I'm sure everyone has now viewed McNish's crash at LeMans. The point is that when things go wrong, no one can predict the outcome or consequences.
And when the s--t hits the fan, you need a robust, simple, proven, and flexible method of controlling the resulting chaos and restoring order. And it makes sense to keep things as simple as possible and avoid adding extra layers of complexity to a crisis.
For example, just look at the basic tool for extinguishing fires, the CO2 extinguisher, It's just a gas bottle, a valve opened by a simple handle locked by a pin. Some have a pressure gauge to monitor capacity, but that's all there is to it.
And because it is simple, it is reliable and works.
The safety car is a well proven method for controlling a pack of aggressive drivers, they have no choice but to slow down and follow.
You never know what an accident may bring, the result could be a ruptured fuel cell that drenches spectators, causing them to be in flames, and running all over the place. That's pretty freaky and weird, but you can't rule out this kind of horror scene.
Then all of a sudden, you are relying on some complex electronic signalling system to control the cars? What if the data is incorrect and some driver following his delta comes over a crest to discover three or four marshalls attempting to fight a fire in the middle of the track? I'm not willing to risk other's lives when a simple and effective method now exists.
The safety car goes out, everyone slows down, that's it, control established and maintained.
Now there's an additional benefit from creating a train, and that's the speed of cleanup and restoration. With a train, once it passes everyone involved in the cleanup has a pretty good idea of how much time they have before the train comes around again. That way, a team of four people with push brooms can sweep a decent section of track clean. But if they don't know where or when the next car will come zipping by, it will take much, much longer. In fact, a job that might take 90 seconds with four men may inflate to 30 minutes, and in a shoddy and haphazard manner.
A proud Canadian, and yes, HOCKEY is our game.