Could someone tell me what the picture shows? I tried with checkpoint, but I couldn't find further information.
It isn't quite clear from the picture what it is, and that is relevant because it depends on the purpose of the structure. For example, it could be a tollbooth on a motorway, or it could be a security checkpoint at a border. These type of barriers are used in various ways. Checkpoint implies that some kind of procedure is involved, for example showing an identity card. This wouldn't be the case with a tollbooth where a simple exchange of money happens. In other words, a checkpoint is a place where something is checked, usually that the person has the permission to cross through the barriers.