Stephen Woodcock, “The maths of congestion – springs, strings and traffic jams“, Phys.org (via my dad):
How can one report filed with the NSW Major Project register predict 20,000 fewer cars per day on a section of Parramatta Road, while other reports within the Roads and Maritime Services state that no significant reductions are likely to be seen?
It is very easy to chalk up some of these differences either to wildly overoptimistic developers potentially misleading themselves and others to get a project approved. Similarly, it is sometimes alleged that feasibility studies might be influenced by political biases or pre-established views on the merits of roads or public transport schemes.
While these factors may well influence some decision making, one thing that is often missed in the reporting of such studies is the sheer complexity associated with analysing such networks. Assuming all roads are connected, the behaviour of a whole network can be hyper-sensitive to how individual parts, even seemingly minor ones, function.
A poor estimate of traffic flow in one section of a network can lead to hugely different behaviour across the whole system. Furthermore, even the simplest networks can have the potential to function in some extremely surprising and often counter-intuitive ways.
It is very easy to believe that if a traveller is offered the choice of two routes for a journey that the addition of a third choice should not worsen his/her travel time. If the new route is slower, the traveller could simply ignore the new route and make the same choice as before.
As the German mathematician Dietrich Braess pointed out, this is not always the case. Increasing the capacity of a network can, perhaps surprisingly, decrease the efficiency of journeys around it even without increasing the number of trips made, as was pointed out in a recent article…
This paradox is not simply a mathematical quirk or one which can be neglected by network analysts. There are a number of examples where removing roads – rather than building news ones – has improved transport networks.
Probably the most famous example of this comes from South Korea. When the motorway network around Seoul was reworked to remove some of the 1960s-built roadways, the the result was significantly reduced transit times throughout the city. This was not because of fewer journeys through the city, rather a more efficient distribution of cars across the remaining network.
Similar phenomena have been observed during road closures in New York City in the United States and in Stuttgart in Germany.
The Economist, “Technology in New Zealand: Kiwis as guinea pigs“:
IN MEDICINE, trials are conducted on guinea pigs, rats, mice and rabbits. In digital businesses, tests are performed on New Zealanders. Their country is proving the perfect location for software firms, social networks and app developers discreetly to try out and refine their products…
New Zealand’s relative isolation means that if a product needs to be modified significantly to fix faults or make it more appealing to consumers, word of its teething troubles is less likely to spread, thereby discouraging customers elsewhere from trying the improved version. If a firm finds that a particular product, or a new feature added to an existing one, is a resounding flop in New Zealand, it can quietly be dropped without having much effect on the company’s overall reputation.
Simon Vincent, “The Ride to Wigan Pier – a story of kids, bikes, and beer“, Cycle Action Auckland:
Cycling along the cut was always a joy. The path was not smooth; its rough surface allowed us to jump and practice our wheelies. It did, however, have its dangers. The overgrown brambles narrowed the path and the thought of ending up in the cut was not a pleasant one. Water quality was not something we thought of in those days, but we did worry that lurking in those murky depths lay piscine danger – a giant pike, known as Big Bess, that had snapped many an angler’s line hunted here. And, more improbably, the story that a unscrupulous pet shop owner had discarded his stock of piranha in the canal was doing the rounds at school
We rode and we rode. We rode so far the accents along the tow path changed again and again. We called out “Any luck?” to those fishing on the banks, and bartered with bargies – we would open the locks for them in exchange for our shandy money.
A bicycle was our passport to the wider world and we loved the freedom it gave us.
Joseph Stromburg, “Highways gutted American cities. So why did they build them?” Vox:
So why did cities help build the expressways that would so profoundly decimate them? The answer involves a mix of self-interested industry groups, design choices made by people far away, a lack of municipal foresight, and outright institutional racism.
“There was an immense amount of funding that would go to local governments for building freeways, but they had little to no influence over where they’d go,” says Joseph DiMento, a law professor who co-wrote Changing Lanes: Visions and Histories of Urban Freeways. “There was also a racially motivated desire to eliminate what people called ‘urban blight.’ The funds were seen as a way to fix the urban core by replacing blight with freeways.”
This is also notable, and likely to apply to New Zealand as well:
Even though gas taxes have never fully paid for highways — a recent Public Interest Research Group report found they’ve covered between 43 and 74 percent of costs through the interstate system’s history — the widespread perception that highways and freeways are somehow self-funding has stuck around.
Simon Bush-King, “From polder to pavlova paradise“, Architecture Now (via Brendon Harre):
The Dutch experience is far removed from New Zealand. Historically, in the Netherlands most land was owned, developed and sold by national or local governments. Housing was developed at scale by private developers and few people were able to build an individual house. Housing was however, generally of a high standard and affordable. Over the last 20 years, the Dutch have introduced a greater flexibility and individual focus to the housing industry that is more relevant to the current context of New Zealand. While introducing market-led reforms, they have retained the benefits associated with building at scale, articulating a clear vision and involving all affected parties. In short, the Dutch plan – in the original sense of the word; opportunities in greenfield and brownfield sites are identified, development options are tested and the affected community is involved early in the process. Rather than lobbing grenades from the sidelines, all parties have a seat at the table. It is a process that invites certainty for communities, developers and the financial institutions involved. Public Private Partnerships are the norm. Over the years this approach has produced a number of interestingly diverse examples. Those that follow include the exciting and well-known as well as projects destined to be comfortable places in which to raise a family, rather than grab the spotlight…
Het Funen
Funen, Amsterdam, a development that combines living and working in high city-centre densities with sufficient green space on ‘Het Funen’, a former industrial zone on the edge of Amsterdam’s city centre. It is a concept that incorporates the qualities of diverse typologies: the construction of perimeter blocks along two sides, with a novel interpretation of the ‘garden city’ model to their rear.
