3dis vs 2dis

[jbnv]

I think the key to "letting it go" is to realize the entire 3dus system is pretty much arbitrary and useless. Nobody would ever get on US191 and keep driving, hoping they would eventually hit US91. The roads had little relationship to each other beyond intersecting at some arbitrary point. 2dus routes are not "parents" and 3dus routes are not "children".

Ditto 71 and 171, which have never actually intersected. The only benefit of the 3dus numbers is having them conform loosely to the grid (190 is south of 280 is south of 270, etc.).

It would have been much better if there was an sensible system to the 3dus routes, say 1XX routes on the east coast and 9xx routes on the west. As it stands, the extra digit is meaningless to the traveller, so it might as well be something random like 425.

You mean a regional numbering a la Florida? Would have made sense. The first digit of a 3dus could have matched the ZIP code regions (with 0zzzz and 1zzzz sharing 1uu).

[Henry]

I'd give US 138 a pass because there was in fact a route called US 38. Not so with I-238, especially now that the Embarcadero Freeway no longer exists, and I-480 could've been recycled in the same way that I-880 was. And there has never been an I-38!

[bassoon1986]

I think the key to "letting it go" is to realize the entire 3dus system is pretty much arbitrary and useless. Nobody would ever get on US191 and keep driving, hoping they would eventually hit US91. The roads had little relationship to each other beyond intersecting at some arbitrary point. 2dus routes are not "parents" and 3dus routes are not "children".

Ditto 71 and 171, which have never actually intersected. The only benefit of the 3dus numbers is having them conform loosely to the grid (190 is south of 280 is south of 270, etc.).

Actually it is pretty likely that at one time US 171 followed US 79 & US 80 from it's current terminus to downtown Shreveport to meet US 71. I think the us-ends website may describe that scenario. And I wish I could find he black and white picture I've seen somewhere online that showed those three shields on Texas St. downtown.

But yes, I definitely agree the 3dus doesn't do much anymore. Many are not even good alternate routes to their "parent." US 371 is one of many that has an awful through routing.

[bugo]

OK 266 is a spur off of OK 66 (it has been recently extended to I-44)
OK 351 is a spur off of OK 51
OK 364 is related to US 64
Former OK 159 was a spur off of US 59
OK 131 is a spur off of OK 31
OK 128 is an extension of AR 28
OK 199 is a spur off of OK 99