Rolling road closure, usually enforced about 15 mins before the actual race appears.
Forward announcer is about 10 mins in front of the race, he stops at intervals and tells the crowd what is going on with the race, then there’s yet more NEG motorbikes, forward convoy (often including judges and maybe VIP guests who will leapfrog ahead to sprint points etc), then the race, then the rear convoy of team cars, Commissaires, more motos and eventually a rear police presence to lift the road closure. Depending on the terrain the road can be closed for up to 30 mins. Plan well ahead, get there in advance and park up.