Hong Kong experts say cushions can fix flawed flyover dividers

Officials see no need for better crash barriers even as experts say recent accident shows that sloped ramps can send vehicles flying

PUBLISHED : Tuesday, 25 September, 2012, 12:00am
UPDATED : Tuesday, 25 September, 2012, 3:52am

No action is being taken to improve the safety of about 15 ramped central dividers on flyovers despite a fatal crash this month in which a taxi ran up a ramp, took off and plunged into a park below.

The transport and highways departments said the design of all central dividers - which separate traffic lanes that go in the same direction to minimise accidents - complied with established practices and guidelines. They have no plans to add new safety measures at this time.

However, Lo Kok-keung, from Polytechnic University's department of mechanical engineering, and road safety consultant Julian Kwong Tse-hin said the structures' design was outdated and posed risks to drivers.

Lo said the sloping central divider on the Ngau Tau Kok flyover, in particular, where the crash happened on September 9, had acted as a launching ramp.

"It sent the taxi into the air before the cab dived into a gap between two diverging roads," the engineer said.

The cab plunged about 10 metres down and landed on its roof, trapping 55-year-old driver Wong Siu-kong inside. He was declared dead at the scene.

A police officer said it was believed that prior to the crash, the driver realised he was in the wrong lane and tried to switch to another one. The officer said there was no sign that the car exceeded the 50km/h speed limit.

After three people died in a similar crash on the Tsing Ma Bridge in December 1998, cushion barriers made of metal were installed at the ends of 15 dividers on roads where the speed limit was 70km/h or higher.

At another 15 locations with a speed limit of 50km/h or below, reflective traffic bollards were installed in front of the dividers to alert drivers.

Both Lo and Kwong called for crash cushions - designed to absorb the impact of a colliding vehicle to slow it down - on all dividers.

Lo said the Ngau Tau Kok crash showed that even a vehicle travelling at 50km/h could fly off a road if it ran up such a "launching board".

"It is a matter of life and death, so new safety facilities are necessary. Safety always comes first," Lo said.

Kwong agreed, saying the dividers could cause vehicles to flip, and warned of more casualties if a public bus were to crash.

After inspecting the Ngau Tau Kok site, however, officials said the design of the dividers was "appropriate and a crash cushion was not considered necessary".

A spokeswoman said the Highways Department had been conducting regular reviews and inspections.

"Enhancement to the ramped concrete dividers at specific locations in the territory is considered on an individual basis and will be arranged whenever necessary," she said.