The fun comes with some trade-offs.

While the nation’s best cyclists zip around courses in Lawrence and Perry Lake in Jefferson County this weekend, commuters may have to take detours Friday morning.

To make way for the Team Time Trial of the 2007 USA Cycling Collegiate Road National Championships, Kansas Highway 10, or the South Lawrence Trafficway on the western edge of the city, will be closed from 8:30 a.m. to 11:30 a.m. Friday.

This will be the third year in a row that the championships are in the Lawrence area. Next year they will be somewhere else.

About 500 cyclists from universities across the country will compete, including Kansas University’s club cycling men’s and women’s teams.

Event planners also expect 3,000 to 5,000 fans – who are familiar with the action – to cheer on cyclists as they race around downtown Lawrence streets Sunday morning.

“Having it occur (in Lawrence) three consecutive years certainly worked to the event’s benefit,” said Andy Lee, a USA Cycling spokesman.

Racing begins at 8:30 a.m. Friday with the Team Time Trial on the South Lawrence Trafficway. According to the Kansas Department of Transportation, traffic heading west out of Lawrence on Sixth Street or U.S. Highway 40 can only access K-10 to the north. Local traffic and residents who need access to intersections along the closed section of K-10 can be directed to cross by Douglas County Sheriff’s officers or Kansas Highway Patrol troopers.

Planners expect near perfect weather for the Road Race beginning at 8 a.m. at Perry Lake.

Sunday’s Criterium races begin at 7 a.m. in downtown Lawrence, where Massachusetts Street from Seventh Street to 10th Street will be restricted for most of the morning, including Vermont Street between Seventh and Eighth streets and New Hampshire Street from Eighth Street to 10th Street. No one will be allowed to park along the race route after 2 a.m. Sunday.

Race volunteers will be available to direct people to safely cross streets downtown.

Most cyclists and race workers are scheduled to arrive today in Lawrence. The event’s headquarters is at the Lawrence Holidome, 200 McDonald Drive.