I watched footage of Contador's attack on Verbier in 2009 and it didn't seem too bad, there were a few fans on the road but they didn't disrupt the race.
Most of the fans did follow the general rules and most people with flags ran behind the rider and only when they were riding solo or in a small group. The few who ran ahead were some distance from the rider and moved aside or off the road when the riders got closer.
It helps that it was on an 8% incline and the riders were doing 20km/h.
I guess it's a small number of fans that ruin it for everyone.
Most of the fans did follow the general rules and most people with flags ran behind the rider and only when they were riding solo or in a small group. The few who ran ahead were some distance from the rider and moved aside or off the road when the riders got closer.
It helps that it was on an 8% incline and the riders were doing 20km/h.
I guess it's a small number of fans that ruin it for everyone.