SHAH ALAM - Gravity interaction and downhill roads may be the major causes of collisions involving heavy vehicles, says expert.
Referring to the crash that occurred in Putrajaya on Sept 20, National Defence University of Malaysia's (UPNM) Highway Engineering Specialist Professor Dr Ng Choy Peng said the convoy, which was headed downhill, made it difficult for heavy vehicles like trailers to make a stop.
Based on CCTV footage, Ng said the traffic police stopped the vehicles at a lower point as the road was going downhill and merging with another road.
"The place where they stop the vehicle is on a downhill road, so when we go downhill, especially with heavy vehicles like trailers, and moreover, if the breaking pads of the vehicle are not so good, it might not be able to stop on time.
"First thing first, if it was a flat road, then it shouldn't be a problem; unfortunately, the road is going downhill," she said to Sinar Daily.
Ng further pinpointed the driving path of the trailer, which initially drove in the middle lane before switching to the second lane.
She said it was difficult for the driver to stop because of the gravity interaction as the road was going downhill with the slope of the road.
"It is always advisable for heavy vehicles to drive in the left lane because that one is dedicated to heavy vehicles.
"However, in this case, since the road is going downhill, the trailer driver tried to avoid bumping into vehicles in front of him by changing lanes to the left side.
"But coincidentally, it is underneath a bridge, and there is no extra space on the road shoulder, so as it was going downhill, the trailer could not stop, and it crashed into other vehicles," she said.
When asked what kind of measures can be taken in the future to stop such incidents, Ng urged the authorities to pick safer locations during a police convoy.
"To stop accidents like this in the future, the authorities must be careful with the locations they pick to stop the vehicles.
"Gore areas where it merges two points of roads and downhill roads are extremely dangerous.
"If the road closures are done a bit further from these kinds of dangerous points, maybe we could avoid such accidents," she said.
A trailer ploughed into 11 vehicles, including a police escort motorcycle, claiming the lives of two motorcyclists at Kilometre 5.7 of Jalan Persiaran Utara in Putrajaya.
Putrajaya District Police Chief, Assistant Commissioner A Asmadi Abdul Aziz, said the incident occurred at around 10.14am when both victims, along with 11 other vehicles, stopped to give way to the traffic convoy of the Le Tour de Langkawi (LTdL), where the accident occurred.
He added that the police also arrested the driver of the trailer involved, which ploughed into 11 other vehicles.
It is also reported that one of the escort motorcycles also suffered severe damage, along with six cars, three motorcycles, and two trucks.