The MUTCD requires overhead signs with "EXIT ONLY" panels for all lane drops on freeways and expressways (Section 2E.24). So why do some freeway lane drops go for significant periods of time without this kind of overhead signage?
A local example that comes to mind is southbound US 69 in Overland Park, Kansas, in advance of the 135th Street exit. For a long time, the lane drop was not even signed
at all, but the city and/or the state finally did something to address it. They used post-mounted signs with a black-on-yellow "RIGHT LANE ONLY" panel for the 135th Street exit guide signs. One of these was even replaced recently with a nearly identical sign, and a new one was added. The exit direction sign lacked any lane drop indication until recently, when the "RIGHT LANE ONLY" panel was added to that one, too. This is an example of the style of signage I am referring to:
https://goo.gl/maps/f4XBtMdHgmuI've also noticed two major areas in Texas where the #3 and/or #4 lanes were dropped without the MUTCD-prescribed type of signage: EB I-10 around TX Loop 375 on the east side of El Paso, and NB US 75 around McKinney.
Is there a good reason for doing this (aside from saving money on signs)? Are these DOTs experimenting with new types of lane drop signage for later addition to the MUTCD? What do other people think about freeway lane drops that lack the MUTCD-prescribed signage?