This is the 2235th most frequent Russian word.
дорожные
"Дорожные" means "road" or "travel" (adjective, e.g., relating to roads or travel).
The word 'дорожные' here modifies 'знаки' (signs), indicating that these signs are related to roads.
Дорожные знаки помогают водителям ориентироваться на местности.
Road signs help drivers navigate in the area.
'Дорожных' describes 'покрытий' (surfaces), specifying that these surfaces are part of the road infrastructure.
Городская администрация планирует ремонт дорожных покрытий.
The city administration plans to repair road surfaces.
'Дорожной' defines 'обочины' (roadside), signifying the connection to the road.