arc-en-ciel, that system is called: Runway Awareness and Advisory System (RAAS)
We have it in our little Cessna Citation Sovereign and when doing more than 40 knots on a taxiway, you get a real loud call "on taxiway, on taxiway".
I was just a software upgrade in our airplane (worth 23.000USD), apparently the EGPWS already has all required navdata to know when you´re not on a rwy...it uses the GPS actually. It also warns you when you approach a taxiway. (on approach)
SKYbrary - Runway Awareness and Advisory System (RAAS)
RAAS Certifications & Descriptions - EGPWS - Honeywell Aerospace