They used to have a section on here that would tell you, but it was closed last time I checked. The sales department at cavalier (or any DSL/Telco ISP) should be able to access that information as well and let you know.
You could also go to where's my C.O. section
(for instance my NPA NXX is 216-531. Scrolling down we see the C.O. is physically located at 18900 NOTTINGHAM RD. If I google map/direction it, I get 2 miles X 5280 ft = 10560 ft. Now I've been told by AT&T that there are screwy wire runs here and my distance may be as much as 12,000 ft but of course the linesman who told me that is in fact an azz so I don't know if I believe him. At any rate, my great distance from my C.O. is why I switched to cable because even with DSL2 my speeds topped out at 4.2 mbps tops and 3.5 avg.
I'm now getting about 13 mbps down and 700 kbps up with RR turbo.