Is there a reason the 40 is always so late? More than the 8?

I’ve been living in Seattle for 7 years and the bus that gives me the most headache is the 40 line. It is chronically late. I feel that it is more frequently late than the 8 bus, and for longer stretches. It even starts late from its first stop at Northgate station. At night it is wholly unreliable. It is one of the buses I rely on the most based on where I live, and frustrates me to no end. It is consistently very late after 8:00 p.m. Why is this?

I write this as I am waiting on a 30-minute+ delay 40 bus in Ballard at 9:00 p.m. I’m so frustrated that most of the other buses seem to operate within normal timetables, not being late more than 10-20 minutes. Two 44 busses have come and gone as I wait here. But the 40 is consistently late and by very large stretches of time. I’ve submitted multiple complaints to King County Metro over the years and nothing ever gets done.

I just don’t understand why this bus in particular struggles so much at night. Especially when there aren’t a lot of cars on the road. I will see empty 40 busses sitting in the Northgate station bus bays, driverless, accruing longer and longer delays. Is it an unpopular route to staff? I just can’t figure out why this bus in particular seems to be so miserable. Does anyone know?