Eastern WA. But I escape a lot.
Yaaagh!!! They’re spreading. I see them on I5 southbound going up Southcenter Hill toward Kent, second lane fronm the curb. I noticed they look like cuts in the concrete and they are placed at each expansion joint. I don’t think they are there stritly because the concrete is swelling or tilting because the road is even worse at the top of the hill and they are only on the steep slope.
The cuts are so narrow, I suspect they are some kind of inspection or test in preparation for repaving. Anybody recall a late night lane closure on Southbound 5 at Southcenter Hill? Funny there are no cuts or whatever they are on the Northbound side.
How about some empirical data? I was actually stopped in traffic for a bit on southbound I-5 just before the S. 188th Street exit, in the second lane, right over the marks. For the first time, I saw that they did in fact cross each joint in the concrete, and were only in the second lane as the other lanes didn’t have the same visible joints. They were clearly cut out, had some sort of rod placed as noted in an earlier post, then refilled with concrete. As soon as that type of expansion joint was no longer used, the marks disappeared.
My friend drove to Seattle last weekend and I convinced him to take some pictures. Looks like scr4 was right all along.
Well, your brother was wrong. Which is a classic example of why a picture is worth a thousand words; I think what your brother thought you were describing was recessed reflectors, but that’s not what was actually under discussion.
Well, even with a horse’s mouth, garbage in is garbage out… 
Good job, Mr2001!
Awesome! Now I can see that I was wrong. Traveling at highway speeds (and maybe because I wasn’t wearing my glasses), I didn’t notice that the “dents” were on expansion joints, and they’re not as close together as I thought. But those still photos make it nice and clear 
Thanks to your friend for the photos, and thank you for asking him/her!
Sweet. Better photos than I could have taken. Lovely day too!
Okay, it makes perfect sense now that those repetitive recessed areas in the Freeway are from dowel bar retrofits to maintain the level of the mating road sections, but it’s my understanding that they were originally filled up to the level of the surrounding road surface and relatively smooth. I assume they have been worn away over time by the constant beating of vehicle tires, studs, etc. to make the sunken divots we experience today, so why can’t they be refilled to level so they’re not so annoying to drive on?
If there’s no other cars around I frequently drive in the left lane to avoid them, but that’s technically illegal. Also, I would think that being lower than the surrounding surface they would accumulate water, freeze, and cause more of a hazard and further deterioration than otherwise. Does anyone have a contact that works for the State that might know why they don’t refill these annoying things, if they are indeed dowel bar retrofits? They’re a total pain.
Here’s some footage of the hot -n- heavy action of dowel placement.
However the one time I saw it in action, it was more of an assembly line process. There was a large flatbed with the dowels driving slowly along the closed lane with a pack of workers scooping up handfuls and dropping them into the pre-cut slots. A concrete pourer brought up the rear. Not nearly as precise as the video shows.
I drive to Yakima frequently from Seattle to visit family. I cannot upload pictures to show because I am a new user to this site. My 16 year old is driving to Yakima this afternoon and was asking so we looked it up and found this site. I will upload a picture when site allows me to do so.
I was wondering why nobody posted a Google Street View but then I saw this is a zombie thread. Nonetheless, it looks like this is what everyone’s talking about:
And yes, those are retrofitted dowel bars. Maybe they didn’t use the best grout and that’s wearing away faster than the surrounding concrete. Regarding @racer72’s comment, there are ALSO recessed reflectors, but only along the painted lines. So there’s two different things going on.
Welcome to the SDMB! Actually, no users can upload pictures to this site, even the crusty old-timers. We usually deal with this by uploading them to imgur or the like instead, and then linking them from there.