But it isn't just about the convenience. In our business I cost our travel time to and from a job at $50 per hour. This covers vehicle running costs (fuel, depreciation etc) and wages. So to shave 30 minutes off a job by using a toll road means that I am saving my business $25 in expenses. In this case, using toll roads also makes economic sense because the tolls spent are less than what it would have cost me to go the "free" route.
And now I'm off to repeat the experience.