There can be several ways to handle traffic flows separately. A distinction can be made between vehicle types (person cars and trucks), between people how are willing to pay (HOT lane) or it can be the destination (short distance vs. long distance). In the Netherlands around cities sometimes a distinction is made between short and long distance traffic, which are separated by different carriageways. The question is when this separation is useful and when not.
September 1, 2016
Separating traffic flows: when and how?