While out on a business trip to Washintgon, I noticed several signage differences vs. what is in the HB:
1. WA525 Spur. It is signed on at least one BGS ( https://www.google.com/maps/@47.9235319,-122.290186,3a,75y,213.43h,84.24t/data=!3m6!1e1!3m4!1sWQZFCY1m68MVrWMSQfkajA!2e0!7i16384!8i8192 ), but I never saw it any reassurance markers, nor on any blades. Of course, there's really only one place for a blade (exiting the Boeing Store/factory tour). Northbound, it is simply signed "TO WA 526 Paine Field Rd"
Oh man, I didn't realize that was signed. I actually clinched it a few years ago in the northbound direction, and didn't see any signs, but it never occurred to me to check the other direction. That's enough signage for it to be added to TM (WA isn't really big on posting reassurance markers anyway), so I've gone ahead and added the route.
2. WA 531. Signage appears to show it ending at the entrance to the county park (about 1/4 mile south of the HB end at Rose Rd). The sign here ( https://www.google.com/maps/@48.1365773,-122.2816616,3a,75y,164.29h,69.72t/data=!3m6!1e1!3m4!1sidt5m2QxsB7dfo5Ej7T7Yg!2e0!7i3328!8i1664 ) is the backside of the "BEGIN WA 531" sign, but GMSV didn't go any further north. I believe that's also the 0 milepost.
WSDOT's GIS map confirms this. I've extended it to the Wenberg County Park entrance. I've also recentered a few waypoints and added one at 67th Ave NE since that's a pretty major arterial that was begging for a waypoint.
3. WA526/527/99/I-5. This one is ugly. Signage shows all 3 state routes ending at this traffic light ( https://www.google.com/maps/@47.9193731,-122.2093494,18.17z ), which serves no I-5 ramps directly. In fact, the only I-5 access available from here are for NB WA99 or 527 to SB I-5 (via Broadway), or NB I-5 from Broadway via WA527. Yes, you can do WA99 or WA526 to I-5 north here, too, but both routes have other (free-flowing) ramps available. I guess I-5 South to WA 527 South goes through here, too. As I said, this one is ugly.
Not sure what to do about this one. Perhaps someone who was involved with creating WA's state routes could weigh in and explain why it was done this way? I'm assuming it's basically a 1PPI situation, right?
I do agree that this interchange is really ugly. Has anyone else dealt with a similar setup in their regions? If so, how did you end up dealing with it? Personally, I'm leaning towards just not doing anything...
4. Also, I'm wondering about a point around 78th St on WA 522. This sign ( https://www.google.com/maps/@47.6860973,-122.3142546,3a,75y,254.62h,104.32t/data=!3m6!1e1!3m4!1s4KpYaBos9pBJBJft9PkwFA!2e0!7i16384!8i8192 ) heading southbound is horribly misleading, and it's not obvious what to do at the gore until it's too late.
Sure, I can add a waypoint there. (named RooWay) While I'm at it, I'll also do some other fixes to this route, mainly including fixing the issue where points are placed on side streets when they really should be on nearby arterials (e.g. 135thSt and 65thAve), something that is a problem with many WA state routes. Also, I've recentered a few waypoints and shaping points along this route as well.
5. I'd also like to suggest a point at Houser Way/Bronson Way (the east end of the one-way couplet in Renton on WA900). Renton is awful for signage/reassurance shields. You might get one ahead of your turn, but that's about it.
Looking at the state highway log and the GIS map I mentioned earlier, it actually looks like there is a gap in the route between WA 167 and I-405. It seems like WSDOT turned that section of WA 900 back to the city of Renton. Did you see any signs for WA 900 at all through downtown Renton?
Anyway, I've created a pull request for all changes except #3 and #5.
https://github.com/TravelMapping/HighwayData/pull/5007