This is the 3733rd most frequent Russian word.
федеральный
"Federal."
The word 'федеральное' is functioning as an adjective here, describing 'правительство' (government), emphasizing its national scope and level.
Федеральное правительство России состоит из различных министерств.
The federal government of Russia consists of various ministries.
In this context, 'федеральной' describes 'трассы' (highway), indicating its belonging to the nationwide infrastructure.
Эта дорога является частью федеральной трассы.
This road is part of a federal highway.
Here, 'федеральные' is used to describe 'законы' (laws), highlighting their authority and application at the national level.