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.