A criterium is a bike race on a short, closed-circuit course, usually under a mile in length and lasting 30 to 60 minutes. Criteriums are great fun for spectators because you can walk around the entire course and see racers fly by every few minutes at nearly 30 miles per hour, in very close proximity to one another!The Littleton Twilight Criterium takes place on the streets of Historic Downtown Littleton with lots of corners, speed and action on the 0.8-mile course, and and featuring many of the best racers in the nation!