NM: NM 606 needs truncation

[Jim]

I took NM 606 this morning from NM 122 to I-40 and was planning to take it the additional mile or so to the terminus we have in TM.  However, just past the EB ramps, the road becomes gravel, there's an "End State Maintenance" sign, followed by a county marker.  I'm happy to make this truncation but am putting it out there first in case there are any objections.

[oscar]

GMSV (2013) confirms that the part of NM 606 south of I-40 is not state-maintained, and now is signed as CR 28.

I'll take care of the truncation later this week, along with the NM 163 and HI changes.

EDIT: Pull request submitted for NM 163 and NM 606 changes.