I am working on an iOS application which uses GTFS data. The data is provided by the local transit authority. When plotting the route overlays onto a map, I have found a number of outlying data points as seen in the image below:
*Sorry I didn't have enough reputation to post an image
In order to make the data more managable I have filtered the shape data through the Ramer-Douglas-Peucker Algorithm to remove redundant data points.
I am unsure of how to process the data further to remove these obviously incorrect points. Could someone offer some advice on to filter out these data points?