It runs between the town of Gombak in Selangor to the southwest and Karak in Pahang to the northeast.

The expressway was previously a single-carriageway trunk road forming part of federal route 2; this designation has been kept after the upgrade in 1997.

The expressway begins at Gombak, Selangor and its interchange with the Kuala Lumpur Middle Ring Road 2.

However, the cost of the construction of this highway was considered as expensive for Malaysia which at that time was an agricultural country.

Therefore, the government decided to make Kuala Lumpur–Karak Highway as a toll road to help cover all the construction works.

The upgrading works also included the construction of a second tunnel located beside the existing tunnel to provide additional two lanes for eastbound traffic, widening the toll gates at Gombak and Bentong and also constructing interchanges to replace junctions.