It was reported that the travelling time from Serendah to Selayang via the Kuala Lumpur–Ipoh Road FT1 may take up to 2 hours due to severe congestion in Rawang town centre.

[5] Along the FT37 highway, only two interchanges exist, with about three stub LILO intersections and a fast lane-to-fast lane U-turn near its northern terminus for southbound traffic.

[5] The project was initially supposed to be constructed as a controlled-access expressway that would run along the Federal Route 1 corridor, with LeKLAS Sdn.

[1] However, the Rawang Bypass project was constructed not as a controlled-access toll expressway but rather as a limited-access divided highway.

[5] The second stage was to build a completely new bypass route that diverts the through traffic away from the town centre of Rawang.

[5] Due to protests from environmentalists and pressure from local residents who insisted on going ahead with the project despite possible environmental issues, the route was realigned and redesigned, and a 2.7-km viaduct was constructed along the border of the Selangor State Heritage Park to minimize the negative impact towards the critically endangered Giam Kanching trees which is an endemic species and can only be found nowhere else but in the heritage park.