Please always indicate if the route has a suffix, e.g. N-IIa. Thanks.
Ok, I'll do it from now! Here's N-III (no N-IIIa, or suffixes, don't worry)
1 - The first remaining stretch of N-III I've found
starts at this roundabout in Arganda del Rey (wrongly colored, there's also a sign pointing backwards, but there's no signage in the previous streets, so I assume the parts before have been all transferred), after partly bypassing the town, exits it, then interchanges with A-3 (exits 33, 33A and 33B), crosses with M-220 and A-3 exit 35, contiunes towards Perales del Tajuña and ends in the roundabout (here's a sign of it:
https://goo.gl/maps/7RcVGYZHf1z) with M-204 and A-3 exit 41.
2 - This section starts at
A-3 exit 79, and though not signed, there is
a kilometer sign some meters later. After bypassing Tarancón and crossing with N-400 (shares denomination with it for some meters), then interchanges with N-400 (ending the sharing), passes under the A-3 connecting with its exit 85, to finally merge with it
here. Here's
a kilometer sign a bit before the merging
3 - This stretch, which starts at
A-3 exit 93, crosses Villarrubio and ends
in exit 95, only has
this sign remaining (note the decolored by the years N-III numbering in the top part, this sign is so old it even uses the French font Caractères!)
4 - There's another stretch in Saelices from exit 101 to a stub, though as there's no signage it cannot be part of Travel Mapping. I'm posting it anyway just for any curious roadgeek reading this, as this stretch bypasses an old N-III section with the original cobblestone pavement of the CNFE (first network of roads in Spain suitable for cars), dating back to the 1920s. This historical section starts
here. Also, in the whole section you can see intersting stuff like ancient signage and even yellow markings in the road center (like in the US) sometimes, as the roads in Spain were yellow marked for separating lanes back in the 50's.
5 - This part starts at
A-3 exit 114, crosses Montalbo and ends in exit 117. This section also has very interesting old signage, like
this (that's supposed to be a gas pump!), but what matters is that it's actually part of the N-III, as
this kilometer sign shows (sorry for the angle, plants obstruct the view).
6 - This stretch starts at exit 130 (here a
kilometer sign just after it), crosses Villares del Saz (
here's the road number above the village name) and ends
in exit 133.
7 - This long section going through the beautiful reservoir of Contreras, and which I've had the luck to clinch partially starts at
A-3 exit 165, passes through Honrubia, goes over Alarcón Dam, crosses Motilla del Palancar, where crosses with CM-220, gives access to Castillejo de Iniesta, Graja de Iniesta and Minglanilla, to interchange with CM-211 and arrives to Contreras mountain pass, where it gets very scenic. After going through a tunnel (and linking with CV-4661 before, that goes where the N-III used to go before the building of the Contreras Dam and it's a quite beautiful mountain drive), and other one, goes over the Contreras Dam, which also separes Castile-La Mancha and the Land of Valencia. Another tunnel awaits us (now in the Valencian side); leaves the mountain area to pass under the A-3 for giving access to Villagordo del Cabriel, where it crosses with CV-474; after that, it goes over the AVE high speed railway, goes through Caudete de las Fuentes and Utiel, where crosses with N-330, CV-392 and A-3 exit 278, then with exit 281, passing under it. After that, it links with exit 285, later it crosses San Antonio, then it bypasses Requena (which also has a very nice cobblestone part) and finally merges into the A-3
in exit 291.
8 - N-III returns
in this roundabout, linking it to exit 306, goes under and then over the A-3 to serve some housing developments, then enters Buñol and continues as a service road for the motorway for a while to finally merge near exit 322.
Here's a sign in the other way next to Buñol just to be sure.
9 - This stretch starts
at this roundabout (
a milestone some meters later tells us this is N-III), bypasses Chiva and ends
in a stub made by the motorway.
Thanks for your work!