Comment by moralestapia
6 days ago
50 km/h to 30 km/h on a city commute doesn't make a substantial difference.
If you're willing to risk people dying just to get to your preferred McDonald's three minutes earlier, then the problem is you.
6 days ago
50 km/h to 30 km/h on a city commute doesn't make a substantial difference.
If you're willing to risk people dying just to get to your preferred McDonald's three minutes earlier, then the problem is you.
I wonder if the "5 minute city" approach would also help. Just zone the cities so that getting that burger doesn't even involve driving at all, just a brisk walk?
Of course it would, but mention that and America loses its mind.
Good for the environment. Good for your health (more walking). Good for traffic safety (less fatalities). Good for the health care system. Good for your mental health and feeling of connectedness to your community. Good for the economy (more local businesses and less large box monopolies means more employment).
And on the cons side… hurts oil execs, national and international retailers, and people who define freedom as having to pay $5 to exxon to get groceries.
I can't see how a 20 km/h difference can't not make a difference averaged over so many commuter-miles, but I'm not a city planner or traffic engineer.
Because it's not an average speed but max speed. Higher max speed in traffic doesn't make an average speed higher because it makes the traffic less smooth.
For example in Switzerland on some highways during rush hour the speed limit goes down to 80km/h. They analyzed it and it turns out it's an optimal speed limit for throughput.
Within a city it really doesn’t matter because it averages out.
I’m an avid cyclist in a US city. There’s a pretty large radius around me in which driving is <= 5 minutes quicker, not counting time to park. Plus cycling often leaves me directly by my destination. I can’t imagine how much more convenient it would be in a dense European city.
Anyways, what the hell is everyone in such a hurry for? Leave five minutes earlier. Cars are absolutely magical. Drivers sitting on mobile couches while expending minimal effort? Magical. So, ya know, adding a few minutes should really be no big deal. Which I doubt it does.
Big, open highways are different. Or at least I’d imagine them to be.
You don’t need to be either.
Suppose a trip is 5km.
At 50km/h, that trip takes 6 minutes.
At 30km/h, that trip takes 10 minutes.
In practice, this naive way of calculating this doesn’t even reflect reality, because odds are the average speed of a driver through Helsinki was around 30km/h anyways. Going 50km/h between red lights doesn’t actually make your trip faster.
> Going 50km/h between red lights doesn’t actually make your trip faster
Except when it does, due to horrible traffic engineering practices.
There were a pair of one-way streets in the downtown of my city. Both attempted to have "green wave" setups for the lights. One worked pretty well, the other was okay, but whatever.
The problem was that the road itself was signed at 30 mph, but the lights were timed at 40 mph. It literally encouraged people to speed if it were not too busy (e.g., after business hours).
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> In practice, this naive way of calculating this doesn’t even reflect reality, because odds are the average speed of a driver through Helsinki was around 30km/h anyways. Going 50km/h between red lights doesn’t actually make your trip faster.
This is a wonderful explanation.
Though I've lived in Europe (Düsseldorf and London), my default sense of urban density is still American so it was hard to fathom such a low potential average speed. In London, I didn't bother with a car.
I'm not an advocate for speeding in the cities, but this example is really bad - it says my trip time will be extended by 66%! For a really short one, it doesn't matter, but when you drive 40 minutes initially, it's really unacceptable for most.
30km/h is actually above the average travel speed you typically achieve in a big city, if you take traffic jams into account.
Yes, take Lake Shore Drive in Chicago. 4 or 5 lanes in each direction, 30mph speed limit, and average speed is often about 5-10mph.
Exactly my point.
The average commute is not entirely within the streets with the 30 km/h speed limit. City planners usually try to route car traffic away from residential areas and places with large numbers of pedestrians, through arterials, freeways, and the like, which will have a higher speed limit.
Most of Amsterdam is 30 km, including through roads. But it's Amsterdam through roads, so it's mostly two lines one way, a dedicated tram track in between, trees that separate the road from a bike path and all that. Actual in-district roads where unsupervised 8 year olds are cycling to school and back are 15 km/h.
> 50 km/h to 30 km/h on a city commute doesn't make a substantial difference.
This seems like a weird argument. If your commute is an hour at 50 km/h then it's an hour and 40 minutes at 30 km/h, every day, each way. That seems like... quite a lot?
That's not how it works. It's a 30km/h speed limit for one kilometer in your local neighbourhood until you hit the first through road, then it'll be 50km/h / 60km/h / 80 km/h / 120 km/h as usual, and another one kilometer at 30 km/h at your destination.
In other words, it's 2km at 30km/h plus 48km at 80km/h, versus 2km at 50km/h plus 48km at 80km/h. That's a difference of 1 minute 36 seconds.
Here for example is a map of Amsterdam (click on Wegcategorie en snelheid). Inside the block it's 15 km/h, on blue roads are 30, red roads are 50. The map doesn't color-code the highways, as they don't belong to municipality, but they are 100. https://maps.amsterdam.nl/30km/
It's like that since last December and was somewhat controversial when introduced (expanded), because muh freedoms, but not the kind of enduring controversy.
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2017 Helsinki speed map for reference: https://www.hel.fi/hel2/ksv/Aineistot/Liikennesuunnittelu/Au...
(in support of the above thesis)
This is about driving in a city: you spend most of your time accelerating, decelerating, and waiting at intersections. 30 vs 50 km/h doesn't make much of a difference - travel time does not scale linearly with it.
Whether you can hold the maximum as the average doesn't mean there is no proportionality. If you're traveling at 50 km/h and then have to come to a stop and accelerate again your average speed might be 25, but if the maximum speed is 30 then your average speed might be 15.
Which city is an hour long drive at 50km/h?
It’s city centre driving that the article talks about.
You can drive through London for an hour in mostly 20mph (~30km/h) zones. Thing is, you're unlikely to be averaging anything even like 20. Even when the limit used to be 30 you weren't either. My old car averaged 16mph, & that included trips out of town at motorway speeds.
When the 20 limits were first introduced, lots of people would speed & overtake, but then you'd catch them up at the next traffic light & the one after etc.
I know London's quite an extreme case, but all a 20 limit means in a lot of stop/start urban areas is that you travel to the next stop at a speed which is less hazardous should you hit something/someone, with far more time to react to all the unpredictable things which happen in busy urban areas, thus decreasing the chances of hitting anything in the first place.
Yeah, it's mildly boring, but driving in cities pretty much always is. Just put on some music or a podcast and take it easy.
See, the real problem is that people cover too much distances daily. 50km is more than Luxembourg is wide where it's narrowest. They probably don't commute internationally every day there.
I think people allocate themselves an hour or what their comfortable time is to commute and travel whatever distance they can cover in that time. If something is too far, they either move closer or pass on it. The exact mode, distance and speed can all vary, but what's budgeted for is time.
> See, the real problem is that people cover too much distances daily.
Which is why most of this is really a housing problem. If you make it too difficult to add new housing in and around cities, people have to live farther away, and in turn show up to the city in cars.
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Actually a lot of people do, because it's cheaper to live and shop on the other side of the border.
The speed limit is not 30km/h for the entire trip.