If you live along a bus line, THIS does make a difference

I live along the 15 line, at a red light.
The noise from buses starting from a stop can be quite annoying.
The 3000 series buses are really a great improvement as far as noise is concerned.
And the hybrid buses are even quieter!
Too bad they only got 4 of them but the 3000's aint bad!

TriMet: Building a Better Bus (55 New Buses Arrive Fall 2012)