Where was the first study of the four steps in the travel demand model conducted?

• A. New York, 1960
• B. Chicago, 1955
• C. Los Angeles, 1950
• D. Boston, 1970

Answer: (B)

Understanding where the four-step travel-demand model was first studied highlights how planners first formalized a practical forecasting framework. The Chicago Area Transportation Study in 1955 is widely credited as the earliest comprehensive application of the four-step approach—trip generation, trip distribution, mode choice, and route assignment—into a single planning process. This study showed how to use socio-economic data to estimate how many trips originate from each zone, how those trips are distributed across zones, how modes are chosen, and how the resulting trips are routed on the network. That integration demonstrated a repeatable method for forecasting regional travel demand, and it set the pattern that would be adopted and refined in planning practice for years to come. The other locations and dates represent important work in the field but did not inaugurate the formal four-step framework in the same way Chicago did.