About the laser bike lane…

Lasers projecting the image of a bike lane from a bicycle onto the street (http://www.lightlanebike.com/)? Laser — high tech — must be a great idea then? Not really.

Light shining directly from the vehicle toward the viewer is many times more efficient than lighting the road to indicate the position of the vehicle.

A bike lane that moves with the bicycle conflicts with the road markings on the road.

The page: http://www.lightlanebike.com/about.html (with the red lines) is a Photoshop job. The beam from the light would have to pass through the rider to illuminate everywhere shown, and there is no pavement texture visible in the lines on the pavement.

The green lines at either side on the page http://www.lightlanebike.com/index.html appear to have been generated by a device on the bicycle, but the bicyclist symbol in the middle of the lane looks like a Photoshop job.

The video embedded above and at http://www.lightlanebike.com/prototpye_video.html, [missing from the Web page as of July, 2011] appears indeed to show lines on the roadway projected from a device on the bicycle’s seat post, but not from the device shown on http://www.lightlanebike.com/design.html, as the green spots which the light comes from are too far from the centerline of the bicycle. Also, I just gotta love this masterwork of obfuscation:

“Preliminary contextual research shows its performance in real world situations is best when lighting conditions are at their worst, improving safety in the most critical situations.”

That is to say that light output is weak.

Lasers are hugely inefficient, but because they produce a pencil-thin beam, can send all of it into the pupil of an eye and cause retinal burns if bright enough to light the road — especially, green lasers, whose light is absorbed by the red chorion tissue behind the retina. One reflection from a puddle into the pupil of your eye, of a laser above 10 milliwatts in output power, for as little as a few microseconds — boom — retinal burn, if a mechanical scanning device is used to generate a pattern, as is usual, or if the device stops. A hologram might also be used, but it would reduce efficiency. The lines shown do not extend forward of the bicyclist where most conflicts occur. Notice in the picture that the reflective spots on the cyclist’s shoes show brighter than the taillight included in the laser device, when the cyclist is in the car’s headlight beams. To the credit of the promoters, the cyclist is shown using a headlight.

There is only an e-mail address on the Web site for contact information but, judging by the uniquely nonstandard curve-into-curb edge stripes on the roadway, I think this video was shot here in Massachusetts.

And, the bicyclist in the video rides in the door zone and makes a left turn from the right curb on a red light. The car following him also turns left on red. I’m glad I wasn’t sharing the road with these people!

Now, looking at this photo, http://www.lightlanebike.com/prototpye_pics_008.htm , I can confirm Massachusetts — the famous Citgo sign near Fenway Park (go, Sox!) is visible in the background.

Right here in Massachusetts! Maybe the perpetrators are associated with a certain educational institution on the Charles River, of which I’m an alumnus! What a thought…

One response to “About the laser bike lane…

  1. Pingback: Wow, it’s a laser! | John S. Allen's Bicycle Blog

Leave a Reply

Your email address will not be published. Required fields are marked *

Please answer this to show that you are a human!... *