Nice to see the localhost solution! I (my team) did very similar when I was a postdoc. In 2015 we used the HERE API (www.here.com) to map geographical access to hospitals in the entirety of two countries, USA and Brazil.
As starting point, I used the lat/lon of the population center of each census block group as provided by Census.gov. In Brazil the closest geographical equivalent is the setor censitário (census sector). I used Haversine distance (great circle distance between lat/lon's) to narrow the search space to the 5 closest hospitals, from the hospital database by the American Hospital Association, and the Brazilian CNES registry (Cadastro Nacional de Estabelecimentos de Saúde). From those 5 closest candidates, I then asked the HERE API for the true driving time to their address. Many many API calls.
We plotted average driving time against variables from the census block group provided by the American Community Survey to show how values change as driving distances change. Mostly just to demonstrate the kind of analyses possible. I presented the work at the NLM Informatics Training confereces, e.g. with many pictures of maps: https://github.com/fabkury/drithop/raw/master/Kury%20-%20dri... . Source code (but not data) are in the GitHub repo `drithop`. The maps are self-contained HTML files and interactive using OpenStreetMap.
As starting point, I used the lat/lon of the population center of each census block group as provided by Census.gov. In Brazil the closest geographical equivalent is the setor censitário (census sector). I used Haversine distance (great circle distance between lat/lon's) to narrow the search space to the 5 closest hospitals, from the hospital database by the American Hospital Association, and the Brazilian CNES registry (Cadastro Nacional de Estabelecimentos de Saúde). From those 5 closest candidates, I then asked the HERE API for the true driving time to their address. Many many API calls.
We plotted average driving time against variables from the census block group provided by the American Community Survey to show how values change as driving distances change. Mostly just to demonstrate the kind of analyses possible. I presented the work at the NLM Informatics Training confereces, e.g. with many pictures of maps: https://github.com/fabkury/drithop/raw/master/Kury%20-%20dri... . Source code (but not data) are in the GitHub repo `drithop`. The maps are self-contained HTML files and interactive using OpenStreetMap.