For one day, the roads belong to the bikes.

Sunday marks the 38th annual TD Five Boro Bike Tour, where approximately 32,000 cyclists have the streets of New York City all to themselves. The 40-mile tour guides riders through some of the city's most scenic neighborhoods, from the South Bronx to Red Hook to St. George.

The tour will cause over 50 road closures on Sunday, but Mayor Bill de Blasio touts the annual ride as a way to promote the health and environmental benefits of cycling in the city.

"I applaud its organizers and participants for empowering both experienced cyclists and new riders to hit the streets in support of free bike education," de Blasio said in the tour's official program.

This tradition began as a 50-mile tour in 1977 that started and ended in Queens. Then-mayor Ed Koch embraced the event as a city-wide bike tour the following year, increasing the number of participants from 250 to about 3000.

There are four start times in four different areas of the city on Sunday, but all scheduled road closures will begin at 7:15 am.

For more info, visit www.bike.nyc. (Stephanie Grella)