Number 12: Does radar REALLY keep us safer?

You got a rear bike radar for Xmas. You love it. Now the group rides sound like an electronic polka party every time a car comes near us. Are we safer?

No surprise, there’s really no research yet establishing that riders with radar have fewer collisions with cars. A quick search only yielded one review article (Jannah et al., 2025) and it pretty much summed up what you and I know from experience. Studies have found that “most participating cyclists responded positively to the warning technologies/systems… warning technologies/systems influenced some cyclists’ behaviour during critical situations, such as early braking, faster reactions, increased focus, maintaining a safer distance, and temporarily reducing speed…(but) only two studies tried to explore how warning systems affect crash risk.”

So, riders like their radar, and the alerts do change rider behaviour, but we don’t really know if the radar is saving lives or reducing accidents.

I’m a curmudgeon as you know, and I resist buying a radar on the basis that I can hear the cars coming (although EVs are pretty quiet) and I keep well to the right (at least, when I’m not in a group) so I don’t see the benefit. Also, when I’m in a group, everybody else has one so why spend the $300? But that’s not the question on the floor. The question is, on a group ride, are these things keeping us safer? 

Here’s a “no” argument from experience. I’ve been on a few Amici rides where the wind is from the left, the leader is in the middle of the lane (so far, so good) and when their radar beeps the leader swings to the right. That’s not good or safe. To be fair, that’s my only negative. Most of the time all the beeps go off, and everyone continues SPACE-ily (remember Smooth, Proficient, Aware, Communicating and Encouraging?). Maybe with the beeps they are more A, but as long as they stay S, I’m OK with it. So if you are reacting to the beep by tightening up and swerving right, please stop. Maybe the thing is causing you anxiety. Otherwise, please carry on. 

Here’s a different case where the things could help, but I’ve yet to see it. Often when we have a left turn across traffic coming up, somebody calls “take the road” about 150 m from the intersection. I guess the theory is if we are all in the middle of the lane, a car coming up from behind at 100 kph will slow down placidly and wait patiently behind us until we turn. If you look for me, you’ll notice I usually wait until about 50 m from the turn to move left. I just don’t happen to think we should obstruct the lane sooner than we need to. Could radar help? Could we get a bit closer to the turn before “taking the road” if there is no “beep”? 

Anyway, I’m glad you love your radar and if you feel safer, I’m doubly glad. I’ll probably buy one soon. Maybe.