Originally Posted by
Calsun
What is overlooked is at what distance a motorist needs to see that you are in the roadway and to respond and avoid hitting you. "Suppose a driver is traveling at 60 mph (88 feet per second) and suddenly sees a pedestrian. "Normal" perception-reaction time1 for a lane incursion by a pedestrian (Green, 2000) is about 1.5 seconds. During this time, the car will have moved forward 132 feet (1.5 x 88). Cars don’t stop instantaneously, however, so the vehicle continues forward after brake depression until friction halts all motion. This would require another 150 feet and take about 3.4 seconds. As a result, the driver must see the pedestrian 280 feet and 4.9 seconds in advance."
https://www.visualexpert.com/Resources/pedestrian.html
There are also studies on what color is best during the day (dayglo yellow-green) and which is best at night when different cones are involved and there is no sunlight to illuminate the individual.
I would not trust any device with my life. There are far too many drivers who are are distracted, drunk, drowsy and/or drugged (AKA the “D” drivers) and frequently don’t react properly to unusual situations on the highway.
Overcomplicated, yet quite oversimple in this application. There isn't anywhere where a driver may legally travel 60mph and yet have pedestrians crossing in front of them. Do drivers speed? Of course. Do enough of them exceed the usual 25mph/30mph/35mph restrictions common in urban and suburban pedestrian/cyclist routing to make your assertions work? I don't think so. This is a cycling forum. A
cyclist moving crosswise OR with traffic, does not need the driver to come to a complete stop in a collision scenario. Even in your overly hyperbolic 60mph in a 25mph panic stop the cyclist only needs for the driver to scrub off 50% of their delta vee. A pedestrian probably wouldn't make it to safety but the average cyclist should. In the worst case scenario and there is car on cyclist contact, the outcome is considerably improved if the car is only traveling at 19mph. Far from zero, but yet the cyclist/pedestrian can reasonably be expected to survive a direct hit. This is why, in Europe, the laws don't focus so much on closing/passing distance, but they do insist on safe closing/passing
speeds.