The Federal Route 1 is the first federal road in Malaysia, and also the oldest federal road in Malaysia, as well as among the nation's earliest public roadways ever constructed. The Federal Route 1 became the backbone of the road system in the western states of Malaysia before being surpassed by the North-South Expressway (E1 and E2).
The Federal Route 1 is one of the three north-south backbone federal highways in Peninsular Malaysia; the other two are the Federal Routes 3 and 5.
The Kilometre Zero of the Federal Route 1 is located at the Malaysia-Singapore border at the Johor-Singapore Causeway. Since 2008, it is no longer possible to access the Causeway by the Federal Route 1, when the new Sultan Iskandar CIQ Complex was opened with access to the border checkpoint provided by the Johor Bahru Eastern Dispersal Link Expressway.
At the first kilometre at the city of Johor Bahru, it is connected with the Federal Route 3, the main trunk road of the east coast of Peninsular Malaysia. Next, at Kilometre 19 which is at Skudai, the route is connected with the Federal Route 5 which is the main trunk road of the west coast of Peninsular Malaysia.
The Federal Route 1 is the main trunk road at the interior part of Peninsular Malaysia but passes the western states. From Tampin to Sungai Siput, the FT1 highway runs along the western foothills of the Titiwangsa Range. The FT1 highway intersects with the Federal Route 2 at Kuala Lumpur before intersecting with another end of the Federal Route 5 at Ipoh. At Sungai Siput, Perak, the route changes its direction westbound and later become the main west coastal route, starting from Changkat Jering, Perak to Alor Setar, Kedah. The route meets with the North-South Expressway Northern Route E1 at Jitra, Kedah and the section of the North-South Expressway from Jitra to Bukit Kayu Hitam is a part of the Federal Route 1.