Racers scrambled over the level crossing as the barriers came down, in violation of the safety rules of both the race and train company – while one cyclist was struck by the closing barrier.

"Ooooooh, get across if you can, because the 7.13 to Paris is about to stop the peloton," one commentator says cheerfully.

The TGV, of course, is famous as France's high-speed rail system, one of the fastest on earth with speeds of over 300kph.

Thankfully, the driver showed more sense than some of the cyclists and slowed down before he got to the crossing - those top speeds are not for open tracks.

SNCF, the French train operator, is calling for police to prosecute over the breach of safety rules - which was broadcast live on television.

Ordinarily, breaking a level crossing could lead to disqualification. However, given the fact that the barriers fell while the peloton was crossing - and at least one racer was actually hit by it - authorities took no further action.

“In theory, those who pass when the barrier is down are thrown out of the race," one of the race commissioners told Velonews, saying that the peloton did not have time to safely stop.

"This time, that would have been unjust in respect of those riders who weren’t identified.”

The Paris-Roubaix road race has been taking place since 1896, and takes place over historical roads.