Is he barking hysterically or barking like...."Hey man...What's up ...SEE ME ? I'm on my WALK !!" ...sometimes they're just so excited they have to yell at everyone that goes by...
it he wants to rip everyones shoes off.... you may want to try training classes....if it's just being mouthy - well...training classes for that too
...or.... just kneel down and tell him quietly ...'No bark' ... and sometimes after a while they just learn not to -
I had to do that with Chanel in my old neighborhood...it's too bad we don't walk anymore - I miss it...there's too many big dogs where I live now...