For a long drive, calculate "% of time spent in traffic" and "# of minutes spent in traffic" and include that as a criteria.

We just stared at 3 different routes for a 4+ hour drive that had varying lengths and amount of time in stop & go traffic. We would have liked to have selected easily "the one that makes the car move the most and has the least stop & go, so we don't get car sick and our children don't wake up."