I'm looking for a device that is able to calculate distance traveled along a mapped route.?

There is a chain called lattitudes. They have one in Atlanta. Try them. Also a store called The Map store in Washington, DC.

I think the others answered for this particular device. I invested in a program for my laptop that is from the mapping company DeLorme in Maine. The program comes with an online map of the USA and Canada. You can put in the start point and end point and ask for the milage. That will be immediately displayed. On an important trip or one the involves making judgements about the route to take, I spend more time in prep. before trip. The program is not for the weak. I find it has a long learning curve and not always friendly user interface. Also, you can buy it with a USB GPS locator device for use in the car. I plug my computer into the car's power port, the GPS device into my computer and make sure the volum is up on the PC. You can also plug in headsets and microphone as you can ask questions and give commands as you go along. I can only remember a few questions so it isn't too much help, but can be good for saying Next Turn? After writing all this, I recommend using the above only if you are fascinated with computer use and mapping routes. Otherwise I would stick with the device you are looking for. Whew! Oh, join the AAA and ask them to map the route for you and tell you how long it is. They might sell that device, as well.