Fundamental rule of traffic: building new roads makes people drive more (2015) • Hacker News Board

Re: Fundamental rule of traffic: building new roads makes people drive more (2015)

#41

Post by whoisnnamdi » Fri, Dec 28, 2018, 8:57 PM UTC

This is an important point that is commonly overlooked.

Traffic is a sign of something. It’s a sign that the benefits of transportation outweighs the costs of transportation. Given this, high traffic often implies that there is pent up demand out there - more cars that would be on the road right now if only the roads could support it.

When more roads are built, this unlocks some of the pent up demand, as the cost of transportation has effectively declined due to more available roads.

However, this reduction in cost / hassle etc and the previously pent up demand may be so large that in encourages much more driving, such that in equilibrium the traffic could be nearly as bad as before.

Re: Fundamental rule of traffic: building new roads makes people drive more (2015)

#42

Post by belenos46 » Fri, Dec 28, 2018, 8:58 PM UTC

fabioborellini wrote: post #6

paulsutter wrote: post #2

It's called "elastic demand" and it just means that roads are useful. The Boring Company has a twofold solution (a) charge for usage, and (b) build to 30 levels or more to meet demand

In the Old World we have public mass transit. One vehicle can transport a thousand commuters, and it does not need to be stored in the most desired area of the city for the duration of a working day. Sometimes it looks like the Silicon Valley is trying to solve transit problems either against the laws of physics and economics or, alternatively, ignoring solutions that were there already in the 1800s.

Likely the latter, and for that we can largely thank large motorist groups in the US. Michelin comes to mind, as they created their "Michelin star" metric to give people a reason to drive places, and then lobbied like hell to create town/city layouts that mandated driving.

A hundred years later, driving is a massive part of US culture, and we have trouble seeing the problem because that's "just how things are".

Re: Fundamental rule of traffic: building new roads makes people drive more (2015)

#43

Post by kodablah » Fri, Dec 28, 2018, 8:59 PM UTC

komali2 wrote: post #7

I'm visiting my hometown of Houston after now having lived in SF for just under 3 years, and my partner and mine most common debate thread as we sit in Houston traffic is - what did Houston do differently, to get these uniquely Houston traffic problems? Is it "Houston's" fault, or the fact that it has an extra 2 million people? Does it actually have 2 million more people, or did it just octopus across the entire regi…

> what did Houston do differently, to get these uniquely Houston traffic problems?

Not sure they are uniquely Houston, and definitely not their explicit fault, but I'd say the issue is (obviously) large concentrations of people going to the same area. The DFW metroplex has some traffic issues like any metros, but not to the same extent as e.g. Houston despite being a larger metro (but smaller city). And that's the point. Were Houston's employers to fan out even more than they already do, you might see the suburb-to-suburb commutes that many other sprawls enjoy. Maybe there are plenty of people that live in Katy and work in the Woodlands or vice-versa. Not having to ever even enter the city on a regular basis is very welcoming to those who hate traffic.

Re: Fundamental rule of traffic: building new roads makes people drive more (2015)

#44

Post by JimboOmega » Fri, Dec 28, 2018, 8:59 PM UTC

Kalium wrote: post #26

JimboOmega wrote: post #4

Is this even a problem? People are given an opportunity to do something and then they do it. That's way better than new roads going unused, isn't it? I like congestion charging alright, which the article advocates at the very end, but it has a habit of being regressive - it's easy for me, as a software engineer, to show up at work at 11AM, but that might not be the case for those who can less afford to pay those char…

> Is this even a problem? People are given an opportunity to do something and then they do it. That's way better than new roads going unused, isn't it? It's a problem insofar as building more roads is often sold as a way to resolve traffic problems. When traffic expands to fill all available roads, this solution is an expensive way to not fix anything. There are probably more useful options, and faster ways to waste…

But it is making trips possible that weren't before; it's not strictly money going down the drain. I have trouble seeing a fully utilized resource as "a waste".

Saying "traffic will be solved by this!" is clearly misleading. But those extra cars on the road must be benefitting, or else they wouldn't make the trip.

Re: Fundamental rule of traffic: building new roads makes people drive more (2015)

#45

Post by TuringNYC » Fri, Dec 28, 2018, 9:01 PM UTC

tafda wrote: post #32

TuringNYC wrote: post #8

The more intelligent approach to building roads is one i've seen in Washington DC. While the metro system isnt perfect, they allocated a portion of the highway to rail (middle track between both directions on the highway.) This way, the community expanded outwards via longer and longer highways and there was an obvious way to eventually simultaneously also expand the metro system outwards. They did this with the Oran…

Transit works better if it is where people are going rather than where it is convenient to build - for example, downtown Falls Church VA instead of the freeway median. Building densely around the stations can drive ridership. See: Tokyo, Hong Kong, Singapore. Of course, building in more congested areas is more expensive. Freeway median transit is no panacea (though better than nothing).

Well the idea is that the major highways are a good indicator of where people are going. If you build a major high way, and then widen it, chances are good its where people want to travel along.

