Comment by giantg2 | Hacker News Reader

Comment by giantg2 | Hacker News Reader

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"The typical way for pedestrians to cross a busy highway for example is via a bridge"

I'm not sure where you're from, but I have seen very few of these. Usually the ones I've seen are over a very busy road with few to no intersections and a lot of foot traffic. These are beneficial to the flow of both car and foot traffic instead of using long cycle times.

“beg buttons”

I'm sorry, but that is some extreme spin. What do you think happens at traffic signals? Those signals use sensors to identify when cars come up to them. These sensors don't work for pedestrians lacking large amounts of metal to trip the fields. So yeah, they have a button to tell the machine they want to cross. Usually, the lights change just as fast if not faster than if a car pulls up at a red light.

When in a shared space, everyone must wait their turn. If you don't, you end up with people steeping out in front if cars and people running red lights. Taking turns is part of a functioning society.

Pedestrians are second class in most crossings though (at least in the UK).

For traffic lights that are always green except when a pedestrian wants to cross we do have the “beg button” but the problem is that there is usually a reasonable delay before the lights turn red to stop the cars.

Obviously there needs to be some sort of delay between sets of red lights otherwise someone could just spend the day pressing the button and crossing all day whilst the traffic backs up. But the delay is front loaded. There doesn’t need to be such a long delay before the lights turn red if the lights have been green for a long enough period prior to that. Poor implementation.

I’m sure there’s a study somewhere where they decided to go with the pre-delay for some reason, but I’ve never found anything.

> I'm not sure where you're from, but I have seen very few of these.

Well I’m not sure where you’re from but I have seen tons of these pedestrian bridges :) wouldn’t it be better to inconvenience the car by building an overpass? The car has an engine and doesn’t get tired.

On beg buttons: I did not invent the terminology. Look it up.

Where is that?

Source for your beg button claim? I've only seen that term used with a political spin. (And yes, I tried looking it up)

You can’t have looked too hard if you didn’t find it.

Please be more charitable. I legitimately looked. All I found were biased pieces calling them beg buttons. I'm asking for an unbiased source calling them that. It seems the real term is a pedestrian call button.

The CBC is pretty objective and unbiased in their reporting : https://www.cbc.ca/news/canada/ottawa/councillor-takes-steps...

I’m sure you’ll find a way to disqualify that also, but well. By the way this was like the fourth result on a ddg search, there are many more if you care to actually look and read.

Yeah, I mean, they're quoting a politician to get the term. Ergo my stance that it's heavy spin.

In the event of high foot and road traffic you could have A or B go 3D. The fact it’s pedestrians suggests they have a lower priority.

Or that the infrastructure is cheaper

Oh now I know you are a troll. It would be cheaper to build level intersections with traffic lights. Why then are billions spent on wide freeways, exchanges, overpasses when it’s road over road but when it’s about pedestrians then sure, do whatever is cheapest because they’re already on foot, how much of a hurry can they be in?

I'm not a troll. What do you think is cheaper - an overpass or a foot bridge?

Neither. Both cost significantly more to build and maintain than at-grade intersections. That's part of the reason more and more grade separated highways are being demolished and replaced with surface roads.

Yes they cost more than at-grade. At-grade is the most common. I'm talking about high volume areas for both traffic and pedestrians, usually involving 6+ lanes of traffic (even if the roads are at-grade) or a need for foot traffic to cross an interstate where no road intersections exist. These are scenarios where at-grade crossings would be extremely inefficient and probably cost more in wasted time, fuel, etc than the infrastructure cost of an elevated foot bridge. Some places like Vegas have the money to erect elevated foot bridges on the strip even though the intersections are at grade. Of course many places don't need dedicated foot bridges when existing overpasses exist with sidewalks, such as with 676 in Philly.

At high volumes of foot traffic the high cost of sending pedestrians up over a footbridge is greater over the lifetime of a bridge than doing the same to cars.

Consider the physical risks pedestrians takes vs cars over a bridge, the lost time on each journey for cars vs people going over a bridge, fuel costs from additional car trips vs additional fuel cars expend going over a single bridge etc.

Even relatively modest levels of foot traffic pay for a cheap bridge that’s going to last ~50 years.

A troll bridge for car-centric people who can’t see beyond their little metal box with wheels would be cheaper of course.

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