Rear-view radar reviewed

Garmin is a high-end manufacturer of GPS devices for bicycles and motor vehicles.

Garmin has posted an ad for a cycling “radar” (probably actually LEDdar using pulsed infrared light), which warns cyclists of overtaking traffic. There are some serious problems with the product concept and with the ad, so once you’ve viewed the ad, please read on.

The $200 Garmin device, an accessory for a bicycle GPS unit which costs several hundreds of dollars, informs the cyclist that a vehicle is about to overtake. But in order to decide what to do about that, the cyclist needs to know how much clearance the vehicle will give. The Garmin device doesn’t provide that information.

The stilted British voice in the ad conveys an air of authority, I suppose, but how is the cyclist in the ad not going to HEAR the huge truck approaching from behind? Unless the cyclist is listening to something at top volume on headphones — but I didn’t see any. The cyclist never once is shown looking back, and he isn’t using a mirror, and so what is the device supposed to let him know that he wouldn’t know anyway? Granted, the device could give a warning of a quiet car.

The “cyclist’s eye view” clip in the video shows his response to the warning: pulling over to the right edge of the roadway, so far that grass would be brushing his right foot and he risks a fall on the cracked pavement — which could turn a brush-by into a fatal.

Imagine what a nuisance this device would be when being passed by strings of vehicles. It would give a continuous warning, which would provide no useful information. One more good reason to use my $15 rear-view mirror to check on overtaking traffic, and use my cell phone for GPS (no extra cost) and forget Garmin!

The ad repeats the figure from a League of American Bicyclist survey of fatal bicycle crashes, that 40% are in overtaking crashes. That widely publicized number has several problems though:

  • First of all,  there are more problems with the numbers. My friend Patricia Kovacs comments:

    LAB’s Every Bicyclist Counts study found 40% of bike fatalities were hit from behind. I’ve been studying crash data in Ohio and in 2015, 30% of bike fatalities were hit from behind. But not all hit from behind are the motorist’s fault. In Ohio, 15 out of 24 fatal bike crashes were the fault of the cyclist, 6 were the fault of the motorist and 3 were no error, according to the police officers’ reports. What were the circumstances for the cyclists at fault? Improper crossing, not visible, failure to yield, lying or illegally in roadway. Most of these circumstances can be mitigated with education. I do worry about drunk and distracted drivers though, which is why I use a mirror.

  • The LAB study is biased in covering only fatal collisions, which are rare. Just as an example, in the over 100 million miles of travel in the 50-year history of the bicycle club to which I belong, approximately 1000 lifetimes of riding for an avid cyclist, there have been only two fatalities to club members. One was a rear-ender and the other was a head-on collision with an out-of-control vehicle that crossed to the wrong side of the road. Non-fatal crashes are hundreds of times as common and result in far more loss of years of useful life. 3/4 of serious bicycle crashes don’t involve a motor vehicle at all.
  • The League puts forward the 40% figure to promote its support for barrier-separated bikeways in urban areas, but fatal overtaking crashes occur mostly on rural roads. Most urban fatalities result from crossing and turning movements.

Half-truths have been used repeatedly to sell cycling infrastructure (as with the League’s study) but Garmin’s is the most sophisticated use of half-truths I’ve seen so far to sell a cycling product, while also being seriously ill-informed.

About jsallen

John S. Allen is the author or co-author of numerous publications about bicycling including Bicycling Street Smarts, which has been adopted as the bicycle driver's manual in several US states. He has been active with the Massachusetts Bicycle Coalition since 1978 and served as a member of the board of Directors of the League of American Bicyclists from 2003 through 2009.
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9 Responses to Rear-view radar reviewed

  1. khal spencer says:

    Thanks a bunch, John. I saw that device as a print ad in Bicycling Magazine and my first thought, as a cyclist who commutes on busy roads, was as you say, “…what a nuisance this device would be when being passed by strings of vehicles.” I had also thought of writing Garmin or Bicycling to ask if the device provided lateral as well as distance information, but frankly, never got around to it. Without information as to whether a motorist was moving to my left, this device would be about as useful as a nervous breakdown, far less useful than a mirror costing a few percent of the Garmin cost, and unable to take the place of situational awareness.

    Good points all around. Again, thank you.

