They did say per driver. It's still a high number of course, but I don't see how you can read that differently? UPS has around 400,000 employees, so if 200,000 of those are drivers that number becomes $150 per mile saved. Still way too high, but not single use golden robots high.
I think the goal has to be to read what it doesn't say.
The most sensible interpretation I can come up with is saving 1 route mile for each driver for a year (that is, chopping 365 miles off the work of one driver). That puts the per mile savings right around $0.40.
