The North–South Expressway was constructed due to the congestion along the federal route 1 as a result of increasing traffic. In 1977, the government proposed to build a new north–south divided highway as an alternative to the federal route 1. The proposal to build the new highway was mooted as a result of the severe congestion along the Federal Route 1. Because of the large cost of the project, the highway was planned to be privatised and tolled, but none of the constructors being invited by the government were unwilling to do the job due to economic uncertainties at that time and the plan could not be materialised. It was only after Mahathir Mohamad became the Prime Minister that the North–South Expressway project was revived. The project was launched in 1981.