To go around the barrier you have to drive over the rails without help of the crossover. Doesn’t always work, vehicles get caught on the rails often when this is tried.
If it was an attack, why 3 people in the truck? Only need one to drive. Why place the truck on the tracks on purpose and then sit in it and wait get smashed with 3 people?
It’s not fishy.
I would have used a cement truck