fwiw, I think the car barriers never had the purpose to stop cars, but to show people that at least on some level someone cares about their perceived safety.
At the weekend, I was at a small town which had a half a mile long main road blocked off for a market day. They put up bollards to do so.
Chances are, there were 0 persons planning a car attack on it. So there was an element of "We don't think anything's going to happen, but if it were to happen, we're prepared.". A bit like having a fire extinguisher when there's never been a fire.
But would seeing the bollards also have the effect of discouraging the insane people of the idea of driving the car through the crowds the next time a market day is held?
Oppositely, if they didn't put up any barriers, a psychopath seeing this and the realization that cars can be weapons might give them the idea of "I know what I can do for my act of terrorism..."
