CO: I-70 Business routes and US 6

[mapcat]

Several of the business routes are no longer signed. Heading west on I-70, and then east on 6, I saw no indication at either end for the spurs/loops to Edwards, Eagle, Silt, or Palisade. Watkins, Denver, and Grand Junction are still signed, and Idaho Springs probably is (I wasn't paying attention this time, but it was signed last year).

US 6 has been moved off I-70 between Exit 72 and Exit 87, and continues east until rejoining I-70 at Exit 109, as shown in the HB. It is also (barely) signed to and along its old alignment in Glenwood Springs between Exits 114 and 116 (and, oddly, along a dead-end segment west of Exit 114). It then rejoins I-70 through Glenwood Canyon and departs at Exit 140, as shown in the HB.

[cl94]

Ah, yes, US 6 and the I-70 business routes. Idaho Springs is officially gone. CDOT relinquished control of most of it and, since they won't designate a route along something they don't maintain, BL 70 in Idaho Springs is no longer a thing. GIS confirms this. On the other hand, I can confirm that signage for 70 BL Denver still exists as of today.

Something else we need to update is that US 6 is discontinuous in Rifle. CDOT petitioned AASHTO to have the section between CO 13 and the eastern Rifle city line (and ONLY that section) decommissioned and it was approved. Source is here.

[oscar]

Ah, yes, US 6 and the I-70 business routes. Idaho Springs is officially gone. CDOT relinquished control of most of it and, since they won't designate a route along something they don't maintain, BL 70 in Idaho Springs is no longer a thing. GIS confirms this. On the other hand, I can confirm that signage for 70 BL Denver still exists as of today.

Something else we need to update is that US 6 is discontinuous in Rifle. CDOT petitioned AASHTO to have the section between CO 13 and the eastern Rifle city line (and ONLY that section) decommissioned and it was approved. Source is here.

Did CDOT follow up on the AASHTO approval by removing its US 6 designation, without providing an alternate route? There's an instance in another state where an AASHTO-approved relocation appears to never have been implemented. so we reverted to the old route.

We previously discussed here US 6 in Rifle, though with no firm decision on what to do about it.

As for the business routes, just a note that other states do things differently. For example, even if Colorado DOT won't designate business routes it doesn't control, California's business routes consist almost entirely of former state-maintained roads relinquished to local control (I-80BL in Sacramento is a notable exception).

[cl94]

Did CDOT follow up on the AASHTO approval by removing its US 6 designation, without providing an alternate route? There's an instance in another state where an AASHTO-approved relocation appears to never have been implemented. so we reverted to the old route.

The AASHTO documents don't indicate an alternate route, nor does one appear to exist on the surface. As signed, US 6 dies and reappears east of the city line. Of course, as far as Colorado is concerned, all of those off-Interstate segments of US routes are discontinuous. Heck. US 85 has a discontinuity, too! (Colorado Springs, jumps from the surface to I-25 at a random bridge that isn't an interchange)

[oscar]

As signed, US 6 dies and reappears east of the city line.

Were there End US 6 signs at the west and east city limits, or just a lack of US 6 signage within city limits?

There is an End US 6 sign in Mack CO, just after O Rd. where we have US 6 jumping onto I-70 at exit 11.

[si404]

When we discussed the Rifle discontinuity on AA roads, I believe we came to the conclusion that it was a terribly cackhanded way of ending state maintenance. Rifle weren't looking, as far as we knew, at removing the signs on the short bit relinquished. The conclusion we had on TM was firm - no change unless END signs appear.

Arguably the Business Loops are similar. CODoT deleting a route at the Federal level because it's now being maintained at the city/county level.

If signage shows routes/sections have been deleted, then sure change, but otherwise.

[mapcat]

Traveling on 6 between I-70 exits 72 and 109, I never saw an end sign. Or a sign directing drivers onto 70, for that matter. I’d be inclined to treat the unsigned/relinquished segments as we have 85.

[US 89]

There's also the matter of the END US 6 sign in Mack, as Oscar mentioned above. Interestingly the CDOT GIS page still has that connector road between Mack and exit 11 as part of US 6, but this segment appears to be completely unsigned.

