Consider that we already have vehicles (in prototype) that can outperform a human behind the wheel. Hell, Stanford is sending an Audi TT up Pike's Peak at 100+ mph (http://bit.ly/9akGU1).
And consider that truck drivers are basically meat-based robots anyway inasmuch as they are all practically interchangeable.
Once the first trucking company gets the idea to start replacing drivers, that's going to put them at such an insane competitive advantage that the rest of the industry will have no choice but to follow suit. No downtime, no accidents, far cheaper, no irresponsible behavior.
Once the process is started, the entire delivery driver industry is going to be obsoleted within 12 years.
That will be the first time a massive number of people perk up their eyebrows and start wondering if their job is far behind...