Amsterdam Switches to 30 Km/h on 80% of its Roads

As for Amsterdam - it's a tiny city area wise, 30 km/h is mostly core. All highway limits stays the same. Map they provided show 50 km/h outside of the very centre. I'm glad for them if that make a difference. As a side note I didn't enjoy Amsterdam public transport (again comparing with Montreal).

As a related fact in Montreal that stretch of the road https://maps.app.goo.gl/dgG8avYABUgbZ7BTA was switched from 50km/h to 40km/h. As you can see it has fences on both sides, so it's hard to justify safety reasons here.

lolwut? i haven't gotten a single camera-based ticket, ever - many decades of driving in the US - unlike say Italy where every time i drive (about once in 5 years) i seem to break some stupid minor rule and get a photo ticket

Basically if you put Germans and Dutch people together, they'll argue which country has the best car infrastructure. The grass is greener on the other side. Dutch people say you can go faster on German roads, while Germans say that the dutch speed limits make traffic more smooth and logical.

Either way, once you drive out to the highway you can theoretically lock the cruise control to 100 km/h [1] (including on intersections) until ~5-10 min from your destination.[2] That's not a bad country for cars!

[1] Except eg. Amsterdam ring-road which is 80 km/h. Exception that proves the rule.

[2] I did say theoretically. Roads ARE busy and you may need to tap the brakes sometimes. Though... in practice I'm willing to bet that on any given day some number of people actually manage to achieve this by accident. (outside rush hour and with a little luck)

And- apparently it gets interesting if you start computing throughput in terms of per person instead of per vehicle.

Unfortuantely maths and the real world don't always add up..

You could absolutely make traffic better by increasing lanes somewhere where the population was generally decreasing at a decent rate, of course, but population growth is another source in many places - you can't build enough new capacity in a lot of areas to keep up with the growth.

The fundamental problem is that cars are a very space inefficient way of moving people - that's why we see this problem in cities but don't tend to see it in rural areas (because they don't have many people but have plenty of space, so the volumetric inefficiency doesn't matter), and why you don't tend to see the issue much with rail other transit - since they have so much passenger capacity for the space they take up, if there's induced demand there's often scope for increasing service frequency.

If you don't like them, try any of many other sources. Quoting "If you build it, they will drive: Measuring induced demand for vehicle travel in urban areas" (2018) at https://www.sciencedirect.com/science/article/abs/pii/S09670... :

> There is little dispute among transportation researchers that expanding highway capacity increases vehicle use. This phenomenon is commonly known as induced demand, and it demonstrates a fundamental economic principle: individuals tend to consume more of a good as the price of the good falls. In other words, wider highways increase traffic speeds and reduce the time cost of driving, thereby inducing additional vehicle travel. In the short run, when residential and employment locations are fixed, faster peak period highway speeds attract drivers from alternate routes, modes, and times of day. Then, in the long-run, faster speeds encourage additional social and economic behavior in areas made more accessible by the new highway capacity, which further increases traffic volumes.

> Research studies since the 1960s have suggested that, because of induced demand, the hoped-for benefits from highway expansion tend to be short-lived and do not provide lasting relief to traffic congestion. Early studies by Downs (1962), Smeed (1968), and Thomson (1977) go so far as to argue that, over time and without any other offsetting deterrent, rush-hour traffic speeds tend to revert to their pre-expansion levels. The finding has even been dubbed the Fundamental Law of Road Congestion (Downs, 1962), which asserts that the elasticity of vehicle miles traveled with respect to lane mileage is equal to one, implying that driving increases in exact proportion to highway capacity additions.

How much does a road cost?

"The 2km stretch of the Bayfair to Baypark upgrade on SH2 south of Tauranga was already costing $70 million per kilometre - two to three times more than usual." https://www.rnz.co.nz/news/national/425683/highway-costing-7...

That's about $25 million per km in the usual, or about 10x more expensive than this bike path.

"The cost to build a new road link in Christchurch’s west has ballooned 41% to $25 million." says https://www.neighbourly.co.nz/public/christchurch/broomfield... and that appears to be under 2km of road works., so $30 million/km.

"The $290m 16-kilometre Northern Corridor motorway extension, funded by the government, cost $18m a kilometre to build, while the second stage of the southern motorway worked out at $20m per kilometre." says https://www.stuff.co.nz/the-press/news/124611551/building-10...

In the US it costs about US (20230) $4 million/mile to put in a new small urban road. https://kobobuilding.com/cost-to-build-a-road-per-mile/ . That's about NZ$4 million/km, if I did the conversion correctly, and still more than the bike path.

> that is $750 per person

Now do the same calculation for roads.

Also, "About $187m of that will come from the Government’s coffers, not ratepayers" says https://www.stuff.co.nz/the-press/news/127422028/christchurc... so your math should be adjusted. I work it out to

  ((301_000_000 - 187_000_000) / 405_000) + (187_000_000 / 5_258_000)
  = NZ$317 per Christchurch resident

It looks like they're going to start using speed cameras now instead of police enforcement (they certainly don't want to use police enforcement here, that would clearly turn out badly). They're trialing "racing cameras" to supposedly catch the kids drag racing at night, but it is obviously a way to introduce enforcement of the 25 mph limits without doing road redesign and to generate revenue.

The result is pretty obviously going to be regressive taxation, because Seattle/Washington State runs everything via regressive taxation. So the traffic cameras are not being setup on W Seattle Bridge to catch white collar people commuting to the office, but are put on W Marginal Way which are going to catch blue collar workers.

I'm just waiting for liberal Seattle to wake up one morning and realize the DOT is funding their bike lanes by regressive taxation through traffic camera enforcement, falling on the lower class and minorities, and see if their heads explode or not.

There's a way to do it right like Amsterdam where they've already built all the infrastructure and done all the road diets, we're doing it the ass-backwards way by dropping the speed limits and setting up traffic cameras.

It worked!

Basically, it's irresponsible to drive faster than 30 km/h anywhere with a significant number of pedestrians. The risk of serious injury and death rises quickly above that speed, and human drivers cannot react quickly enough at higher speeds. You can justify a bit higher speed limits on major streets with significant traffic, as pedestrians tend to be more attentive when crossing them. But even then, the limit should be 40-50 km/h, as road capacity decreases and noise level becomes unacceptably high at higher speeds.

50km/h is for athletes or going down steep hills. If you're training for the tour de france in some random neighbourhood in Amsterdam, I think you're doing something wrong.