With respect to getting to downtown Falls Church VA, that is more a last mile problem. One I dont want to dismiss, but not something a commuter rail can solve. The commuter rail does pretty well at getting people to several major job districts (DC, Tyson's Corner)

Building commuter rail along highway medians solves a different problem -- the NYC problem where a city fiddles around for 40yrs figuring out where to dig a tunnel and eminent domain problems.

Re: Fundamental rule of traffic: building new roads makes people drive more (2015)

#46

Post by baddox » Fri, Dec 28, 2018, 9:02 PM UTC

40acres wrote: post #36

Why are roads an elastic demand but it seems that other transportation methods, like light rail, aren't? I've seen cases of quite a few expensive lines and rail-stops that have lower than expected utilization, but it seems like new highway roads and lanes get immediate use. Is it down to the fact that there is simply more "freedom" with regards to roads over rail?

I think it’s because in the US cars effectively “won.” Even if mid and long distance passenger rail were more of a thing, you’ll have to rent a car at your destination anyway.

In other words, with just a car you can get anywhere you want in the continental US in 2-3 days. With just passenger rail (or commercial air travel, etc.), you can get to passenger terminals in a lot of places, but that’s about it.

Re: Fundamental rule of traffic: building new roads makes people drive more (2015)

#47

Post by mklingen » Fri, Dec 28, 2018, 9:03 PM UTC

komali2 wrote: post #7

I'm visiting my hometown of Houston after now having lived in SF for just under 3 years, and my partner and mine most common debate thread as we sit in Houston traffic is - what did Houston do differently, to get these uniquely Houston traffic problems? Is it "Houston's" fault, or the fact that it has an extra 2 million people? Does it actually have 2 million more people, or did it just octopus across the entire regi…

> Where's the money coming from?

The federal highway program. Highways are heavily, heavily subsidized by state and federal dollars. That's why their true cost isn't born on drivers, and it's something that greatly exacerbates the problem of urban planning the U.S that leads to vast sprawl, urban decay, hell for walkers/bikers and environmental degredation. If all highways were toll roads, most would cease to exist and our cities would become denser, doubly so if all those highway dollars were diverted to public transit.

Re: Fundamental rule of traffic: building new roads makes people drive more (2015)

#48

Post by Kalium » Fri, Dec 28, 2018, 9:03 PM UTC

JimboOmega wrote: post #44

Kalium wrote: post #26

Earlier quoted context omitted.

> Is this even a problem? People are given an opportunity to do something and then they do it. That's way better than new roads going unused, isn't it? It's a problem insofar as building more roads is often sold as a way to resolve traffic problems. When traffic expands to fill all available roads, this solution is an expensive way to not fix anything. There are probably more useful options, and faster ways to waste…

But it is making trips possible that weren't before; it's not strictly money going down the drain. I have trouble seeing a fully utilized resource as "a waste". Saying "traffic will be solved by this!" is clearly misleading. But those extra cars on the road must be benefitting, or else they wouldn't make the trip.

That's an excellent and very wise question! It's one that deserves careful study. At which point different ways of accomplishing the same goals can be compared and the best option(s) selected. I think we can agree this would be a reasonable, level-headed, approach to make informed decisions.

This may be slightly different from a political cycle that spends ever-increasing amounts of resources on roads without examining if the results obtained provide a reasonable level of value for money. Or indeed address the issues that drove the construction of additional roads in the first place.

Broadly, fully utilized resources are not always an ideal goal. For example, my experience is that meeting rooms in offices are almost always in constant use, no matter how many there are. This may not be the same as all uses of meeting rooms being desirable and efficient uses of the time and other resources used. I know I have been in meetings, enabled by a sizable of supply of meeting rooms, that could have been handled much faster with a handful of emails.

Re: Fundamental rule of traffic: building new roads makes people drive more (2015)

#49

Post by Simon_says » Fri, Dec 28, 2018, 9:05 PM UTC

disantlor wrote: post #27

Simon_says wrote: post #18

Earlier quoted context omitted.

> it's easy for me, as a software engineer, to show up at work at 11AM That's the point -- we should incentivize people who can time shift to do so thereby alleviating traffic for those who can't.

yes but that’s also what makes it regressive

By that same logic, purchasing hamburgers is regressive.

Re: Fundamental rule of traffic: building new roads makes people drive more (2015)

#50

Post by mklingen » Fri, Dec 28, 2018, 9:06 PM UTC

JimboOmega wrote: post #4

Is this even a problem? People are given an opportunity to do something and then they do it. That's way better than new roads going unused, isn't it? I like congestion charging alright, which the article advocates at the very end, but it has a habit of being regressive - it's easy for me, as a software engineer, to show up at work at 11AM, but that might not be the case for those who can less afford to pay those char…

It's a problem because it's a positive feedback loop. More highways = more traffic, which leads people to want to build more highways to supposedly ease congestion, and this continues ad infinitum. Our cities grow more spread out, less walkable, and less sustainable. Overall it makes our cities worse both for the people who live there and the environment.

If we didn't subsidise highways so much, demand for them would be reduced, and it would make more sense to build denser housing and provide public transportation.