UT is changing MM's

[blueblood]

One of the selling points of using MM vs Exit Numbers on Interstates was supposed to be no changes. Well, apparently UT is physically changing because the state is increasing exit numbers on I-70 and decreasing them on I-80. For example I-70 exit 202 is now 204 and I-80 exit 143 is now 141. This makes obsolete descriptions in RV books, GPS maps, mapping programs , etc. For example, Green River in Trailer Life says exit 162 but its 164 now. Just be aware and not overshoot the intersection and have a long loop back on I-80.

 

[Ned]

Does Utah use MM or Exit Numbers?  You say they're changing exit numbers, but imply that they're changing MM.

 

[Ron]

Utah has always used Mile markers and exits are numbered according to the closest mile marker.  Supposedly the only way the exit number would change is if the exit was moved closer to another mile marker.  This has taken place a few time that I am aware of.  Maybe Phil can provide details on why they are changing things.

 

[Phil]

Maybe Phil can provide details on why they are changing things.

Maybe not.  ;D

 

[Gary RV_Wizard]

Sounds like they have recalibrated their mile markers. 

One possible explanation: the beginning of the exit ramp is often a mile or two from the actual crossroads location. If you are hurtling along at 65 and looking for Exit MM xx4 but the ramp is actually at xx2, you can easily miss it.  Renumbering the exit as xx2 aids both safety and convenience.  The drawback is that the ramp on the other side (oppositie direction) may be at xx6, so businesses have to give two sets of directions, depending on which direction you approach from.  Numbering both ramps as xx4 made directions simpler but was misleading.

I don't know if this is the case for the changes you cited, though.

 

[Phil]

Sounds like they have recalibrated their mile markers. 

Here is the current status of the recalibration of Utah highway markers.

http://www.udot.utah.gov/mileposts/progress_i15.html

The exit names have not changed, only the exit numbers.

 

[Ron]

Thanks for posting that Phil.  I didn't see any reason given for the changes.  Did they goof on the first go around?  Seems this is a expensive undertaking just to be doing to make work. ;D ;D  Would be interesting to know what prompted spending so much to change the exit numbers.

 

[Phil]

Thanks for posting that Phil.  I didn't see any reason given for the changes.  Did they goof on the first go around? 

Ron,

The construction on I-15 over the years has shortened the road by 4 miles.  The new markers match the road today. 

Phil

 

[Ron]

Sounds reasonable.  Thanks.

 

[Jim Godward]

Pat a& I noticed the difference between our spedometer and the MM some time ago on our yearly trek uup and down I-15 so am glad to see that I was not wrong!!  Sometimes I think I am but then...  VBG

I wonder why Pat put a sign over the door to my computer room as follows:

"Never but never question the Engineer's Judgement"  but then I got a pillow from her sister the same Christmas saying the same thing!  VBG

 

[blueblood]

Ron,

The construction on I-15 over the years has shortened the road by 4 miles.? The new markers match the road today.?

Phil

Because I-80 and I-15 shared the new construction in downtown SLC I suspected that was case but that  doesn't  explain I-70 or maybe Rt 89

 

[Ron]

Because I-80 and I-15 shared the new construction in downtown SLC I suspected that was case but that? doesn't? explain I-70 or maybe Rt 89

My BIL use to work for the UT State highway dept.  He mentioned once that there were a several places where MM/s with the same Nbr were installed a mile apart from each other.  When his crew reported this they were encourage to forget about it.  Wish I could remmember more details but CRS strikes again.  In any case this would probably be a good reason for changing things. ;D