I sit above a pretty busy intersection and get to witness the madness and regular accidents of rush hour traffic heading out of downtown on a daily basis.
I think simply shimming an extra second or of intersection clearing time between transitions would go long way towards addressing the apparent dangers of light timing.
Activating traffic signals and pedestrian signals simultaneously results in drivers who try to 'beat' the pedestrians off the curb.
Activating perpendicular traffic signals too close traffic/pedestrian signals puts the cross-traffic in danger of being hit by the people trying to time the light.
Add a second or two, end up with <5 fewer light transitions per hour.
Though, on a related note, what I see cause more accidents and general bullshit than timing lights is the ridiculous amount of cellphone use that happens in motion and particularly at intersections.
Every day I see someone stop at the red light below me and immediately start fiddling with their phone, as the light turns green and the fiddler proceeds to hit the gas irrespective of what is happening in the road directly in front of them - pedestrians, gridlock, presidential motorcade only to run into something or panic stop seconds later if they're lucky.
At first this seemed inexplicable..."Can't these people see?"
Upon thinking about it, I'm guessing they actually can't or more accurately don't see. That the fraction of a second they have to hit the gas before getting a chorus of horns or a rear-ending is simply too short to take in even major changes in the scene in front of them.
If you live in a culture where disobeying traffic signals is common (especially non-drivers...say in China...), you observe that people become much more cautious about light transitions. I always cringe driving back in the states and just going as soon as a light turns green.
A kid rushing after a ball into a crowded street in the US is probably dead meat. In China, they have a much better chance of surviving because drivers are used to that crap (likewise for pedestrians and crazy drivers). Though I would venture that the fatality rate is still much higher China (I've personally seen people get hit and killed).
This is surprisingly common: people's behaviour around technology is awful, so the solution is more technology! As much as I agree that taking idiot humans out of the decision-making process is a good idea, I wonder what unintended side effects self-driving cars will have.
Also, it's not so difficult to not use your phone at a light, and in many jurisdictions, it is illegal to use a phone or other electronic device (which is not a driving aid, e.g. navigation systems) while in care and control of a vehicle. My wife, for example, refuses to even look at her phone while driving, even if stopped at a light; extremely frustrating for me when I'm trying to get her to pick me up somewhere, but easily defensible when you hear stories like this.
In the end, all of these stories seem to come down to selfishness, ignorance, and carelessness. If people were more aware of the world around them, then these things would be significantly less common. I feel as though technology isn't going to fix that until we've basically eliminated humans entirely from all decision making.
I've never seen an intersection that didn't have some amount of time where it was red in all directions during a light change. I can't find references to back it up right now but I'm pretty sure that in cases where this period is extended you end up with drivers adapting and driving through a stale yellow that they would have previously stopped for.
In most of California it seems that the next set of lights turns green as soon as the previous set turns red. In Ontario, Canada I believe there is a 2 or 3 second delay. I don't think that I've noticed any difference in the behavior of people around yellow lights except for the fact that in California it seems people are more willing to run red lights, and the intersection is almost never clear when the next green light happens (unless, of course, traffic is sparse). In Ontario, Canada the intersection is almost always clear when the next green light happens.
Add a second or two, end up with <5 fewer light transitions per hour.
Perhaps this is backwards? If the problems occur mostly at transitions, shouldn't we try to minimize transitions with really long lights? Of course at some point there isn't enough room on the block to accommodate stopped traffic...
The point here isn't to have more transitions, but rather to put a delay between a yellow going red and a red going green.
People often treat yellow lights as 'Better hurry up!' and the worst of those people will end up in the intersection when the light turns red; if, at the same time, the other light goes green, impatient people will rush the light and accidents (or near misses) can occur. A driver who rushes and then slams on his brakes when he realizes that someone was still in the intersection can be hit by the person behind him who expected him to go, but didn't expect him to stop.
Extremely long lights will make things worse by increasing driver frustration and eliminating the feasibility of left-turns when an intersection doesn't have an advance left turn. In many downtown areas (of the ones which I've been to), there are no (or few) advance left turns; this means that, typically, you will wait at a red light, then wait at a green light, then turn left on the yellow light. If they're on top of things and you've advanced into the intersection, the person behind you could also manage a left turn.
Longer lights means fewer yellows, which means fewer left turns, which backs up traffic even worse.
That's a bit like suggesting that autopilots and automatic landing systems are the wrong solution to reducing air accidents. The only difference is that automatic flight systems in aircraft were introduced in the past and self-driving cars will (presumably) be introduced in the future, but the validity of the approach to the problem is basically the same.
No, my thinking goes along the lines of society wanting/needing to use less cars not more. hence I would be more for mass transit type solutions rather than packing more cars onto the road more (space) efficiently.
It wasn't directly related to traffic accidents in the article, but to what the parent comment said at the end.
Well yes, using cars for urban transport is a bad habit that we should never have got into, and we should now be trying to get out of. But it's logistically and politically impossible to get rid of all cars overnight. There are a number of things we can do to cut down on car usage. Self-driving is something we can do to cut down on the fatality rate per car. Each of these is a partial solution. Partial solutions are complementary, not exclusive.
But self driving cars are a great way to cut down on the number of vehicles on the road via very cheap, highly utilised automated taxis. Vehicles should last a lot longer too because the autopilots would make fewer mistakes such as over-gunning engines, stalling, braking late and terrors more sharply, etc. they could enable huge efficiency savings.
I think simply shimming an extra second or of intersection clearing time between transitions would go long way towards addressing the apparent dangers of light timing.
Activating traffic signals and pedestrian signals simultaneously results in drivers who try to 'beat' the pedestrians off the curb.
Activating perpendicular traffic signals too close traffic/pedestrian signals puts the cross-traffic in danger of being hit by the people trying to time the light.
Add a second or two, end up with <5 fewer light transitions per hour.
Though, on a related note, what I see cause more accidents and general bullshit than timing lights is the ridiculous amount of cellphone use that happens in motion and particularly at intersections.
Every day I see someone stop at the red light below me and immediately start fiddling with their phone, as the light turns green and the fiddler proceeds to hit the gas irrespective of what is happening in the road directly in front of them - pedestrians, gridlock, presidential motorcade only to run into something or panic stop seconds later if they're lucky.
At first this seemed inexplicable..."Can't these people see?"
Upon thinking about it, I'm guessing they actually can't or more accurately don't see. That the fraction of a second they have to hit the gas before getting a chorus of horns or a rear-ending is simply too short to take in even major changes in the scene in front of them.
Self-driving cars can't come soon enough.