This is the 11534th most frequent French word.
routières
"Routières" means "related to roads or road transport."
In this sentence, 'routières' is used as an adjective describing 'cartes' (maps), meaning they are related to roads.
Les cartes routières sont essentielles pour les voyages en voiture.
Road maps are essential for car trips.
Here, 'routières' acts as an adjective describing 'autorités' (authorities), indicating they are concerned with roads.
Les autorités routières planifient de nouvelles infrastructures pour améliorer le trafic.
The road authorities are planning new infrastructures to improve traffic.
In this example, 'routières' is an adjective modifying 'signalétiques' (signage), referring to signage pertaining to roads.