Images I found on the internet ...
FONTENOY-LE-COMPTE (Image INTERNET)(France)
CANNES (Image Internet)(France)
Stupid picture of a ceremony at CANNES, but if You look very closely You can see that behind the flag there is a VOIE SACREE marker ... believe it or not.
If You know about the whereabouts of similar markers, not on the VOIE SACREE itself, please coltact me ... email@example.com