Honestly, you're overthinking it. Radio traffic updates are just a holdover/tradition from 10 years back and earlier when we didn't all have realtime traffic info in our pocket.
I live in the Chicago area and listen to public radio on my way to work, and the traffic update is just a list of the same half dozen freeways and stating there is a delay of either 20, 30, or 40 minutes between the same reference points. This takes 20 seconds tops, is useful to nobody, and they rattle through it with the same efficiency and flair of a DJ reading a spot for the local car wash. But they have probably been reading the same script at the same time for 40 years like station IDs and other familiar hooks.
Fuck car culture and all, but relax and take a breath... not everything is some weird insidious plot.