Slow Down

Reduce our speed
Reported by Megawati Omar
Research Management Institute, UiTM
as automobiles industry expands, much has been debated about unnecessary casualties due to road accidents. At present the rate of road accident deaths in Malaysia hovers around 24 deaths per 100 000 people. Much deliberation and thoughts have taken place on how to reduce the rate of accidents, hence, Muhammad Akram Adnan and Mohd Jamaludin Md Noor of UiTM, Malaysia are studying to reduce the speed of vehicles, especially cars, as speed and road accidents casualties have a strong relationship.

They are to develop a geometric standard for effective and ‘friendly’ hump speed reducer that considers human factor. Humans are sometimes good in judging the impact of height but otherwise in the impact of speed. Worse, many ignore road safety and do not care about others even when driving within a school area. Other impacts of high speed on the road are air pollution, noise level and traffic safety.

Another nature of road accidents in Malaysia is that the number will rise in festival seasons thus attention is always focused on deaths on the road during the three festivals: Hari Raya, Chinese New year and Deevali. But in actual fact deaths and injuries occur all year round which include pedestrians. Investigation of road accidents show that when pedestrians are hit by cars at 30km/hr 5%, they will be killed, most injuries are slight and 30% suffer no injury, but those hit by cars at 50 km/hr, 45% killed and many seriously injured, and at 65 km/hr 85% killed.

In this case, according to Muhammad Akram Adnan and Mohd Jamaludin Md Noor, the speed reducer works by transferring an upward force to a vehicle, as it traverses. The force translates it into vertical displacement and acceleration. The displacement induces a front to back pitching motion to the vehicle occupants. As speed increases the amplitude, i.e. the vertical displacement, and pitching also increase. The magnitudes of displacement and acceleration are the measure for the uncomfortable sensation.

For vehicle speed of less than 70 km/h, this speed reducer is able to reduce speed less than the threshold value of 40 km/h, offer acceptable level of discomfort for vehicle occupants, avoid contact with vehicle base (thus no vehicle damage), and maximise overall road safety for road users.

Contact:

mohdjamaludin@salam.uitm.edu.my

Muhammad Akram Adnan
Mohd Jamaludin Md Noor
Malaysian Institute of Transport (MITRANS)
Faculty of Civil Engineering,
Universiti Teknologi MARA
40450 Shah Alam, Selangor, MALAYSIA