Public transport probability

This program uses OpenStreetMap data to calculate the chance of a hashpoint lying within X kilometres of a train station or bus stop.

Usage

First, get the OpenStreetMap extract for your graticule (replace 52,13 below with your own graticule).

$ wget 'http://www.informationfreeway.org/api/0.6/node[bbox=13,52,14,53][railway=station|stop|halt|tram_stop]'
$ wget 'http://www.informationfreeway.org/api/0.6/node[bbox=13,52,14,53][highway=bus_stop]'

The first command retrieves all stations and on-request halts. Usually it includes surface rail, underground services and trams. The second retrieves all bus stops.

Next, create a PHP file with the code below, editing the first few lines as appropriate. Run it to create an image file and to output the probabilities. For the first run, I suggest making the $distance very small so you can check whether the OSM data looks complete.

NB: Untested on negative graticules, let me know if you have problems!

Example

For the Berlin, Germany (52,13) graticule:

david@netman1:~/geohashing/berlin$ php process.php
Graticule size: E-W: 67.6534534537 km, N-S: 111.13296 km
Image resolution: 608, 1000
5km ellipse is: 89.8697655422, 89.9823058794
Total pixels: 608000
Train pixels: 417707
Bus pixels: 79080
Chance of train within 5km: 68.70%
Chance of train or bus within 5km; 81.71%