Date Added: Mar 2010
SAS 9.2 contains new functions (ZIPCITYDISTANCE, GEODIST) that allow a user to compute geodesic distance (the shortest distance between two points on the surface of a sphere). Both functions use the Vincenty distance formula. Prior to SAS 9.2, a data step was used to compute such distances, commonly with the Haversine formula. Vincenty and Haversine distance estimates are straight line distances and there are occasions where that type of estimate is what one needs. There are other occasions where what one wants is not the straight line distance, but a driving distance. Given only one combination of locations, using Google Maps to get the driving distance and time is no problem.