Sharraxaadda

I currently live on Waterville st. and have noticed semi-trucks pulling in to Birch St. very fast, well over the speed limit. Waterville St. is already a fairly narrow st and the trucks always take the corner very wide and have almost hit oncoming traffic several times. I also did some research and noticed the plot is zoned as residential. Why is a trucking company allowed to operate out of a residential neighborhood so close to an elementary school?