If you're driving through the center of Miami tonight, you need to take a close look at the map below.
The monthly group bike ride called Critical Mass is taking place again. Cyclists (many in costume for Halloween) will be riding 12.5 miles around Miami starting at Government Center and ending at Grand Central Park.
The Miami event usually draws a couple thousand cyclists and can back up traffic. The route also changes every month.
Cyclists joining in Fort Lauderdale's Critical Mass have a 14-mile route planned that will start at the War Memorial Auditorium.