Cornering Stability Analysis of Double Decker Bus at KM15 of Cameroon Highlands – Simpang Pulai Road

Double decker buses are widely used on Malaysian road today because of its
ability to increase the profits for the coach operatorsthrough the reduction of fuel
consumption and its operating maintenance cost as well as the ability to carry more
passengers per trip compared to single deck buses. Because of the popularity of using
double decker buses for a long distance travel is keep increasing, it has become a
major concern in road safety since many fatal accidents happened involving this type
of vehicle. On 20th December 2010, Malaysia was shocked by news of the horrific
accident that resulted 27 passengers killed out of 37 passengers at KM15 Cameroon
Highlands- SimpangPulai road. This is the worst historical road accident in the
nation's history. The accident started after the vehicle hit a divider and overturned on
its way down from Cameron Highlands. It landed on its roof in a ditch about 51m
away from the divider. The bus was heading to Kuala Lumpur from Cameron
Highlands. The Malaysian Institute of Road Safety (Miros) has found double decker
buses to be not suitable for long distance travel especially on winding, mountainous
regions with steep slopes roads like in Sabah, Sarawak and Cameroon Highlands as
they have high centre of gravity. There are many possibilities of the factor to happen.
To get the confirmation of the exact factor of the accident, an analysis is carry out at
the place where the accident is happened. Method used in the analysis is by visiting
the site, calculation of the slip and tip angle and speed of the vehicle, modelling and
simulation of double decker bus using Adams Car software.