You’re so right. The “traffic study” has to be the most ridiculous game of all. Someone paid by the developers who want the study to show no change to traffic patterns from an 18 story condo/office/shopping tower plunked in the middle of a congested suburban shopping miraculously produces a study showing that the additional 500 cars a day will produce no change in traffic patterns. Every time.
The opposite scenario is true also, of course.
When governments want to raise gas or property taxes to build roads they suddenly discover and announce that roads we already knew were oversubscribed need to be expanded and announce scary volume statistics.
One hates to be a cynic but it’s the only way to keep one’s sanity.