Bob R. I'd love to see the full communication behind that statistic ... but taking your numbers at face value, they are in the ballpark of automobiles. TriMet reports an average number of 32 bus boarding rides per vehicle hour (142 for rail). Assuming a bus operates at least 12 hours per day on average, that's 140,000 boardings per year. (That's an assumption -- if anyone knows the average number of vehicle hours per bus, please let us know.) How many automobiles serve 140,000 boardings per year, or anywhere near that ballpark?
JK: There you go again, picking arguments out of thin air.

The statement was “each TriMet bus chews up the roads equal to 22,000 cars”

The average Trimut bus carries 9 people. The average car carries 1.2 (your number).

Translating to people: cars: 22,000 x 1.2 = 26,4000
Buses: 9
Based on passengers, the bus does 2933 ( 26,400 / 9) times a much damage as cars. Just another reason that transit users should pay more.

Drive a small car, save money, energy and the road.

Stop Sam’s Tax: No Billions for Bikes, buses and bubble curbs

Thanks
JK