4

The entry condition is the same as 3; however, the path of travel flows to the left. An individual passing through this space is required to make a sharp turn to the left to exit.

The main feature that separates this diagram from the previous ones is the fact that the path of travel is forced; that is, it does not exactly follow an individual's natural flow.

Previous assumptions are made regarding the density of pedestrians and the size of the space (although not previously indicated, the spaces are around 15'x15'). The spaces beyond the entrance and exit are also the same as indicated in 3: open and undefined.

If the space were much larger, with the same level of pedestrian traffic, than the flow would not be unnatural as an individual could make a very comfortable turn to the left. Alternately, if the spaces beyond the entry and exit were not open and undefined, but instead were closed and small, than this path of travel would be natural, as the pedestrians would be moving at a slow pace and can thus adjust to changes in trajectory much quicker.

In this diagram, the interruption in natural flow is represented by the circular (turbulence) lines.