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Comment by chrisseaton | Hacker News Reader

> it’s not clear to me why the various impacted cities don’t choose to ban through traffic

Can you physically turn the streets into cul-de-sacs? Where I live a lot of domestic streets are cul-de-sacs presumably to prevent too many people driving past.

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My small town did this 20 or 30 years ago with a number of residential streets that were commonly [ab]used for shortcuts. They erected barriers that consist of a curb across the roadway and a series of three or four "no entry" and "dead end" signs. Inconvenient, but it stops through traffic.

Tucson and Phoenix have another alternative. The cities are built with the main roads being a large grid. Subdivision roads are twisty and higgledy-piggledy. It's almost always too inefficient to cut through a subdivision to bother trying.

Actually can you just put traffic-triggered off-by-default red lights, similar to the ones used on highway on-ramps to trickle cars in during rush hour?

If only one or two cars are seen on the road, turn the light off. If more than that, turn it on and allow one car per green every several seconds. It will reduce throughput enough that Waze will automatically route away from it (and eventually Waze editors will have to figure out how to encode it) without affecting normal residential traffic.

For whatever reason, people don't always care about speed limits but they usually don't run red lights.

That is interesting... metered off ramps. I could see them putting one at the Eastbound 101 exit for Haskell. I see very few people exit there while I'm stuck in traffic waiting to get on the 405. I'm sure a significant number of people are following waze (it often suggests I go that way to save 4 minutes).

I don't understand why "on-ramp" metered lights aren't used in many more places.

Like enforcing easy zipper merging. Put lights on both lanes that need to merge together, out there in the middle of the freeway. Turn them off when there's no traffic.

Around my area in Sydney a few new street signs have been popping up banning traffic from driving through at certain times of the day, without actually changing the roads. The signs say for example 'No right turn 7am-10am' which is when morning traffic sneaks into the side street to get to the CBD faster.

Then I got to sit on my balcony for 6 weeks watching the traffic cops ticket one car after the other until they stopped catching people.

You can install what’s called “Modal Filters”: A series of barriers that lets pedestrians and cycles pass, but blocks cars. This slightly inconveniences local traffic, but blocks through traffic.

Near my downtown side-streets there are temporary barriers that you can actually drive around (but you know you're going against what the sign says).

I presume enforcement is always an option.

Another point, on my street there used to be horrible backup right in front of my house, but once the light near the school nearby went to a half-duplex mode, apps stopped recommending it as a sure bet shortcut. Once that happened traffic lowered considerably.

If the signs prohibit passage, Waze wouldn't be able to use that (legally invalid) route, would it?

Waze and Google Maps tend to have bad/outdated data and tell people to make illegal turns. The roads near my apartment changed over a year ago and I still see people make illegal left turns (including Lyft drivers unless I warn them about it in advance).

Speed bumps go a long way too by dropping the effective speed.

Speed is a huge problem. I make sure I don't go more than 25 through one of the shortcuts I take through a residential area and when Waze starts sending people down these roads they are extremely aggressive behind me. I'm guessing they'd be driving 40 to 50 if I wasn't in their way which is pointless because the route ends in a long line of car's trying to make a turn. When I was young I used to ride my bike through these neighborhoods - I'd be surprised if parents felt comfortable letting there kids do the same today.

My city seems to do this with more unorthodox methods: cheap out on road maintenance and engineering.

Oh sure, take that side street with all of the sunken sewer grates.

My mom’s street was riddled with potholes. We were happy when they repaved it, but blew it when they put up speed bumps.

This is partly because drivers aren't actually paying there way, and are subsidised by others a ridiculous amount.

And by raising the aggravation and discomfort levels. Some people will avoid streets with speed bumps if they can find an alternate route because they dislike them so much.

Getting a speed bump added to your street is nearly impossible in LA. I lived on a street that badly needed one. It was a double length block paralleling Wilshire, so frequently used as a bypass with many speeding drivers. I looked up the process for requesting a speed bump. They only take so many requests per year, so I had to wait a few months for the request form to open up. I marked my calendar and when the date came it required that you get signatures from 50% of the residents on your street. Since my street was almost entirely apartment buildings and a double length block, this would have been hundreds of people. I gave up. I no longer live there.

Yes, in my neck of the woods they cut off some roads used as rat runs by installing bollards. Pedestrians and bikes can still go through but car no longer can.

Yes, Portland added diverters to some of its neighborhood Greenway routes, that forcibly divert car traffic (walking and biking can still get through). It was done for basically what's talked about in the article, too many cars using local residential roads for commuting.

Really, this is a design problem with the streets and lack of effective public transportation. LA brought this onto itself.

They made a decision not to make the roads objectively worse to thwart abusers. I think calling that a design problem they brought on themselves is unfair.

It's not objectively worse, any more than road diets make streets objectively worse, or sidewalks, or protected bike lanes, or speed limits. Making roads worse for through traffic makes them better for other uses. It comes down to what your priorities are, and right now, through design, they're choosing to prioritize the very through traffic they're complaining about.

It's not unfair, and it's accurate. The design decisions the area chose as a whole, like handicapping public transportation, led to this situation. With robust public transit, you wouldn't have a huge flood of desperate car commuters driven to find any possible shortcut.

Road diets, sidewalks, bike lanes, and (correctly done) speed limits all have very nice features.

Blocking exits does not in any way improve the road itself.

It just inconveniences people that are improperly cutting through more than normal drivers.

The fact that through traffic is technically possible does not mean it is 'prioritized'.

> Blocking exits does not in any way improve the road itself.

Incorrect. It improves the conditions of the road for local drivers, as well cyclists and pedestrians. Which is exactly why Portland did it. Unless you have an alternative explanation?

> The fact that through traffic is technically possible does not mean it is 'prioritized'.

It shows that they've prioritized enabling through traffic over other concerns.

It's not all that different from road diets. Road diets usually reduce the carrying capacity of the road, making it "objectively worse", in your parlance, in the service of other goals. Diverters accomplish a similar function.

Road diets arguably make the road nicer to be on.

Blocking exits only fixes things through second order effects. The direct effect is negative. If we could stop through traffic via other means, we wouldn't want to block exits, but we would still want bike lanes and speed limits and road diets in residential areas.

Yes, just add a barrier only allowing bikes and pedestrians through.

There’s one in Los Gatos, I believe, where they did this partially. Cars can empty on to the larger street, but can’t enter from the that direction.

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