This is the 4137th most frequent Portuguese word.
rodoviárias
"Rodoviárias" means "bus stations" or "related to highways."
In this sentence, 'rodoviários' refers to bus terminals by attributing the concept of 'rodoviário' (related to roads or buses) to 'terminais' (terminals).
Os terminais rodoviários estão sempre movimentados.
The bus terminals are always busy.
Here, 'rodoviárias' directly refers to bus stations, used as a noun to name these places.
As condições das rodoviárias precisam de melhorias.
The conditions of the bus stations need improvement.
In this usage, 'rodoviárias' describes companies related to road or bus transportation, functioning as an adjective to the noun 'empresas' (companies).