filter traffic noise

I finally managed to persuade my grandfather to tell me about his wartime
experiences while I recorded him onto my Palm T3. It is very emotional for
him and sometimes he was almost whispering. Now when I listen to the
recording, all I hear is traffic noise (and then for a few minutes the
washing machine) but I didn't even notice these at the time. I don't think
he would accept to be interviewed again. Is there anyway I can filter these
sounds out relatively simply. I have some software called AudioEdit but I
can't figure out how to use it.

Any pointers would me really appreciated.

Many thanks in advance

Rick