Prime Minister Najib Abdul Razak has pledged to improve public transportation, which has been ignored for decades.

As a result of this, Najib said, there is debilitating traffic not only in the Klang Valley, but also in the other cities.

"The choking effect of traffic congestion makes any city less ideal to live in and this will be less attractive to visitors and investors," he added.

Najib said the government has been taking decisive action to remedy the shortcomings in the public transportation area.

"Rest assured, as PM, I will continue to give full attention to the modernisation of the public transport infrastructure," he added in his speech at the ground breaking ceremony for the Sungai Buloh-Serdang-Putrajaya (SSP) MRT line in Putrajaya today.

Meanwhile, Minister in the Prime Minister's Department Abdul Rahman Dahlan said the MRT construction should have been started during the protracted tenure of Malaysia's fourth prime minister, Dr Mahathir Mohamad.

"Public transport like the MRT is a need for a capital city like Kuala Lumpur, which is known for being developed.

"It is a symbol of development. This is why it is important for us to develop the MRT and LRT systems now.

"It should have been done 20 years ago, but there were several reasons it could not. So we are doing it now," Rahman told reporters after the event.

This is the second phase of the SSP MRT Line project, and involves the construction of a 52.2 kilometre track.

The SSP Line will have 37 stations, of which 11 will be underground. It will go from Sungai Buloh to Putrajaya through Kepong, Kampung Batu, Jalan Ipoh, Titiwangsa, KLCC, Tun Razak Exchange, Bandar Malaysia, Sungai Besi, Serdang and Cyberjaya.

The first phase of the SSP MRT Line project, from Sungai Buloh and Kampung Batu, is expected to be operational in 2021, while the entire line will be operational in the second half of 2022.

This MRT system expects a daily capacity of 529,000 passengers.