Cars ghosting (false all-clear) a lot

It seems like it's getting worse, but probably just me noticing it more. The RCT715 is "losing" an awful lot of cars. Two things cause this to happen; thing one is when a car comes up from behind and then "paces" me for a while. The RCT715 apparently thinks it's a bike riding with me. It's very disconcerting that you get a green lane with the all-clear beep when this happens. And in the city, it happens a lot.

The other occurs on windy roads, where it picks up the car from quite a distance away (obviously when there's line of sight visibility) but loses them (and goes to all-clear) way too quickly. The garmin can tell when you're on a windy stretch of road; the software should allow for a longer period of time before giving the all-clear on such windy stretches

  • But that was also the case with 515/516 (and probably others too), that if a car has to slow down behind you because of traffic, it then “disappears” and then suddenly reappears behind you when it accelerates. Or am I wrong here?

  • Yes, in my experience that has always been the case with all 3 different Varia radars I've owned. I've not noticed it be any better or worse on the RCT715. At the end of the day, the radar/software isn't particularly smart, it just indicates when there's something closing on it. It doesn't seem to use any history or context; once something matches your speed or backs off, it's no longer reported. IIRC, when it was launched, the original Varia didn't even give a green 'all clear' for this very reason, they only introduced the green status later.

    Garmin certainly have the in-house expertise (in their Marine division) to do clever stuff with radar, but I'd imagine if you started doing any in-unit AI processing you'd need to upgrade the processing power, which would have a hit on battery life (and possibly break the ANT protocol). You could do head-end processing on an Edge for example, but I'd guess the inclination isn't there to do that, especially across different dev teams.

  • 500 did this as well.  715 doesn't seem to be any worse than the 500 was from my experience.  I have always treated the radar as a supplemental tool to let me know when a car or other vehicle is approaching.  It's not a replacement for turning your head and checking 6 every now and then and whenever changing your line (not just your lane) to verify you're clear.