(Not trying the article's domain against the corporate firewall, sorry) Sometimes it's because there's traffic going the opposite way. Many buses travel a circ

(Not trying the article's domain against the corporate firewall, sorry) Sometimes it's because there's traffic going the opposite way. Many buses travel a circuit, so their route ends at its beginning. If your bus is late, maybe it was stuck in traffic an hour ago, and was late to every stop since that traffic. Traffic itself becomes a travel-time multiplier - driving a car home from some offices, leaving at 3pm would get me home at 3:30. But leaving at 3:15 gets me home at 4. Leaving at 3:30 gets me home at 4:30. It seems to describe a bell curve that maximizes about 5:30 or 6pm.