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Light Traffic

senseable.mit.edu

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Re: Light Traffic

#111

Post by adrianmonk »

These slots look way too small in the animation. Every slot needs a bit of a safety buffer. Getting t-boned is more dangerous than getting rear-ended.

So it seems like they should be trying to amortize that cost by grouping cars together, both horizontally (side by side) and vertically (front to back).

So in other words, have a cluster of, say, 5 or 10 cars that cross the intersection together.

That can be done by adjusting the speed of cars well in advance of the intersection to group them, so it's not necessary to come to a stop as with stoplights.

Re: Light Traffic

#112

Post by iambateman »

maxander wrote: post #41

So a system that requires all vehicles on the road to have flawless sensor and communications systems can achieve some improvement over current-day technology (from the paper, approximately a "doubling of capacity" for intersections with this implemented.) This is a profoundly uninteresting result, given the current-day technology in question is "a dozen lights attached to a timer." Add devices that are several order…

The Benz Patent Motorwagen had a top speed of 10 mph, roughly equivalent to a horse+carriage.

It will take time to iterate to get to the 4x-10x improvements we all hope to see.

Re: Light Traffic

#113

Post by halbritt »

jakobegger wrote: post #69
jakecopp wrote: post #64

Earlier quoted context omitted.

Even OpenCV running on a Raspberry Pi can pick out cars in a moving image - a bad offline solution (with a sensible fallback) would be better than a timer. On a large remote setup I think you are right though.

OpenCV on a Raspberry does not sound like something that is reliable and easy to deploy. It‘s a long way to go from something that you hack together in the living room to something you can deploy on hundreds of traffic lights, that works in every weather, that can easily be configured for different use cases, and that can be serviced by the technicians.

It can be:

https://resin.io

A Raspberry Pi is a surprisingly useful and cost effective device when it comes to IOT. Most industrially hardened devices of similar capacity cost a bit north of an order of magnitude more.

There are really only a couple of things that would need to be addressed, a good weather-tight case that allowed for heat dissipation, decent storage (most microSD has a short lifespan), and a good 5v power supply.

In many cases, designing a system that is cheap, expendable, and expected to fail is way less costly than the alternative.

Re: Light Traffic

#114

Post by ilyagr »

perennate wrote: post #29
w0de0 wrote: post #3

What about pedestrians? For me, a future in which vehicles have more control of our public spaces is worse than the present, no matter the efficiency of the arrangement. Many American cities are notorious for being designed for the automobile, not the human. Let's not double down. More Ramblas!

Cyclists are also not considered. Maybe the intersection looks like this once you add pedestrians and cyclists: https://vimeo.com/106226560 Edit: also worth checking the earlier discussion from a couple years ago: https://news.ycombinator.com/item?id=11336009

That's an awesome video, thanks!

Re: Light Traffic

#115

Post by rtpg »

sndean wrote: post #72
tomxor wrote: post #46

Earlier quoted context omitted.

> Drawing a (admittedly inaccurate) parallel with shared spaces (which are harder to navigate by sensory deprived humans than standard intersections), I'd say roundabouts (which preserve crossings) would be a more sensible short-term approach overall -- especially considering the remaining human drivers. I actually find roundabouts easier to navigate than large crossroads, I think this is partly because they actually…

It wasn't part of my driving test in Virginia, at least when I took it. I'm guessing if your state has a low number of roundabouts [0] then it's pretty unlikely you'll be tested on it. I'd be interested to hear if Marylanders (#1 in roundabouts:intersections) have it on their test. Personally, I freak out when I see a roundabout coming up, and slow down dramatically. Or, I completely avoid them. [0] https://www.cityl…

It's possible that even when slowing down the roundabout still ends up being more efficient, since you don't have as much "stop/go" action going on

Re: Light Traffic

#116

Post by mindslight »

vinay427 wrote: post #91
mindslight wrote: post #66

Earlier quoted context omitted.

"Widely" ? Maybe in altruism-display places like SoCal, where the expectation for traffic interaction is to stop and have a ten minute meeting about how to proceed so everyone can feel leave feeling superior. In general it's just called yielding , and that it happens in all four dimensions is implicit. The difference in China is that the tolerances are smaller.

Can you elaborate on where this is coming from? I know you're exaggerating, but in my limited experience I haven't noticed abnormally long yield times at intersections in southern California.

Try walking at a moving car in a parking lot, such that if both of you maintain your velocity you will clearly pass behind the car after it has passed. 9/10 times the driver will "helpfully" stop and "helpfully" wave you on in front of them, delaying both of you.

Re: Light Traffic

#118

Post by lsc »

ColanR wrote: post #16
rcarmo wrote: post #14

There's been a marked tendency to replace intersections with roundabouts and shared spaces ( https://en.wikipedia.org/wiki/Shared_space ) in many places, including the outskirts of Lisbon (as well as a few legendary mazes in Britain). There was even a BBC report on the latter (which I can't find right now, as usual, only a follow-up: http://www.bbc.com/news/uk-33303031 ). Drawing a (admittedly inaccurate) parallel wi…

re shared spaces, from the wikipedia: > Hans Monderman and others have suggested that, by creating a greater sense of uncertainty and making it unclear who has priority, drivers will reduce their speed, in turn reducing the dominance of vehicles, reducing road casualty rates, and improving safety for other road users. clearly, Hans Monderman has never driven in Mumbai, India.

>clearly, Hans Monderman has never driven in Mumbai, India.

I'm reminded of my time in Berkeley. Now, in spite of what Fox News might tell you, Berkeley is one of the most ridiculously upper class places possible. But, it's right next to Oakland, a place that... isn't.

In Berkeley? If you even look like you were about to step out into the road in the middle of the street, people would stop for you. Over in El Cerrito or Oakland? you could be in the crosswalk, and nobody even slows down.

Re: Light Traffic

#119

Post by closeparen »

notatoad wrote: post #94
closeparen wrote: post #83

Earlier quoted context omitted.

Unsustainable compared to what? New York is clearly demonstrating that it’s incapable of sustaining a subway, and it has just about the best conditions possible for such a project. You think a place that can’t even manage roads can swing a subway? Is it sustainable to all move closer together? Not if the residents of existing cities have anything to say about how those cities are governed. They don’t want the extra p…

unsustainable is an absolute, not a relative. A road network doesn't have to be unsustainable relative to anything in order for it to be full to capacity at and for there to be no room for any more roads, which is the situation New York finds itself in. It is physically impossible for NYC to have sustained substantial growth to their private vehicle infrastructure, hence "unsustainable". If they want to grow their tr…

Maintaining existing roads is certainly not beyond the economic capacity of the United States. It just costs more than you're willing to pay. That's valid, but the alternatives don't appear to be cheaper. New York also finds maintaining its subways in working order, something that's certainly physically possible, to cost more than it's willing to pay.

High density and high transportation demand are prerequisites for having a public transit system at all. And what dense US city's government isn't corrupt or incompetent?

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