Which of the following is NOT a step in the standard four-step transportation planning method?

• A. Trip Generation
• B. Trip Distribution
• C. Network Design
• D. Trip Assignment

Answer: (C)

The standard four-step transportation planning method works by forecasting travel demand through four linked stages: estimating how many trips are generated, distributing those trips to destinations, selecting modes of travel, and then assigning the trips to the road network to see where and how congested routes would be. Network design, while important in planning, focuses on the layout, capacity, and geometry of the transportation system itself rather than forecasting travel demand. It’s a planning/design activity that comes before or after forecasting, not a step in the demand-forecasting sequence. So the item that isn’t part of the four-step method is network design.