More could have been done to help motorists familiarise themselves with the new road network when the Marina Coastal Expressway (MCE) opened, said Transport Minister Lui Tuck Yew in Parliament on Monday.

A combination of factors, including motorists driving more carefully and not taking the most appropriate routes, had contributed to traffic congestion on the morning of Dec 30, he said.

Dec 30 was the first working day after the MCE opened, and jams along the $4.3 billion expressway and surrounding roads to the Marina financial district left motorists stuck for up to two hours.

Mr Lui said in retrospect, publicity could have been stepped up closer to the MCE opening date of Dec 29. More signs could also have been provided to give motorists earlier guidance, he added.

Apart from that morning, peak hour traffic along the MCE tunnel and adjoining roads have been generally smooth though traffic volumes have returned to prior levels before the December holidays, he said.

He added that speeds along the MCE and the downgraded East Coast Parkway (ECP) are now generally faster than on the old ECP, exceeding the threshold of 65kmh at some points in the morning and evening.

That prompted Holland-Bukit Timah GRC MP Liang Eng Hwa to ask if electronic road pricing (ERP) charges at that location would be reviewed. ERP rates go as high as $6 along some gantries near the city.

In response, Mr Lui said the Land Transport Authority is currently reviewing ERP charges for the coming quarter, and will announce the results in due course.

Turning to the MCE's design, Mr Lui said: "Some observers had concluded in the immediate aftermath of the jam that first working day morning that there was a design flaw with the MCE. I think that was a premature conclusion. If indeed there had been a design flaw, we would likely have seen congestion not only that particular morning but in a number of mornings to follow and perhaps in the evening as well."