Opening the door of a parked car can present a sudden immovable obstruction to an approaching cyclist, forcing them to brake, swerve, fall off, crash or in the optimum case run into the path of another vehicle.

However, it can prove difficult to accurately judge the speed and range of an approaching target using the door mirror.

There is a maneuver called the "Dutch reach" which requires the driver to reach across their body using the hand furthest from the door to operate the release catch. This forces them to swivel their head and upper body, bringing an approaching cyclist into their peripheral vision.

But this is still far from ideal, as without extra effort the target is only visible to one eye rendering parallax inoperative.

With the new BorgCo laser targeting graticule, this effect is overcome. When the slack in the door release linkage is taken up, the laser powers up and projects a calibrated grid onto the rear window, directly in the driver's sight-line. By comparing the "ticks" on the line with the apparent magnitude of the cyclist, the approach speed can be estimated and a time-on-target calculated, allowing the door to be flung wide at the optimum moment - just enough time to swerve (thus preventing any damage to your vehicle) but not enough time to brake (thus ensuring maximum damage to the cyclist).

Once the victim has been despatched, the door handle is released and the projection blinks out; thus when the emergency services arrive to scoop up the remains for disposal and rinse away the blood, the situation looks just like any other tragic road accident. The driver can even claim "But I did the Dutch Reach like you're supposed to ..." and any witnesses may well be able to confirm this.

Then you can go home and post the video from your in-car DVR as a warning for other two-wheeled kamikaze merchants.
-- 8th of 7, Jul 09 2019

This would work well with MaxCo.'s DFPDIDWOTCDRIFOY*, which has a calibrated-grid-recognising optical system and projects a 2W laser.

(*Device for permanently damaging idiot drivers who open their car door right in front of you. Marketing are working on a better name, but for the moment it's selling well in Wales, where it means "bacon seven sandwich of unimaginable proportions".)
-- MaxwellBuchanan, Jul 09 2019


You could back this up with some Dutch courage.

Or as my distant ancestor on my mother's side Hans Jacob Biedert is reputed to have said, "Heinekin!"
-- normzone, Jul 12 2019



random, halfbakery