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What are those dents in I-90 outside Seattle?

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Re: What are those dents in I-90 outside Seattle?

#21

Post by engineer_22 »

WalterBright wrote: post #10
bombcar wrote: post #8

Earlier quoted context omitted.

The US interstate moves insane numbers of huge ass-trucks that weight one billion metric pounds each or something. Anything less than airport-grade concrete dies instantly, and then dies again when it invariably freezes to -40° Kelvin, because fuck physics when shit gets cold.

The reason for the interstate trucks is the taxation system that punishes railroads for owning their right-of-way. The trucks cause by far the most damage to the highways, but taxpayers subsidize that with the gas tax. Trucks also do not pay property tax on the highways. Long haul freight should be done by loading the semi's trailer onto a flat car, and picking it up near the destination. Another myopic government de…

Trucks pay much higher tolls. Tolls are based on axles and weight.

Re: What are those dents in I-90 outside Seattle?

#23

Post by lostlogin »

legitster wrote: post #11

Man, reading this format does not make me miss forums. It's easy to opine for the "internet of old", but I for one do not miss having to post a car problem to a Ford Escort message board and maybe getting an answer after 3 days of being told I am an idiot.

Now you can get that response in minutes or even seconds, and in a more readable format with push notifications and advertising.

Re: What are those dents in I-90 outside Seattle?

#24

Post by the_mitsuhiko »

haunter wrote: post #4
mbauman wrote: post #3

A little funny to not link to the comment that had the answer — they're dowel bar retrofits. https://en.wikipedia.org/wiki/Dowel_bar_retrofit

If a Wikipedia page about a technological topic (so not a person, place etc) has a very few languages available (in this case 2) then it always makes me wonder how other countries in the World solve the same issue. This seems like a very US thing for example but maybe I’m wrong

I was wondering the same thing recently. In Austria and some countries around a pretty popular road replacement system is called "fly over"[1] which has nothing to do with an overpass in the US, but is basically a small bridge put on top of a highway to repair the road surface underneath without interrupting traffic.

It was mislinked on Wikipedia to overpass and while trying to figure out what it should link to I learned that this concept just does not really exist in other countries.

[1]: https://www.waagnerbiro-bridgesystems.com/references/fly-ove...

Re: What are those dents in I-90 outside Seattle?

#25

Post by josephcsible »

engineer_22 wrote: post #21
WalterBright wrote: post #10

Earlier quoted context omitted.

The reason for the interstate trucks is the taxation system that punishes railroads for owning their right-of-way. The trucks cause by far the most damage to the highways, but taxpayers subsidize that with the gas tax. Trucks also do not pay property tax on the highways. Long haul freight should be done by loading the semi's trailer onto a flat car, and picking it up near the destination. Another myopic government de…

Trucks pay much higher tolls. Tolls are based on axles and weight.

But not nearly higher enough. Driving on roads damages them in proportion to the fourth power of per-axle weight, which is about 17,000lbs for a fully loaded semi and 2,000lbs for a car. To put that in perspective, if the toll for the car were $0.25, it'd have to be over $1,300 for the truck for it to be fair in that sense.

Re: What are those dents in I-90 outside Seattle?

#26

Post by vl »

modeless wrote: post #2

I haven't seen these in a decade but I knew what they were talking about instantly. I used to wonder what they were all the time. I sure didn't expect to get an answer randomly on the HN front page. They did a really good job installing these. They look like they would be bumpy but I never felt them at all.

>They did a really good job installing these.

It really depends on the car and suspension! In regular car driving over them is fine. In motorhome vibration is so strong that I go in the left lane, otherwise it's two hours of crazy shaking.

Re: What are those dents in I-90 outside Seattle?

#27

Post by vl »

mbauman wrote: post #3

A little funny to not link to the comment that had the answer — they're dowel bar retrofits. https://en.wikipedia.org/wiki/Dowel_bar_retrofit

Looks like filler is gone from these on I-90 because driving in motorhome over them (V-8 F-53 chassis) leads to crazy vibration. Regular car is fine.

Re: What are those dents in I-90 outside Seattle?

#28

Post by modeless »

vl wrote: post #26
modeless wrote: post #2

I haven't seen these in a decade but I knew what they were talking about instantly. I used to wonder what they were all the time. I sure didn't expect to get an answer randomly on the HN front page. They did a really good job installing these. They look like they would be bumpy but I never felt them at all.

>They did a really good job installing these. It really depends on the car and suspension! In regular car driving over them is fine. In motorhome vibration is so strong that I go in the left lane, otherwise it's two hours of crazy shaking.

This was a decade ago. Perhaps the replacement concrete is wearing away now.

Re: What are those dents in I-90 outside Seattle?

#29

Post by usrusr »

Ancalagon wrote: post #16
bombcar wrote: post #8

Earlier quoted context omitted.

The US interstate moves insane numbers of huge ass-trucks that weight one billion metric pounds each or something. Anything less than airport-grade concrete dies instantly, and then dies again when it invariably freezes to -40° Kelvin, because fuck physics when shit gets cold.

I love the hyperbole in this comment! :D

Allow me to single out the metric pound, which is defined as precisely a billionth of the weight the local road surface can withstand. Noteworthy for being one of the few units that work for both mass and weight because the local gravity is conveniently factored in.

Re: What are those dents in I-90 outside Seattle?

#30

Post by fredoralive »

Gordonjcp wrote: post #6
haunter wrote: post #4

Earlier quoted context omitted.

If a Wikipedia page about a technological topic (so not a person, place etc) has a very few languages available (in this case 2) then it always makes me wonder how other countries in the World solve the same issue. This seems like a very US thing for example but maybe I’m wrong

There's one bit of jointed concrete road that I know of in the UK, a few miles where I live on the A90 near Laurencekirk. It's bloody awful, like driving over smashed paving slabs. In my big old Range Rover with its off-road air suspension and massive reinforced tyres it's a noisy and uncomfortable couple of miles. In a modern vehicle with ultra-low profile tyres and incredibly stiff "sporty" suspension it must be li…

There’s an interesting blog post about the UK’s unloved and out of fashion concrete Motorways here: https://www.roads.org.uk/blog/diamond-rough which notes that the US seems to occasionally grind the surface of concrete roads, whilst in the UK [INSERT WHATEVER THE HIGHWAYS AGENCY IS CALLED THIS WEEK][1] don’t (barring recent trials) leading to people driving on rough decades old surfaces. Although ISTR it was the expansion joints that were the real annoyance? But I haven’t personally encountered concrete roads in the UK in decades, it’s more of a thing from when I was a kid.

[1] Or local / devolved authorities etc.

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