I drive two states in a car for my business and several other states on a motorcycle for fun. I've found that "radar detectors" are of very limited usefulness now because of the widespread use of "instant -on" radar and lasers. There is very little beam scatter for your "radar detector" to pick up and warn you.
One of the best defenses is an app like WAZE with real-time traffic, hazards, detours, gas prices, and (stationary) police. WAZE is free, too, and only uses minimal "data". I use it running on an old cellphone (hotspotted to my active cell phone) and mounted on the dash beside my Garmin in my car and on my bike. The main deficiency is that WAZE has no way to warn of moving/traveling police. The best defense for that would be a CB radio but I don't use one.
A couple of free suggestions that might help you are to stay out of the right-hand lane as much as possible; don't be the fastest one out there; travel 1/4 mile behind another vehicle going your way at your preferred speed; but most of all, BE OBSERVANT, i.e. watch the other drivers. If the truckers are all slowing down take the hint; if people on your side of the road are slowing and bunching up take the hint; oncoming flashing headlights are a strong hint as well.
It may sound strange but I've found that being very courteous, especially to big trucks, pays dividends in this department as well as just making you feel better, too.
Good luck out there. Stay safe.