[Duke87]

US 6 has been moved off I-70 between Exit 72 and Exit 87, and continues east until rejoining I-70 at Exit 109, as shown in the HB.

Interesting. Exit 72 did not exist prior to some time between 2012 and 2015, so there simply is no prior signage at this location to compare to. This sign off exit 75 points to US 6 going both ways along the frontage road from here as seen in 2018, roll GMSV back to 2012 and there is no such sign present. So that's one other location corroborating this!

That said, I'm seeing no mention of US 6 whatsoever at exit 87 (okay, one way or another something is missing there), and GMSV imagery between exits 75 and 87 all predates when this change would have occurred.

Also, this sign implies US 6 also goes west from exit 75 along the frontage road... okay, so what about west of there? Well, GMSV at exit 62 is too old to show if any shields have been erected there... and the old alignment is not continuously intact between exit 62 and the next interchange west.

So this situation is a bit messy and bears further research. Can you confirm (or deny) whether US 6 shields are present in the field at any other locations not linked to here?

It is also (barely) signed to and along its old alignment in Glenwood Springs between Exits 114 and 116 (and, oddly, along a dead-end segment west of Exit 114). It then rejoins I-70 through Glenwood Canyon and departs at Exit 140, as shown in the HB.

The other thing is that all the signage on this apparent segment is around exit 114. There are no signs for US 6 at exit 116.

That plus the signs pointing to US 6 down the dead end are suggesting to me that whoever put the plans together for this signage project goofed and acted on outdated info about where US 6 is... an easy mistake to make especially if some people in the areas are still used to thinking of the old road as "highway 6".


At any rate, AASHTO did not approve either of these changes... and by policy would not, since a US highway is not supposed to be moved from a higher quality road to a parallel lower quality road. Whatever CDOT is doing is rogue, if it is even deliberate (and the lack of consistency makes me question whether it is).

By the general principle of "if signage is inconsistent, defer to what is on paper" I would suggest leaving US 6 as is unless clearer and more convincing evidence that it should be routed along the surface alignment can be presented.

[Duke87]

US 6 has been moved off I-70 between Exit 72 and Exit 87, and continues east until rejoining I-70 at Exit 109, as shown in the HB.

Interesting. Exit 72 did not exist prior to some time between 2012 and 2015, so there simply is no prior signage at this location to compare to. This sign off exit 75 points to US 6 going both ways along the frontage road from here as seen in 2018, roll GMSV back to 2012 and there is no such sign present. So that's one other location corroborating this!

That said, I'm seeing no mention of US 6 whatsoever at exit 87 (okay, one way or another something is missing there), and GMSV imagery between exits 75 and 87 all predates when this change would have occurred.

Also, this sign implies US 6 also goes west from exit 75 along the frontage road... okay, so what about west of there? Well, GMSV at exit 62 is too old to show if any shields have been erected there... and the old alignment is not continuously intact between exit 62 and the next interchange west.

So this situation is a bit messy and bears further research. Can you confirm (or deny) whether US 6 shields are present in the field at any other locations not linked to here?

So I got a chance to field check some of this today.

Can confirm that there are US 6 shields at the intersection just north of exit 62, that show US 6 going east along the surface alignment but not west. That said there is no BGS mention of US 6 from I-70 here - it's only on the surface alignment itself.

Can also confirm there are US 6 shields at the intersection just south of exit 81.

The surface alignment, which I drove from exit 81 to exit 62, also very consistently has mile markers which appear to be US 6 mileage.

Based on this I would now favor moving US 6 off I-70 between exit 62 and exit 87.

[the_spui_ninja]

Sorry I haven't been keeping up on this, I kinda forgot I was maintaining Colorado... 

So just for confirmation:
the business routes in Edwards, Eagle, Silt, and Palisade should be removed
US 6 removed from I-70 between Exit 62 and Exit 87

If anyone has a problem with this speak now or forever hold your piece.

[the_spui_ninja]

https://github.com/TravelMapping/HighwayData/pull/3323