Pretty amazing, actually because most of the signs on 287 north of Exit 14 were installed between 1993-97. The only real replacements were right around Exit 41 for Rt 80 which are much newer but suffering from terrible UV fading on the interstate shields. Signs from 13 down to the Turnpike were pretty much all installed in 1998 (except for the Exit 8 signs which were from around 1994). I've felt like they've held up fine for the most part. NJDOT has done very few replacements over the years, save for signs that got mauled in accidents (except, it seems, for the ground mounts approaching Exit 10 going SB, which have been knocked over multiple times over the years and just put back up) and a couple of overhead structures they needed to replace. I expect that we'll get at least one new sign for Exit 10 NB since the old one was bridge mounted to the River Rd overpass and was taken down. I wonder if a broader signage project is going to eventually be in the works for 287 given that at the northern end of the roadway, most of those signs are rapidly approaching 30 years of age.
The Middlesex and Somerset Counties had diagram signs for decades that only in 1985 got repainted. Yes they were repainted! They were given reflecting green from the old style green used on button copies. Other than that NJDOT kept them.
The SB guide though for CR 527 in Somerset was never replaced with a new diagramical sign when it got knocked down in the very early eighties. They used two small guides that were in upper case lettering instead of replacing the guides with another large diagram sign or large standard sign.
Plus in the early eighties only River Road, CR 527, and Weston Canal Road received exit numbers south of US 22 then but the rest did not get them though US 202 and 206 in Bedminster and Bridgewater got them.
However on another subject at least I-287 was the only one in north Central Jersey to use square county Route shields instead of street names back in the sixties. I-78 used road names east of I-287 like Martinsville Road for CR 525 and Hilcrest Road for CR 531. Then at CR 523 just Oldwick and Whitehouse were signed and even CR 525 on I-287 was signed solely as Mount Airy Road.
Also I never understood why Stelton Road never had been built with a complete interchange from the start. It was only made complete in either the early or mid nineties. Plus why was South Washington Avenue signed as SB CR 529 from I-287 NB before the current sign installed in Piscataway is another mystery and why no SB I-287 ramp from NB Washington still missing.