Don't protect kids. In Massachusetts, for example, seven out of ten drug-free zone incidents occurred while school was not in session, and less than one percent involved sales to youth.
Don't have a deterrent effect. Because the areas overlap and blanket most cities, they are impossible for drug sellers to avoid and thus create no incentive to move drug transactions away from schools.
Have a racist impact. Zones often completely cover many densely populated urban neighborhoods, where people of color are more likely to live. For example, in New Jersey, drug-free zone laws cover three quarters of Newark, in contrast to six percent of rural Mansfield Township.