Determining the distance between two ZIP codes (alternatives to mapdist)

Question

I want to calculate the distance between approx. 100,000 different ZIP codes. I know about the mapdist function in the ggmap package

Answer 1

If you start a new R session and run library(ggmap) in the new session, you can make another 2500 queries.

Function distQueryCheck() shows how many queries are remaining.

Answer 2

taRifx.geo::georoute (only available here until I push out another update, at which point it will be available via install.packages) can use Bing Maps (which supports I believe 25k per day) and can return a distance.

georoute( c("3817 Spruce St, Philadelphia, PA 19104", 
            "9000 Rockville Pike, Bethesda, Maryland 20892"), 
             verbose=TRUE, returntype="time", 
             service="bing" )

You'll have to get a Bing Maps API key and set it in your R global options (ideal placement is in .Rprofile), but the key is free:

options(BingMapsKey="whateverBingGivesYouForYourKey")

Answer 3

This might be trivial, but one completely free option is to use Census ZCTA geography data to get co-ordinates for each zip code, and then calculate Haversine distances (or some similar distance metric) between coordinates.