The decision referenced by Orin doesn't bother me so much. The measurement in a straight line from the school to the location of a drug dealer makes sense. You are trying to create a dealer-free zone because kids congregate on or near campus and it's a natural place to prey upon them.
When I was in Junior High School (7-9th grade) there was a road that was barricaded off behind both the Junior High and the High School; it went about 100 feet further to the High School parking lot and I'm sure it was blocked off because the local suburbanites complained). It was the quickest way for those of us who walked to get to school and the area around that gate got clogged every morning with kids who hung out there - mostly the kids who viewed themselves as "cool" (though many of us just thought of them as the "dopers") and there was usually a funny odor in the air as I walked through them (I just wanted to get to school). These guys would pull up in a car out on the street and deal pretty brazenly. Then, in the 8th grade I was sitting in my homeroom about 5 minutes before school started and a kid, whom I remember as a big time doper, came dashing in the door. The police had raided the area, coming out of houses at the end of the street and arresting a bunch of kids and catching the guys who were dealing from their car. Doper swore that cops had even come down out of this huge tree which was out there. After that nobody hung out at the end of the street anymore and, I think the psychic shock caused the class years around mine to have less drug penetration then normal (beer & whiskey, on the other hand . . .).
Anyway, the dealers' car was parked on the street. As you walked to the High School, I'm pretty sure it was over 1,000 feet from the buildings, even as a crow flies. However, there was one row of houses between where they parked and the Junior High School. Walking around these houses probably put them over 1,000 feet from the school. As the crow flies, I doubt it was 500 feet. As I think back on it, there is no doubt in my mind that they were preying on the kids as they walked in to school. I've got no problems with the 1,000 foot safety zone.
Next time in the Strange Things in Ken's Life Theatre: Someday I'll have to tell ya'll about the day I was approached and asked to deal.