  2. Patricia Kovacs says:

    Thanks for writing this article, John. I wanted to follow up on my data with a little more explanation. I am trying to determine “manner of collision” (angle, rear-end, sideswipe, etc) from crash reports using things like direction of travel and pre-crash action (straight ahead, turning), because bike crashes do not include this important piece of information. With the help of other bicycle educators, we are submitting a request to the national organization which defines crash reports to improve the reporting of bike crashes and I am working with Ohio to do the same here. But in the meantime, my algorithms have found that 10% of ALL bike crashes are rear-end, 5.3% are motorist fault, 3.2% are cyclist fault and 1.5% are “no error”. These at-fault determinations are the decision of the reporting police officer. How could there be “no error” in a traffic crash? Good question and this is what I spend a good deal of time trying to figure out. Regarding the Ohio bike fatalities mentioned in your article, was the cyclist really to blame in 15 of 24 crashes? Well, the cyclist was unable to speak for him/herself, so we hope that the motorist or witness was honest and unbiased.

    • jsallen says:

      “No error” may in fact reflect reporting error, bias or lack of evidence. In some crashes, however, no operator is at fault: particularly, crashes resulting from mechanical failure, malfunctioning traffic signals, rock slides and the like. Thanks, Patricia, for looking closely into the crash reports. A close look sometimes reveals a different story.

  3. Jon Niehof says:

    Ray Maker has pretty comprehensive reviews of the original and the post-buyout Garmin version. It is actually radar (probably 2.4GHz “kitchen sink” band). It’s promising, but I agree get the mirror first (cheaper and more versatile) and I haven’t sprung. There definitely seem to be corner cases where it could be useful. I’m not nearly as thrilled about the blinking at the motorist aspect, and it would be a lot better if a horizontal clearance estimate could be added.

    • Khal Spencer says:

      Someone needs to do the math as to how much time one would have to react if the device actually measured X-Y distance (where Y is lateral distance) as well as closing distance, and gave the cyclist a visual or auditory warning if the motorist was not overtaking safely, i.e., moving laterally relative to the cyclist. Would a cyclist have enough time to react? If so, at what closing speeds? A motorist travelling at 40 mph is overtaking a 20 mph cyclist at about 30 feet per second. I’ve never paid much attention to how far back motorists typically start moving left to overtake me. Hmmm.

  4. Bruce Epperson says:

    Also, the Garmin buzz-box doesn’t help with the most useful task performed by a glasses- or helmet-mount mirror: setting up for a left turn, especially on a multi-lane (4+ lanes) street. When you are up in your fifties, you would not believe how far you have to crane your neck around to look over your shoulder as your cone of vision narrows with age. I would never do a right-left shift without an over-the shoulder looksee (too many blind spots in those little dental mirrors), but man, it’s helpful to be able to juggle scanning the road ahead and the traffic behind without swivel-swivel-swivel.

    I guess if you were really dedicated to the idea of spending $200 where $15 will suffice, how about a helmet-mount rear-view camera that would transmit to your GPS screen on the handlebars. If you can learn to scan with a glasses-mount mirror, you could probably learn to scan with a rear-view camera.

    • jsallen says:

      Good point — though at least in my case, the factors affecting my ability to look back are different. I can’t turn my eyes to more than about 50 degrees to either side to use sharp foveal vision. (I don’t think that it is usual to — I don’t remember ever being able to. I don’t think that there’s eye-yoga to increase this flexibility!) At age 70, I still have peripheral vision to 90 degrees either side when looking straight ahead, perhaps another 10 degrees with my eyes turned to the side — but also, 50 degrees either side of straight ahead is as far as my eyeglasses cover, and so the peripheral vision outside that range is additionally blurred. Then there’s neck stiffness. I rely on my helmet-mounted mirror to look directly back, though, to be sure, I also look over my shoulder in case another bicyclist or motorist I haven’t already noticed is coming up next to me.

  5. yan says:

    Amazing video but a little much on the fear aspect. Otherwise, varia is great product. I would love to test it out .

  6. Mike Lasche says:

    Dear all,

    I would like to see a similar device, but smarter. What if the device tracked the projected path of the overtaking vehicle and only gave a warning if it wasn’t passing safely. Thus, the cyclist would not be bothered if the overtaking vehicle was moving adequately to the left.

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