Quoting platforms and stations :
Fast trains can create a vacuum called a ‘back draft’ that can blow you over or suck you under a train.
How does that work ? I thought that the volume of air displaced by the moving train would, on the contrary, push one away from the train.
Best Answer
The front of the train compresses air which can blow you away, while at the back of the train air rushes back in after the train has displaced it. This backdraft is especially troublesome in closed areas such as subways, where a train exits a small tunnel near a platform and the displaced air rushes back into the vacated tunnel. Next time you see a big truck rushing by watch what happens to some grass or plants near the side of the road, you might be able to see the backdraft.