Improved engineering specification design for road hump : a case study on residential streets in Shah Alam / Nor Izzah Zainuddin

Speed hump or also known as road hump is designed to ensure safety for both drivers
and pedestrian. The use of speed humps in residential streets is an efficient way of
controlling speed ofvehicles. However, in Malaysia some ofthe dimensions designed
by the local authorities had been implemented on an 'ad hoc' basis without any proper
standards or guidelines (HPU, 2002). Although Highway Planning Unit (HPU) and
Standards and Industrial Research Institute of Malaysia (SIRIM) have stipulated
specific ranges of dimensions for the installation of speed humps, however no perfect
and ideal guidelines were introduced and were not properly enforced by the local
authorities. Therefore, with many styles and inconsistent designs of the speed humps a
well-established empirical study has been implemented to develop optimal designs
consistency models. In this study, the geometric design of the speed hump was related
to 85th percentile speed and discomfort level. The speed data were carried out by using
a laser gun meter detector to obtain the spot speed data at the selected speed hump
location and vibration data collection were carried out using triaxial acceleration
transducers connected to Racelogic VBOX II SX. Multiple linear regression analysis
was conducted to develop a statistical relationship between speed hump geometric,
85th percentile speed and discomfort level. In the validation stage, the site empirical
data were compared with the predicted data using the paired T -test and discrepancy
measure such as Root Mean Squared Error (RMSE), Mean Absolute Error (MAE),
and Mean Absolute Percentage Error (MAPE). Finally, the models have successfully
developed and validated according to the statistical procedures in the study. The
findings are hoped to provide a starting point towards the development of a standard
for the speed humps in residential areas which will not only focus on the effectiveness
but also considering the safety and discomfort level of the road users while travelling
on the speed hump.