Tokyo Olympics set for brutal road races

Expect even more brutal cycling road races at the Tokyo Olympics, even if they're safer than Rio.

Cycling Australia high performance boss Simon Jones says Tokyo's heat and humidity loom as key factors in the 2020 events.

There has been plenty of discussion around the courses for the road races, given the women's route leaves out a couple of key climbs from the men's event.

Regardless, Jones said they would be challenging races and he expected small groups to decide the medals.

"It will be hotter than Rio, believe it or not," he told AAP.

"It's going to be tough ... it could be absolutely brutal."

One positive from Cycling Australia's reconnaissance of the Olympic road courses is that they should be safer.

The Rio course was marked by a steep, technical descent in the closing kilometres.

Australian star Richie Porte crashed on that descent, suffering a broken scapula.

But he escaped lightly compared to Dutch ace Annamiek van Vleuten, who was left unconscious after a horrific crash while leading the women's road race.

Van Vleuten suffered spinal and facial injuries, but made an amazing recovery and she was back racing a month later.

Jones said the final descents for the two Tokyo road races were very quick, but safer than Rio.

"I don't think it will throw up as many left-fields as the Rio course did," he said.

Jones did not want to predict what sort of rider would win the Tokyo road races, other than it would be a one-day specialist who had focused on the Olympics.

He noted few would have had Belgian Greg Van Avermaet as their Rio men's winner.

"This is going to be open to the person who really targets it, who's really, really prepared," Jones said.

"There's a bit of bandwith there, for who could actually have success.

"It will come down to preparation; it will come down to specificity - I don't want to label it.

"It depends how you race it, as well."