Teams have been warned by organisers that they would have to drop out of the race should two of their members test positive or show strong symptoms of COVID-19.
Whether the Tour de France will celebrate a winner this year is anyone's guess as the world's greatest cycling race starts in Nice on Saturday amid fears of a 'second wave' of COVID-19.
New coronavirus cases have been rising at an alarming rate in France since the beginning of the month, casting a menacing shadow over the re-scheduled 107th edition of the race.
Coronavirus tests will be conducted in a mobile unit throughout the three-week race, which will go through southern, western and central France, the Pyrenees and the Alps and include eight mountain stages.
Riders will be tested six and three days before the Grand Depart in Nice. Any individuals who test positive along the race will be isolated while contacts between the teams and Tour followers -- media, fans and organisers -- will be strictly restricted.
Teams have been warned by organisers that they would have to drop out of the race should two of their members test positive or show strong symptoms of COVID-19.
Testing riders regularly has been an expensive exercise for the cycling outfits, with Groupama-FDJ doctor Jacky Maillot saying it has cost them 130,000 euros ($154,000) for the season.
Fans on the road could also be a danger if they do not abide by the protocols that have been put in place, although no rider scheduled to take part in the Tour has tested positive since racing resumed last month following a four-month suspension.
"So far cycling has not tripped on any obstacle," Tour director Christian Prudhomme told Reuters.
"There will be police officers on the climbs, who will filter the crowd and make sure fans are wearing masks since I'm confident all the local authorities will make it mandatory."
Spectators along the road will have to adhere to the two-metre social distancing rule and they will not be allowed anywhere near the team buses at the start of the stages.
The August 12-16 Criterium du Dauphine, which served as a dress rehearsal for the Tour, was completed without a glitch but the scale will be much bigger on the 21-stage Tour de France which concludes in Paris on September 20.
Prudhomme said the Tour would not be stopped if there were positive cases in the peloton, leaving it instead to regional health agencies to advise on the way to proceed.
"The Tour de France will not stop if there's a positive case, even if nobody knows whether it will be completed or not," said International Cycling Union (UCI) president David Lappartient.
