Friday is National Bike to Work Day, and to celebrate, Transportation Alternatives will have coffee, snacks and commuter bags for cyclists at six locations — two in Manhattan and four on East River bridges.

T.A. will be educating bicyclists about civic riding on NYC streets, and helping riders team up with buddies who share their commute.

This year, the NYC Department of Transportation will be leading an escorted ride for bike commuters from Brooklyn’s Grand Army Plaza to Midtown Manhattan. Led by DOT Commissioner Janette Sadik-Khan, the ride will stop at T.A.’s City Hall bike commuter support station, where bike commuters from across the city will gather to celebrate National Bike to Work Day at a press conference.

TA’s City Hall presser is scheduled for 8:00. See the Bike Month NYC web site for a complete calendar of upcoming events.

TA estimates that 185,000 New Yorkers commute by bike each day. DOT found that city bike commuting increased by 35 percent between 2007 and 2008. 

Follow the jump for specifics on all of TA’s commuter support stations, and be ready to tell everyone about your ride in tomorrow.

Update from DOT: The Sadik-Khan ride will begin at Grand Army Plaza and Union Street, departing at approximately 7:30 a.m. All are welcome.

• City Hall Park, corner of Chambers and Centre Streets
• Williamsburg Bridge, landing at the top of the incline from the Bedford Avenue entrance
• Queensboro Bridge, entrance to the bike path, Queens Plaza North and Crescent Street
• Brooklyn Bridge, beneath the Brooklyn tower, mid-bridge
• Manhattan Bridge, plaza at Manhattan entrance to the bike path
• Madison Square, pedestrian plaza at Broadway and 23rd Street