I have done a fair amount of road trip related projects, including routing baseball trips as well as golf trips . The golf trip tool linked here is a sort of ambitious traveling tool, picking top golf courses and building an efficient road trip for the selected courses.
But what if we looked at this a little differently, maybe not quite so ambitiously ? Suppose we wanted to know all the golf courses within a given driving distance of your home town ? That is, you might be asking where can I go within 3 hours of home ? Well, you might say, I can drive about 200 miles in 3 hours, so let me find all the courses within 200 miles. That is a sort of standard GIS problem (finding all points of interest within a given distance). But I might suggest that if you are planning on drawing a circle with a radius of 200 miles around your home, then you don’t live in Chicago, with its traffic and that big lake sitting there.
But all is not lost; we are looking at a slightly different problem which is fairly well known. Rather than drawing that circle, we will draw a polygon called an isochrone (iso = same, chrone = time) where anything falling within the polygon is within a given driving distance of the center point.
For now, we will show an example of an isochrone , and then later walk through the process of a creating some isochrones that will show golf courses within a given driving time of a point. Here is an isochrone which represents all points within a one hour drive of downtown (note the lack of driving on the actual lake). This was created using QGIS.