Mike:
My last sale was of the house I am currently using as my avitar and it was on a busier road. The road was a definate factor in alot of people's decisions. The home sat on 2 acres and was approximately 150 from a busier road. It did not matter that it had great views looking at a ski resort, sat on over 2 acres, had it's own private stream, backed up to woods and was well shielded from the road via mature trees becuase the majority all said " It's a beautiful house, but it's too close to the road".
I always try to find out what potential buyers think, especially if they have no further interest. In this area I was very friendly with the local realtors and knew most of them, so I was able to get good feedback. All would report back "It's too close to the road!" Unfortunately, this was one thing I couldn't easily change.
This particular home was in in a second home area and in most communities 150 feet from the road would be very desirable, but it wasn;t in my case and the reality is that a busy road will kill alot of interest.
Homes in this area were taking 5 to 9 months to sell. Mine finally sold in 18.The lesson I learned is" Location,location,location. I would think twice before buying on a busy road.