morning rush.Advocates anticipate that, if current trends continue and the City continues to encourage cycling, making it safer, easier and more convenient, daily bike riding in New York could hit a record 150,000 cyclists in 2006.As an added indicator of interest in bicycling, the DUMBO-based Recycle-a-Bicycle Program, which teaches students to take apart and repair bikes, now has programs in one high school and four middle schools."Interest in the program has never diminished in any of our schools," says a spokeswoman.