The Bicycling Coalition of NM and the Los Alamos County Transportation Board have both been critical of the NMDOT and DOE/LANL past practice of partial shoulder paving, i.e., putting the final layer of new pavement only onto the travel lanes and often ending it halfway onto the road shoulder where it forms a lip or edge. This technique, used rarely in the U.S., may save a few bucks but often makes the shoulder impassible or hazardous to cyclists and motorcyclists because the lip can disrupt steering. Good examples of this technique can be found all across NM-4 in the Jemez Mountains, where the lip at times becomes a veritable cliff, and on some parts of Truck Route. Riders on NM4 in the Jemez, for example, have no choice but to use the travel lane whether they want to or not.
Thankfully, it seems that the folks now in charge of roadway maintenance at LANL have stopped using this technique. The new pavement being installed on W. Jemez and Pajarito Road goes edge to edge, leaving a safe, smooth, fast shoulder to bicycle on.
As others have said on the pajarito-riders bike list, "Thank You!" to LANL/DOE for thinking of all of us!