ROTTERDAM, Netherlands -- During last year's Tour de France, there were no positive doping tests after three straight years when drugs cheats marred the event.
Pat McQuaid, head of the world cycling governing body UCI, estimates 400 to 600 doping tests will take place during the three-week race starting Saturday.
McQuaid hopes the tests deter cheaters and make for a clean 2010 race.
Anti-doping advocates say that tougher laws, more frequent testing and UCI's new biological passport program to track cyclist's physiological profiles have helped.
But arrests and signs that in-competition checks fail to catch some cheats show there's still a problem.