Interstate 8 in Arizona - why isn't Yuma a control city westbound?

[Bobby5280]

Yeah, Grand Junction checks all the boxes. It's a big enough city. I-70 and US-50 join/diverge there. Two rail lines also meet there.

[MattHanson939]

Yeah, Grand Junction checks all the boxes. It's a big enough city. I-70 and US-50 join/diverge there. Two rail lines also meet there.

Also, other than Grand Junction, there are no other biggish cities along I-70 going west from Denver; that's why it has to be a primary control city in that case.  Going east from its western terminus at I-15 is signed for Denver; and I would use Grand Junction as a secondary from the Utah-Colorado state line (i.e. dual-signing Grand Junction / Denver).

Going west from Grand Junction, it's signed for Utah.  And I think once it crosses into Utah, St. George can be the control city from there since it's the next biggest city closest to the route's western terminus.  In that case, St. George should be a secondary on I-15.

[Bobby5280]

For overhead green signs it's a judgement call whether to list 1 or 2 control cities. Regarding ground mounted mileage marker green signs, I like at least 2 or 3 control cities or highway junctions listed. IMHO, the ground mounted mileage marker signs seem pretty rare. But those kinds of signs can be good at reminding a motorist they may be approaching an important junction.

It's okay for Grand Junction to be listed as the lone control city on an I-25 ramp going to WB I-70. Farther down the road a ground mounted mileage sign can be helpful at letting them know that exit to US-40 in Empire is just a few miles ahead.

[thenetwork]

Yeah, Grand Junction checks all the boxes. It's a big enough city. I-70 and US-50 join/diverge there. Two rail lines also meet there.

Also, other than Grand Junction, there are no other biggish cities along I-70 going west from Denver; that's why it has to be a primary control city in that case.  Going east from its western terminus at I-15 is signed for Denver; and I would use Grand Junction as a secondary from the Utah-Colorado state line (i.e. dual-signing Grand Junction / Denver).

Going west from Grand Junction, it's signed for Utah.  And I think once it crosses into Utah, St. George can be the control city from there since it's the next biggest city closest to the route's western terminus.  In that case, St. George should be a secondary on I-15.

It use to be Green River On I-70 from Grand Junction to the state line (There is still one side-mounted BGS that remains in the field).  Once you crossed into Utah, I-70 west was signed as either Thompson Springs or Green River, then Richfield and Cove Fort (with a few random Las Vegas signs in the wild as of several years ago).

Green River is signed because not only is it where I-70 and US-6 split, but that is about where the 105‐mile NO SERVICES Gap begins on I-70. Richfield is pretty much the only decent-sized town that exists along 70 in Utah.

[kphoger]

It use to be Green River On I-70 from Grand Junction to the state line (There is still one side-mounted BGS that remains in the field).  Once you crossed into Utah, I-70 west was signed as either Thompson Springs or Green River, then Richfield and Cove Fort (with a few random Las Vegas signs in the wild as of several years ago).

Green River is signed because not only is it where I-70 and US-6 split, but that is about where the 105‐mile NO SERVICES Gap begins on I-70. Richfield is pretty much the only decent-sized town that exists along 70 in Utah.

I prefer Salina over Richfield, because it's at a US Route junction.  But honestly, nothing other than Las Vegas or maybe St George needs to be signed as a primary west of Green River (US-6/191).

[MattHanson939]

It use to be Green River On I-70 from Grand Junction to the state line (There is still one side-mounted BGS that remains in the field).  Once you crossed into Utah, I-70 west was signed as either Thompson Springs or Green River, then Richfield and Cove Fort (with a few random Las Vegas signs in the wild as of several years ago).

Green River is signed because not only is it where I-70 and US-6 split, but that is about where the 105‐mile NO SERVICES Gap begins on I-70. Richfield is pretty much the only decent-sized town that exists along 70 in Utah.

I prefer Salina over Richfield, because it's at a US Route junction.  But honestly, nothing other than Las Vegas or maybe St George needs to be signed as a primary west of Green River (US-6/191).

I-70 is an interesting case because it's the only interstate in Utah that signs small towns as control cities whereas on I-15, I-80, and I-84, they sign control cities the same way that Arizona does.  But Denver is signed on the overhead for I-70 east from I-15 and makes it on to some distance signs.  It also amazes me that on the other interstates, they don't even bother signing secondary controls (smaller cities in-state like Provo or St. George) at the smaller interchanges, or even dual-signing them with primary controls on most BGS. 

That being said, I think St. George should be the primary control city on I-70 west from the Colorado state line; Green River and Salina can be secondaries, IMO. And at the western terminus, the overhead for I-15 south can be dual-signed (St. George / Las Vegas)

[mrsman]

This is where using a state as a control city is helpful. Signing it as Utah works for pretty much the whole state.

Guess I never responded to these "Utah" suggestions. (Just quoting this one as it's the shortest response.) I hate control states in general, but at least can understand them when you're close to a state border. Given that Utah is 250+ miles away from Denver, then I really hate the idea. I don't know the exact numbers obviously, but I would bet that 99.9% of the traffic heading west on I-70 from Denver is not heading to Utah. Grand Junction is fine, but if we were going to change it to anything, I'd almost prefer Vail or Silverthorne since so much of the traffic heading out of Denver is going to the mountains for outdoor recreation.

The main reason I don't like state controls is the lack of specificity.  Often there are many points within a state and there could be more than one conceivable way of getting there.  A city denotes a very specific location and is thus a better choice.