No, we have those radar speed-indicator signs out here in the boondocks, too. Problem is that you're only in front of them briefly so it's hard to check back and forth with your speedometer and get a consistent measurement at various speeds.

Anyway around here, they're all K-band whereas the highway patrol uses all KA-band, so it's not much of a radar detector test. Although mine certainly tells me long enough in advance that one of those indicator signs is up ahead...