Don’t underestimate dangers of trams, experts warn after fatal accident in Hong Kong
- Weighing up to 28 tonnes, trams take longer distance to stop than cars, they say
Hong Kong’s trams may pose a greater safety risk to pedestrians than cars as they underestimate the longer stopping distances required during emergencies, experts have said.
The girl was crossing the street with her six-year-old sister, their grandfather, 66, and the family’s domestic helper, 34, all of whom were also injured.
The family were believed to be crossing the street while the red signal was on, according to a source familiar with the case. The three injured were in a stable condition.
Police said they had arrested the driver, 48, for dangerous driving causing death and detained him for inquiries.
Lo Kok-keung, a retired engineer from Polytechnic University, warned that pedestrians should not underestimate the risks of trams. They were heavier and required greater stopping distances in emergencies, said Lo, who often appears in court as an expert witness.
“As opposed to private cars or taxis which weigh about 1.4 tonnes, trams can weigh up to 27 to 28 tonnes. The force can be massive,” he said.
He explained that a tram travelling at 10km/h (6.2mph) could require 0.9 seconds to come to a complete stop after covering an additional 1.3 metres (4.2 feet) upon braking. If it hit a pedestrian, the tram could potentially trap the victim beneath it due to the extra distance.
“When trams are approaching, don’t cross the tracks as they can’t stop immediately as they brake,” he said.
Lo also noted that the differences in friction are significant, as trams used metal wheels on metal tracks, whereas cars had rubber tires on concrete roads.
A higher coefficient of friction – measuring the resistance between two surfaces – results in quicker stops. He said that for wheels on roads, the coefficient was approximately 0.7, while for trams, it ranged from 0.1 to 0.3.
Yeh Yung-sheng, chairman of the Hong Kong Tramway Workers Union, warned that pedestrians should always be cautious around tracks.
He said that trams typically operated at below 40km/h. An alarm is installed to alert drivers to slow down as they approach this limit.
“Tram drivers are also required to attend annual training sessions with a test afterwards that includes fault recovery and emergency braking,” he said, without commenting specifically on the case.
While police did not disclose the speed of the tram at the time of the accident, Yeh said they could investigate using a black box-like system installed on trams.
District councillor Timothy Lau Tin-ching noted the accident occurred in an area that was not typically considered a traffic black spot, emphasising it was a wide road with five lanes.
He added that vehicles travelling in the opposite direction of the eastward tram might have made crossing more challenging, and that morning rain could have obscured visibility for both the driver and pedestrians.
There have been several fatalities in connection with trams in recent years. On January 31, a 37-year-old woman was hit by a tram on Des Voeux Road Central in Central and died in hospital two days later.
In July last year, a 42-year-old man died after being knocked down and run over by a tram in Sheung Wan.
In January 2018, a 79-year-old female visitor from mainland China suffered head injuries after being hit by a tram in Causeway Bay. She was conscious and sent to hospital for treatment.
In November 2002, a 72-year-old woman died after falling under a tram in front of her husband, who was also thrown into a tram stop and suffered minor injuries in Western.
Additional reporting by William Yiu
