Region with the most systems would be a French one- fraa
- eure
- fran
- several M/D systems
- possibly eursf and/or eurtr
I'm going to go with Auverge-Rhone-Alpes as the winner.
ARA (Warning: Don't open the link) has 24 systems but I have not yet drafted 4 M route systems lacking signposting.
eure - UNECE International 'E' Roads - 1038.63 miles
eursf - Europe Select Named Freeways - 29.75 miles
eurtr - Europe Select Tourist and Scenic Routes - 207.88 miles
fraa - France Autoroutes - 1034.53 miles
fraarad01 - Ain Routes Départementales - 2565.53 miles
fraarad03 - Allier Routes Départementales - 3106.29 miles
fraarad07 - Ardèche Routes Départementales - 1826.77 miles
fraarad15 - Cantal Routes Départementales - 2146.56 miles
fraarad26 - Drôme Routes Départementales - 2248.69 miles
fraarad38 - Isère Routes Départementales - 2769.04 miles
fraarad42 - Loire Routes Départementales - 2027.01 miles
fraarad43 - Haute-Loire Routes Départementales - 1841.87 miles
fraarad63 - Puy-de-Dôme Routes Départementales - 3858.08 miles
fraarad69 - Rhône Routes Départementales - 1475.17 miles
fraarad73 - Savoie Routes Départementales - 1542.18 miles
fraarad74 - Haute-Savoie Routes Départementales - 1508.75 miles
frabfcd58 - Nièvre Routes Départementales - 1.06 miles
frabfcd71 - Saône-et-Loire Routes Départementales - 0.45 miles
fracvld18 - Cher Routes Départementales - 2.11 miles
fran - France Routes Nationales - 636.86 miles
fraoccd12 - Aveyron Routes Départementales - 0.82 miles
fraoccd46 - Lot Routes Départementales - 2.04 miles
fraoccd48 - Lozère Routes Départementales - 2.36 miles
frapacd05 - Hautes-Alpes Routes Départementales - 0.97 miles