I made a visualisation of traffic flow, in stations and carriers, for two different types of hangar. A 1-way hangar is an enclosed space with only 1 entrance for a ship. A 2-way hangar is an enclosed space with 1 entrance and 1 exit.
The 1-way hangar requires less space to install in a ship, you can simply paste it onto the side of the ship. A more complex configuration would be the cave-like design we often see in sci-fi ships, where several 1-way hangars are installed in the sides of a larger hangar with 1 or more entrances and exits. This type of setup works fine with little traffic, but may become problematic when there's a lot of ingoing and outgoing ships. Elite: Dangerous spacestations are a good example of a hangar using the same opening as an entrance and as an exit door. You have to wait for eachother or you risk collision.
The 2-way hangar requires the design of traffic corridors. In general it will require less entrance corridors and more exit corridors, as shown in the image below. Each corridor can be filled with ship traffic going in the same direction. You can still collide with eachother, but the relative speed between two ships don't differ as much because their speed vectors point in roughly the same direction.
Both hangar types allow for many interesting configurations. I would like to start a discussion here for what would be interesting configuration, both in terms of traffic flow and in aesthetics. Let me know what you think, and please post your own drawings of interesting designs