Editing Mode choice (section)

==History==
[[File:A Short History of Traffic Engineering.jpg|thumb|A Short History of Traffic Engineering]]
The early [[transportation]] planning model developed by the [[Chicago Area Transportation Study]] (CATS) focused on [[Public transport|transit]].  It wanted to know how much travel would continue by transit.  The CATS divided transit trips into two classes:  trips to the [[Central Business District]], or CBD (mainly by subway/elevated transit, express buses, and commuter trains) and other (mainly on the local bus system).  For the latter, increases in auto ownership and use were a trade-off against bus use; trend data were used.  CBD travel was analyzed using historic mode choice data together with projections of CBD land uses.  Somewhat similar techniques were used in many studies.  Two decades after CATS, for example, the London study followed essentially the same procedure, but in this case, researchers first divided trips into those made in the inner part of the city and those in the outer part. This procedure was followed because it was thought that income (resulting in the purchase and use of automobiles) drove mode choice.