K40 RLS2 Radar Detector Review

The Daily Grind

Subaru BRZ on forest road
Photo credit: Picky Wallpapers

My daily commute consists of about an hour’s drive on highways, quiet back roads, and the congested city, so it’s an excellent test for the RLS2. Filtration and false alerts are so much better than the old detectors I used in the past. The only false alerts I received are still genuine speed radar – in this case, radar signs that measure and display your speed. One of these is permanently installed in a school zone, so I used the Mark to Mute function. The RLS2 automatically connects to GPS data, which is how it knows where you are, how fast you’re going, and what direction you’re heading. Mark to Mute tells it to automatically mute audio alerts for the currently active band within 1500 feet of your current location. From that point on, the visual alert will still display, but the RLS2 will remain silent.

The other false signal was another radar sign, this one a portable unit. At first I didn’t Mark to Mute it, since I’ve seen actual speedtraps in the same area. One day, much to my surprise, after passing this sign I received simultaneous alerts for K-Band and Ka-Band. At first I didn’t understand why, but then I saw a police car approaching from the other direction! The RLS2 had given me alerts for both radar sources – K-Band for the sign, and Ka-Band for the actual cruiser. This also taught me that this town’s police use Ka-Band rather than K-Band. This meant that I could safely Mark to Mute the portable radar sign on K-Band. An actual speedtrap, even one hiding in the shadow of the sign’s false K-Band alert, wouldn’t be hidden from the RLS2, as Ka-Band alerts are still active. The following week, the portable radar sign went away. I removed the Mark to Mute feature from that location by simply pressing the button again as I passed by. Now I’ll get any new alerts in the area.

A tough test for the RLS2’s filters is Speen Street in Natick, MA. There are many businesses and strip malls there, including the popular Natick Mall. It’s an area infested with numerous false radar sources. Yet the RLS2 doesn’t give me a single false alert there. Impressive. Most impressive.

Speed trap
Photo credit: Kansas City Star

On a back road one morning, an oncoming Mercedes flashed his lights at me wildly. I was approaching an area where I’ve seen a speedtrap many times before. Soon afterward, Waze alerted me to police in half a mile. Before I rounded the corner, the RLS2 gave me a K-Band alert, and sure enough the speedtrap was active as I came into view going slightly below the limit. Any one of these warnings alone would’ve been enough for me to make sure I was going the limit. In fact, I see this particular speedtrap so often that I always make sure I’m at or below the limit anytime I pass through. But confirmation is always good. There was enough time between Waze, the Mercedes, and actually entering the speedtrap myself that the cop could’ve moved or chased down a perp. The RLS2 confirmed that this trap was active, right now, setting its sights on me. It also confirmed that this particular town still uses K-Band, so I should pay attention to those alerts as well as Ka-Band.

Just how sensitive is the RLS2? One time Waze alerted me to a speedtrap on the other side of the road, so I made sure I was going the speed limit. It was a clever location, and completely hidden behind a row of trees until I was already passing the trap. The officer was aiming down the road in the direction I was going, not in the direction I had come from. However, the RLS2 still picked up his radar long enough before I passed him that even if I’d been speeding at the time, I wouldn’t have been by the time he saw me.

It’s worth pointing out that although I could see this particular speedtrap on my map, Waze did NOT alert me to it because it was on the other side of the road. That shouldn’t matter, and if I’d blown by at 50 in a 30 zone, he would’ve rightfully nailed me. On another day I had four Ka-Band contacts on my way to the office. I spotted three of them with my own eyes, one of whom was in motion – something Waze can’t tell you. The fourth was probably a state trooper going the opposite direction on the highway, since the radar contact came and went rather quickly. Waze is good, but it has limitations.