How far would kids walk for cannabis?

The Netherlands are famous for their coffeeshops, places where one can buy cannabis for personal consumption without being bothered by the authorities. However, the Dutch government is planning new legislation that will force coffeeshops located within 350 meters of a school to close. Some of my students are reporting about the results of these plans for the coffeeshops in the city of Leiden. A nice opportunity for me to play around with the Google Maps API.

The map below shows all coffeeshops, elementary schools (in red) and high schools (blue) in Leiden. By hovering over the schools you can see which coffeeshops are within the 350 meters zone and would have to close. You can also have all perimeters revealed at once to see that just one of the 11 existing coffeeshops will survive when the rule will be applied to both elementary as high schools, whereas just one none of them has to close down if the rule will only affect high schools. It’s not yet clear how the new law will calculate the 350 meters but in this mashup they are measured in a straight line, not as the actual walking distance from the school to the coffeeshop.

Of course the map doesn’t answer all kinds of interesting questions. Like how far school kids would walk to get their cannabis. Or where they are going to buy their drugs when the coffeeshops are all closed. Nevertheless it would be very interesting to create a similar map for Amsterdam (over 200 coffeeshops) or the entire country. If you have suggestions for improving this interactive, feel free to share them in the comments!