Whoopsie! Sydney's road planners just discovered induced demand is a thing, after opening a new motorway.
For those outside Sydney, the New South Wales state government recently opened a new spaghetti intersection just west of Sydney's Central Business District.
It was supposed to solve traffic. Instead, it's turned into a giant car park:
"For the third straight day, motorists and bus passengers endured bumper-to-bumper traffic on the City West Link and Victoria Road. A trip from Haberfield to the Anzac Bridge on the City West Link averaged an agonising 44 minutes in the morning peak on Wednesday.
"Several months ago, Transport for NSW’s modelling had suggested traffic from the interchange would add only five to 10 minutes to trips on Victoria Road through Drummoyne and over the Iron Cove Bridge during morning peaks.
"Those travel delays have now blown out."
So what do motorists say when their shiny new road that was supposed to solve traffic instead turns into a massive traffic jam?
'Dude! Just one more lane!'
From the article:
"[Roads Minister John] Graham and his Transport boss Josh Murray appear reluctant to do what many motorists reckon is the obvious solution.
"That is, add lanes or make changes at the pinch-points that are causing the pain. A three-lane to one merge point from Victoria Road onto the Anzac Bridge, along with two lanes merging into one on the City West Link, are proving to be painful bottlenecks."
I think H.O.V. lanes are necessary, and the passenger limit should be such that traffic moves quickly in them They will require separate ramps from everyone else.
@ajsadauskas induced demand is a stupid concept. If adding options increases traffic that means your.city is not serving residents. The point of a city is all the places people can get in them, if you have no place to go then move to Montana or someplace else with noplace to go. Note that I didn't say add more lanes, lanes are not very cost effective'
The reason adding one more lane is wrong is by the time slowdowns occure people are already packing cars in 6 times more dense than is safe and so you need not one more lane but 6 times as many lanes. That is expensive no matter how you look at it. (And probably requires layers of bridges and tunnels)
@fuck_cars@sydneytrains@urbanism@ajsadauskas That is about the right level of freeway for a city (entire MSA) of about a million people. I believe that the picture is for a city population of 7 million.
The point is, if you spend the money on other modes of transport you can serve those residents without the negative externalities that come along with more traffic.
You mean mixing businesses and residential units in the same walkable neighborhood like we’ve done for thousands of years? That would never work! We must maximize commuting distances in order to reduce traffic and commuting times.
You really need to put a sarcasm tag on that. I almost got whiplash.
My city is doing the same thing. They let developers build out exclaves around the city and then ask the city to annex it. There seems to be no limit to how stupid the city council is about this. The latest one is on a hill with no water, police, fire, or school services that got annexed. Now the city has to build out everything. The ROI to the city is in the range of centuries based on the tax revenues. Add in that it’s 100% commercial district free and now we’ve added an eternal car snake on a tiny two lane road into town.
We’ve gotta start building some mixed use density or all of this infrastructure is going to collapse.
Things like "add more roads, they'll de-congest" are natural assumptions, and wrong.
But there are many counter-intuitive things,
and it is incompetent to pretend that every manager, authority, whatever, everywhere, is going to somehow, magically, independently discover that they are counter-intuitive & need to be managed backwards to one's unconscious "reasoning".
It's like trying to get somebody to understand countersteering...
Until they understand that you're literally riding the bike on the side of the tire, it can't make any sense.
Counter-intuitive functions need to be catalog'd, organized, and systematically defeated by school-kids, or in job-training, or ANYthing.
The costs of not doing-so are compounding too much.
Perhaps a Required Lessons for each domain, & each job within that domain...
It’s like trying to get somebody to understand countersteering.
Yep.
Until they understand that you’re literally riding the bike on the side of the tire, it can’t make any sense
Wait, what? Countersteering is about manipulating the contact patch relative to the center of gravity. The side of the tire has relatively no relevance.
@jedsetter@ajsadauskas@fuck_cars@sydneytrains@urbanism
Not even that; the additional lanes already exist, they're just signposted so confusingly that people are avoiding them and instead crowding onto what's now intended to be a local road
The tunnel sign-posted as "City, Port Botany ✈️ [toll]" goes to Anzac Bridge, toll-free. If you're used to taking Victoria Road to Anzac Bridge, you should take the tunnel.
In particular, I recall a simple graph example where you'd have two parallel roads with some traffic on them. And then you create a link between them, aiming to improve the situation. However, the link gets jammed and the overall situation gets worse
While the money sold have been spent on public transport, it’s a bit fucking premature to put this down to induced demand - the tangled mess has been operating for what - like 3 business days? People are getting confused and doing silly bullshit. It’s a problem, but it’s not induced demand.
Induced demand is a thing, and it’ll almost certainly be relevant here - there’s no need to lie about it - give it a minute to settle first. This is the benefit of being correct - there’s no need to be dishonest.
I came here to point this out and love the way you stated it. Confusion, hesitation and unnecessary lane changes are what create traffic. There has never been a major highway development in history that didn’t cause at least some short term issues. We should give city planners a bit more credit than that
Edit: you’d think that in a fuck cars community, of all places, we’d all be able to agree on this basic principle. We’re apparently infested with six idiot trolls who think cars don’t cause traffic and that induced demand isn’t real.
The volume of cars is a scale factor that determines the impact of traffic causing behaviors and conditions for free flowing highways (no traffic lights, stop signs, etc.). Following too closely and improper lane changing are two specific behaviors that actually create slow downs. There are numerous models that simulate this.
Yes, yes, I’m well aware of how it works (I’m a former traffic engineer IRL). Although it’s true the behaviors trigger the slowdowns, it’s the traffic volume that creates the conditions where switching to the congested flow regime becomes possible.
In other words, if high traffic volumes aren’t present, those behaviors don’t have that consequence, and moreover, if high traffic volumes are present, the free-flow regime is such an unstable equilibrium that some kind of event (even one as minor as a driver briefly tapping their brakes) triggering a shift away from it and to the congested regime is inevitable. It’s the volume that’s the essential condition, not the behavior.
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