By their nature, road time trials and road races means that the riders are out of site of the stationary public for a lot of the race. There becomes an issue of how you can keep them informed and try to encourage them from trying to continually get ahead of the race so they can see the riders pass another point on the road.
Riders blatantly ignoring the rules of racing and the rules of the road don't just put themselves in danger, they put other riders and other road users in danger. They also put at risk the future of road racing. When racing is held on open roads as they were over the weekend, the riders effectively have only the left-hand side of the road to race on (in New Zealand, we drive on the left). Crossing the centre line should be considered the same as taking to the grass on the side of the road. It hinders your progress and of course puts you in the path of oncoming traffic. This can irritate other road users who then put pressure on councils to ban road racing.
For road races, a major role of the commissaire is knowing the state of the race at all times. This can prove quite difficult when there are riders attacking off the front of the peloton (the main group of riders in the race) and others having mechanical failures or punctures. In all major road races, there is a convoy of officials, selectors, media representatives, and support vehicles that need to be managed. All this falls upon the team of commissaires to manage. The task can be quite demanding depending where you are on the road.
Even as a finish line judge or time keeper, you want to know where the riders are during the race. Each lap, you attempt to record all the race numbers and the time gaps. This makes it easier when the race finishes to check that you have accounted for all riders and that lapped riders are not accredited with incorrect placings. Lapped riders are often pulled from the event so that they don't hinder the main race leaders. You can also communicate with the on road commissaires about where riders are or which riders have withdrawn from the race. It is also possible that you can then update the public on the state of the race. Supporters always want to know where there rider is. Was (s)he at the front of the race or has (s)he been dropped and floundering at the back of the race. Fortunately, we had the support of a team focused on informing the public.
If you don't keep track of how the race is unfolding, when it comes to the finish, you have no idea how many riders to expect in the sprint or even to finish. We had a little bit of a problem with this on Sunday because of difficulties with radio reception. Still at the end of the race, we had a fairly clear idea of which riders had withdrawn and where key riders were on the road. If you don't know this you can end up standing on the side of the road waiting for the last rider and not being sure whether there is actually a last rider.
The commissaire's role is quite challenging and there is always something new to learn at each even. Unfortunately, there are also riders that you have to talk to because they are so focussed on getting a good time or finishing as high up as possible that they forget that there are rules for racing and of the road that they need to follow. As a commissaire, the first role with respect to rider safety is one of educating the riders. Most of this is done through attending club and regional events. Here when you see riders doing stupid things on the road, you can go and talk with them and help them to understand why their behaviour wouldn't be tolerated at the higher levels of the sport.
The top commissaires have a real love for the sport and also have a really good working relationship with the riders. The don't like having to be enforcers of the rules but know that if the racing is to be fair, safe, and enjoyable that they need to do so. In the same way, they enforce the rider uniform codes because these help the public, promoters, and sponsors. The right uniform helps the public know who is part of which team and for promoters and sponsors, it is all about getting their value for their dollar. All sponsored sports people are advertising billboards and to ensure that sponsorship is retained in the sport then keeping the sponsors and promoters happy is a key part of the sport persons activities. Portraying the right image through what you wear on the bike and off the bike helps portray a concern for your sponsor. The same applies for following the race and road rules. A sponsor doesn't want their name associated with bad publicity.
In the end, commissaires and all officials at events are interested in promoting the sport.