King County Metro silently fixed a major scheduling mistake for routes 71, 72, and 73 in the February 2011 service change. Those routes together provide frequent service between Downtown Seattle and NE 65th St in Roosevelt via the University District. Buses are supposed to arrive at evenly spaced intervals (headways), about every 7.5-10 minutes during most of the day and at least every 15 minutes from 5 am to midnight. However, the combined schedule for those routes in the past six months had buses arriving at irregular intervals, leading to bunching and long gaps in service. The new schedule restores the even spacing (actually more regular than the Feb 2009 schedule) on weekdays. For some reason, the combined timetable is not available online but the new blue timetables are already out (photo excerpts: weekday 1, weekday 2, Saturday).
For example, people had to wait 18 minutes in the middle of the morning rush hour for a 72 and 73 to arrive simultaneously. If they missed those two, then they had to wait another 12 minutes, then another 5 minutes, and so on. This is a service that’s supposed to always arrive every 7-8 minutes during that period. Another frustrating case was having the last non-owl trip of the night arrive one minute after the trip before it, leaving people waiting an hour for the owl bus. That pair is now 15 minutes apart like the other late night trips.
When you design a high frequency trunk line created from less-frequent branches, it is important to have evenly spaced service to minimize wait time and bunching on the trunk. With this irregular schedule, buses are both bunched on purpose (by schedule) and unintentionally (by delays), leading to a reduction in usable capacity by having overcrowded buses trailed by relatively empty buses. This cannot be called “efficiency”, if that was the original intent. Intentional or not, Metro realized its mistake and fixed it, likely after a bunch of customer and operator complaints.