Drawing multiple routes on a roadmap
The R package Leaflet can be used to draw beautiful maps. Polygon shapes can be added to draw lines and borders. By combining these functionalities with GPS data, you can easily draw roadmaps of your recent whereabouts (or tag your cat with a GPS tracker and see where he likes to hang out over the weekends). Besides detailed GPS data of your route, you can also use simple start-destination combinations and let a route planner API come up with the exact GPS coordinates of the route. A taxi company for example, can draw maps of its customer exposure to the city or track hotspots that are often visited by drivers. A delivery service can identify regions where they have little presence and where they perhaps should invest in customer awareness.
In R, a list of 1000 cities was formed by selecting postal codes with replacement by distance from a random subset of Western European cities. All starting points where set to be in Venlo or Rotterdam, the Netherlands. Using ggmap, cities were translated into GPS coordinates and routes were calculated. These routes were then plotted on a CartoDB map using the Leaflet package.
These maps can be produced quite fast, and they are easily integrated into interactive applications by using the Shiny package. They could be used to study traffic flow or for marketing purposes.