Hi Viz/Reflective gear at night

2 watchers

Cerrertonia Mar 2018 10:15pm, 22 Mar 2018 7,813 posts	0 Cerrertonia I walk a couple of miles each day through Cambridge after work. In early December, I tried to count all of the cyclists with no lights - and stopped when I got to 100. It amazes me there aren't more deaths. As a pedestrian, you can struggle to cross the road safely in some places due to the difficulty of spotting cyclists. Clearly, no amount of lighting would have helped in this specific case (the driver was not even looking at the road, and the car is not using just visible light for obstacle detection - so something has gone very wrong.) But we certainly can change the odds in our favour.
Duchess Mar 2018 11:13pm, 22 Mar 2018 7,757 posts	0 Duchess Why would you not take steps to improve your chances of avoiding death or serious injury? As a pedestrian or cyclist, whether or not I'm visible isn't going to protect me from the unobservant distracted driver. But it's sure as hell going to help the one who's trying their best (there's a reason that those vehicles have flashing lights, and a reason why road and rail workers wear mandatory reflective clothing).
ChrisHB Mar 2018 11:49pm, 22 Mar 2018 16,349 posts	0 ChrisHB And the reason teachers (I suppose) wear hi-viz+reflective in the swimming pool?
Nellers Mar 2018 6:43am, 23 Mar 2018 32,358 posts	0 Nellers 2 separate issues for me: 1) Yes we all need to take some responsibility for our safety and being visible at night is a part of that BUT some drivers are just dangerous and with so many cars on the road that small proportion is still a lot of deadly metal boxes going to fast to be safe 2) The Uber/robot driver element is newsworthy because it's different. If this had been "pedestrian killed by human driver not reacting" it wouldn't even make the local news because it happens all the time. I don't think this means that self-driving cars are a bad thing. Humans are terrible at assessing risk. Trains are still hugely safer than driving but after any train crash people decide not to travel by train and get into cars where they are much more likely to be killed. People don't wear hi-viz stuff because they know what they're doing and believe they'll stay safe. Every time they make it home safely it reinforces that belief. The ones who are proved wrong don't generally get a chance to amend their behaviour in future.
larkim Mar 2018 6:58am, 23 Mar 2018 4,223 posts	0 larkim The number of pedestrians or runners injured when they are running on pavements must be vanishingly small. If that's where you're running whilst you're free to wear hi viz I honestly can't see the real need. Much of my nocturnal running though is on country lanes with no footpaths so enhancing my visibility is fairly important!
The_Saint Mar 2018 10:29am, 23 Mar 2018 6,193 posts	0 The_Saint We had a similar kind of discussion at my club where someone felt that they could dress all in black and be invisible with impunity because they ran on pavements at night. The next club run at night in suburban Cardiff I counted every occasion that I crossed anything that vehicles could use and gave up counting when I got to 100. As for the idea that visibility doesn't matter, why are road signs reflective? Why do cat's eyes exist? Why do cars have lights? The logical contortions some people are going through is hilarious.
Chrisull Mar 2018 4:35pm, 25 Mar 2018 12,467 posts	0 Chrisull I studied computer vision at university, hmmm the idea that it might be more "robust" than human vision amuses me. It is better at specifics, of course. But they certainly don't have a heat sensor thrown in or radar. (they might have a radar separately for parking etc) It is "vision" as such, and is built up in a similar way to the way we understand vision (or rather it used to be when I was at uni - we were taught how the human eye works as a precursor to understanding how computers model vision). If you wonder why we don't have conscious AI yet, that's because we don't understand consciousness. It relies on defining shapes of different colours from different backgrounds and discerning movement. Someone wearing black against a black background is going to harder to detect, if not invisible in certain circumstances, and as I mentioned the last fatality (Tesla) had a coincidence where the white sky was the same colour as a white truck. (or rather the visual software failed to distinguish between the two). tesla.com
The_Saint Mar 2018 11:01pm, 25 Mar 2018 6,194 posts	0 The_Saint My lecturer on machine vision referred often to how hard the problem is by saying that if we attempted to "solve" the problem by naively constructing a lookup table of every conceivable object then there would be more entries than there are atoms in the visible universe. I am glad that at least one other person understands why for example the SAS would wear black clothing in a night operation rather than reflective jackets and is able to draw the correct conclusions from this.
Cerrertonia Mar 2018 11:21pm, 25 Mar 2018 7,827 posts	0 Cerrertonia Chrisull - the recent fatality did not involve a Tesla. It was an Uber car (a modified Volvo) using LiDAR technology. A pulsed laser (in fact several) is scanned across the scene and an array of sensors detects reflections, so that a 3-D representation of the scene is built up instantaneously. It absolutely does not rely on discerning movement and should be able to see as well at night as it does by day. I would be astonished if the LiDAR had failed to detect the woman with the bicycle, regardless of her choice of clothing. The problem will be with what Uber's software did next. Tesla is pretty much the only autonomous vehicle not using LiDAR currently. They prefer radar (because less affected by smoke & haze) and ultrasonic detection, in addition to optical cameras.
MudMeanderer Mar 2018 10:28am, 26 Mar 2018 1,820 posts	0 MudMeanderer sciencedirect.com