This is the 2831st most frequent Russian word.
федеральной
"Federal."
In this sentence, 'федеральная' is an adjective describing the highway, indicating it is regulated or significant at a national level.
Федеральная трасса соединяет Москву и Санкт-Петербург.
The federal highway connects Moscow and Saint Petersburg.
Here, 'федеральная' describes the governmental nature of the service, emphasizing its role at the national level.
Федеральная служба проводит серьёзное расследование.
The federal service is conducting a serious investigation.
In this context, 'федеральной' is in its genitive case and modifies 'системы,' referring to the system's national scope.