This is a highly subjective topic. Since no two houses are alike you can’t just take on a busy street and one not and say there’s the “cost” of living on a busy street. The Oregonian ran an article a couple of weeks back. One of the key points being that buying a house on busy street might allow you to enter a neighborhood you could not afford otherwise.
I chose a couple of streets: one busy and another a couple of blocks off that street. The difference between SE 39th and SE 41st is just what I expected; $26/SQFT (all listings single family detached and sold in the last 12 months).
Between Burnside and the 4000 block of SE 39th and 41st:
39th $140/SQFT (8 sold)
41st $166/SQFT (8 sold)
That equates to a $52,000 difference on a 2000SQFT house.
NE Fremont and NE Klickitat between 30th-50th:
Fremont $206/SQFT (2 sold)
Klickitat $210/SQFT (4 sold)
Much closer but twice the number (though still low) sold on Klickitat. I’m not sure that comparing two and four sales over a one year period is statisticly valid. Other factors that contribute to the difference is the client that never gets out of the car when they realize it is a busy street. Also interesting is that the time on market was 10 days for the two Fremont houses and 62 for the Klickitat houses. So much for proving a point with these stats.