Human factor has been identified as the main cause of accidents involving heavy vehicles such as lorries and buses on the North-South Expressway.

According to PLUS regional manager Mohamad Pazli Kasim, a total of 9,059 accidents with 353 fatalities were recorded last year.

He said of out this figure, 1,690 accidents involved lorries while another 218 involved buses.

"According to our records, 83 per cent of accidents involving heavy vehicles last year were due to human factor involving the attitude and habits of the drivers themselves.

"This was followed by mechanical factor or vehicle problems, at 14 per cent, and environmental factor at three per cent," he told reporters at the 'Respect Your Limits' seminar, here, Tuesday.

He said driving despite feeling sleepy or tired and poorly maintaining their vehicles in order to do as many trips and to make as much money were the main causes of accidents involving lorries and buses.

Mohamad Pazli said from January to April this year, a total of 3,091 accidents were recorded with 128 fatalities, including 48 involving lorries and eight involving buses.

Meanwhile, Peninsular Malaysia Bus Drivers Association chairman Sa'adan Man said a small basic salary and no additional allowance had driven some bus drivers to do as many trips as possible in order to earn more.

He said not all bus operators in the country provided the drivers with basic salary, so the latter had to depend on the trips they made to earn income.

"I hope the government can consider providing a cost of living allowance to bus drivers," he said.