>Hi, Jim, and thanks for the reply.
>
>>How are they shipping, by commercial carrier or some other means? If commercial
>>carrier, you should be able to get zone definitions and rates from them that will
>>tie into zip codes.
>
>Commercial trucking companies, with various rates depending on the
>type of truck used. Currently, the guys in the shipping deparment
>are going on-line and looking up the driving distance on google maps
>(or some other site..Shrug), and then they're inserting that value
>into the local VFP database associated with the app. So, the app
>looks to see if the distance already exists, and if it does, then
>it displays the value on screen. If not, then the end user has to
>go to the web and get the value.

You may try to calculate the ratio between the geometric (or rather, geodesic) distance with the actual road distance for those routes you already have, and see how does that ratio distribute geographically. I assume it'd be lower for flatlands and worse for mountains, but without comparing the actual data can't know how much.

You may come up with a better guesstimate for the next time. Actually the system would learn as it goes.