An assessment of the effects of road humps on traffic speed and noise in the residential areas

Abstract

The installation of road humps in residential areas have calmed residential roads as they seem to have reduced the traffic speed along these roads. However, at drawback of road humps installation is that they cause nuisance due to the noise and vibration produced by the sudden acceleration and deceleration of vehicles. This study evaluates the effects of road humps on traffic speed and noise level in residential areas. The study was conducted for two different sets of road humps in Taman Setiawangsa and Keramat and measurement of the road humps and road profiles were done for each road. The speed of each vehicle and noise levels at selected points were measured by using a radar gun and noise level meters. The sample size for spot speed was determined by using a systematic sampling technique based on the collected 12-hour traffic volume survey done earlier. Satisfaction and perceptions of residents on traffic speed and noise were conducted through face to face interviews with randomly selected residents by using simple random sampling. Data were analysed using descriptive statistics, which described the changes in vehicles speed and noise levels along the selected roads, as well as taking into account the patterns of speed and noise levels. The differences in mean for both speed and noise levels were analysed by using T-test while correlation analysis was used to analyse the relationship between speed and noise level. As for the questionnaire data, descriptive analysis was applied to identify the residents’ demographic and socioeconomic background while cross tabulation analysis was used to evaluate the perceptions and satisfaction of the residents. As expected, the results of the speed survey showed that the highest speed recorded was along Jalan Keramat with 28.75 km/h and the lowest was Jalan Setiawangsa 21, 14.35 km/h. Meanwhile, the highest noise level, 72.36 dB was recorded along Jalan Keramat and the lowest, 57.88 dB was recorded along Jalan Setiawangsa 21, affected by road humps characteristics, particularly height and width of the humps, have influenced the speed produced by the vehicles. This showed the significant relationship between traffic speed and noise and verified that the increase in speed resulted in high noise levels. It was found that the relationship between traffic speed and noise level was significant as the noise level was affected by the accelerating and decelerating vehicles, apart from being influenced by the road and hump profiles as well as the types of vehicles involved. The findings on significant changes showed that road humps were effective in reducing speed, but the results on traffic noise produced was on the contrary. As for the questionnaire survey results, most residents were satisfied that road humps functioned well in reducing traffic speed compared to traffic noise. The residents also expressed their dissatisfaction towards traffic speed and noise in their residential areas. However, this study only assessed the effects of road humps on traffic speed and noise levels in residential areas, by comparing different roads and road hump profiles. Further study can be done by considering other factors such as traffic volume. The expected findings can be a basis in solving issues on traffic speed and noise in residential areas including the execution of road humps in new residential developments.