At a different scale altogether, ‘Het Funen’ – or Hidden Delights – consists of 500 dwellings set in open space on what was a former parking lot for towed cars in east Amsterdam. A masterplan by Frits van Dongen established a perimeter block around the right angle of a difficult corner site that acts as a barrier to the busy railway line adjacent. A loose grid of 16 housing blocks is laid out within the triangle with a diversity of typologies: live-work units, maisonettes, penthouses, seniors housing, studios and houses specifically design for the disabled. There is a mix of individually owned and rental accommodation. The ground floor of the perimeter block contains commercial space. In this instance a single company – IBC Vastgoed – undertook the entire development. Usually it would be instigated by the city.
The Economist, “London skyscrapers: The ascent of the city“:
These protected views help to explain why tall buildings are rising in such a dispersed pattern. The Shard will not get neighbours anytime soon, as it is wedged between two viewing corridors. In the City, towers are scattered instead of crowding around transport hubs, as economic theory might predict. Their odd designs—described by nicknames such as the Gherkin, the Walkie Talkie and the Cheesegrater—are in some cases a means of avoiding imposing on St Paul’s. Only at Canary Wharf, which is too far east to spoil many views, do cuboid skyscrapers rub together in the way they do in other big cities.
The other reason London’s tall buildings are so oddly spread is local democracy. In the conservative borough of Westminster, the council resists almost all new tall buildings; despite soaring rents, no new skyscrapers have been built there since the 1960s. In the corporatist City, expensive architecture is prized. Almost anything goes in poor Labour-run authorities such as Lambeth, Southwark and Tower Hamlets.
Tom Vanderbilt, “Five myths about traffic“, Washington Post:
2. Faster roads are more efficient roads.
Speaking of efficiency, common sense says that when drivers are humming along at or even above the speed limit, highways are performing at their best. The German autobahn, with its (shrinking) speed-limit-free zones, is often offered as a shining example. It must be those slower drivers who are holding things up!
But as good as fast-moving roads might be for the individual driver, they are not the best for the most drivers. As data gleaned from in-pavement “loop detectors” on Washington state highways showed, those highways were able to achieve “maximum throughput” — pushing the most cars through one segment of road in a given time — at speeds that were roughly 80 percent of the posted speed limit of 60 mph. Why? At higher speeds, drivers need to allow more “headway” between vehicles, meaning more space is required per vehicle. And faster-moving traffic tends to break down more quickly, with more severe “shock waves”; it takes a lot longer to recover from a traffic jam than to get into one. I have been told, anecdotally, by traffic engineers that the left-hand “passing lane” can become congested first. (I’ll leave it to you to decide if karmic justice is at work there.)
Ramez Naam, “Renewables are disruptive to coal and gas“, Marginal Revolution:
Wind and solar compensate for each other’s variability, with solar providing power during the day, and wind primarily at dusk, dawn, and night.
Energy storage is also reaching disruptive prices at utility scale. The Tesla battery is cheap enough to replace natural gas ‘peaker’ plants. And much cheaper energy storage is on the way.
Renewable prices are not static, and generally head only in one direction: Down. Cost reductions are driven primarily by the learning curve. Solar and wind power prices improve reasonably predictably following a power law. Every doubling of cumulative solar production drives module prices down by 20%. Similar phenomena are observed in numerous manufactured goods and industrial activities, dating back to the Ford Model T. Subsidies are a clumsy policy (I’d prefer a tax on carbon) but they’ve scaled deployment, which in turn has dropped present and future costs.
Paul Krugman, “Preliminary notes on inequality and urbanism“, New York Times:
[W]hen it comes to things that make urban life better or worse, there is absolutely no reason to have faith in the invisible hand of the market. External economies are everywhere in an urban environment. After all, external economies — the perceived payoff to being near other people engaged in activities that generate positive spillovers — is the reason cities exist in the first place. And this in turn means that market values can very easily produce destructive incentives. When, say, a bank branch takes over the space formerly occupied by a beloved neighborhood shop, everyone may be maximizing returns, yet the disappearance of that shop may lead to a decline in foot traffic, contribute to the exodus of a few families and their replacement by young bankers who are never home, and so on in a way that reduces the whole neighborhood’s attractiveness.
On the other hand, however, an influx of well-paid yuppies can help support the essential infrastructure of hipster coffee shops (you can never have too many hipster coffee shops), ethnic restaurants, and dry cleaners, and help make the neighborhood better for everyone.
Gordon Campbell, “Castles in the Square“, Werewolf:
In sum, almost every major city and tourism centre in New Zealand is – simultaneously – building or extending convention centres, and is taking significant risks and investments in public money ( and public land) in the process. All these complexes are targeting much the same basic audience : the domestic and international conference markets. The economic rationale for these projects is based on the spending that the centres are being hoped to generate from (a) the hotels that will accommodate the delegates (b) the bars and restaurants that will serve them and (c) the retail outlets in which they will spend a remainder of their money.
To date, there has little or no analysis of what the net national benefit would be – if any – to New Zealand from these ventures. Constantly, the facilities will be competing with centres offshore for hosting rights to a limited number of major international conferences. Domestically, one region’s gain will be another region’s loss.
The infrastructure investments needed to support the expansion of the private car ownership paradigm. H/T @Carsharing pic.twitter.com/gwYEqTk10v
— Chris Bruntlett (@modacitylife) May 28, 2015