Coach's Corner — Are Cycling Radar Lights Worth It?
Our Coach’s Corner series is your chance to have your biggest cycling questions answered — right from longtime cycling coach Darryl MacKenzie. In these short Q&As, Coach Darryl speaks from his 35+ years of cycling and coaching experience to help you become a stronger, smarter cyclist.
Tech-Loving Cyclist:
Coach, I’m thinking about getting a radar tail light like the Garmin Varia RCT715. Are they worth it?
Coach Darryl:
Cyclists are always looking for ways to improve safety on the road. Devices like the Garmin Varia RCT715 combine three features in one unit: a flashing rear light, a camera to record traffic behind you, and radar that warns you when vehicles are approaching from the rear.
Depending on where you ride, this device can be either your best friend — or your most aggravating enemy.
When Radar Works Well
The radar feature works best on two-lane country roads with light traffic, especially roads that don’t have bike lanes.
In those situations, the device warns you whenever a vehicle approaches from behind. That can be extremely helpful. Instead of constantly looking over your shoulder, you know when a car is coming and can adjust your line on the road accordingly.
If most of your riding happens on quiet rural roads like this, a radar tail light can be a very useful tool. Many cyclists who ride in those environments love them.
When Radar Becomes Less Helpful
However, you may find these tools less helpful if your riding terrain changes.
If you ride on bike paths that run alongside busy roads or freeways, the radar may detect vehicles that are nowhere near you. Even if the road is far to the side — 50 feet (15 meters) away or more — the radar can still pick up traffic traveling in the same direction.
I ride frequently on the Silver Strand, a long bike path that runs parallel to a busy freeway in San Diego. There may be six to 15 bike lengths between me and the automobile traffic, yet the radar still warns me every time a car passes on the freeway. On one recent 9-mile ride on the Silver Strand, I had 175 warnings, and only three of them were for bikes in my lane. The rest were false alarms for traffic that was well clear of me.
On long rides in these situations, you can be inundated with constant alerts.
The “Cry Wolf” Problem
When a device sends alerts that aren’t relevant to your riding situation, you eventually start ignoring them. It’s like those push notifications on your phone that you learn to scroll right past.
If more than 90% of the warnings are coming from vehicles that are nowhere near you, you’ll soon tune them out. That’s not ideal, because the point of a warning system is to alert you when there’s actually a threat.
It becomes a bit like the boy who cried wolf. Eventually, the warnings stop offering useful information, even when you need it.
The Takeaway
Technology can improve safety, but it’s important to choose tools that match the type of riding you actually do.
If you ride primarily on quiet roads with occasional traffic behind you, a radar tail light can be extremely useful.
But if most of your riding is on bike paths next to busy highways, the constant alerts may become more distracting than helpful.
The key is to choose equipment that supports awareness and focus — not technology that adds unnecessary noise.
Photo by Mikita Kavaleuski on Pexels
