The motorcycle is a popular mode of transport in Malaysia and developing Asian countries, but its significant representation in the traffic mix results in high rates of motorcycle accidents. As a result, the Malaysian Government decided to segregate motorcycle traffic along its new federal roads as an engineering approach to reduce accidents. However, traffic engineers needed to know the maximum traffic a motorcycle lane could accommodate. Despite substantial literature related to speedÁflowÁdensity relationships and capacities of various transport facilities, there is a knowledge gap regarding motorcycle lanes. This paper establishes motorcycle speedÁflowÁdensity relationships and capacities of exclusive motorcycle lanes in Malaysia. Observations of motorcycle flows and speeds were conducted along existing and experimental motorcycle lanes. Motorcycle speedÁdensity data were aggregated and plotted for two types of observable motorcycle riding behaviour patterns that were influenced by the widths of a motorcycle lane: the headway pattern (lane width 5 1.7 m) and the space pattern (lane width ! 1.7 m). For both riding patterns, regression analysis of motorcycle speedÁdensity data best fits the logarithmic model and consequently the motorcycle flowÁdensity and speedÁflow models are derived. Motorcycle lane capacities for headway and space riding patterns are estimated as 3300 mc/hr/lane and 2200 mc/hr/m, respectively.

No abstract

This study aims to develop a road safety index that combines selected road environmental characteristics in Malaysia. Firstly, 14 indicators that generally portray the Malaysian road environments were selected. Then, the final list of specific indicators for each road network was developed. The indicators were derived based on the specific criteria such as the objectives, method of measurement, quality, and expected outcomes of the indicators that may improve the overall road safety of the Malaysian trunk roads. The Malaysian Federal Road 12 was selected as the study area to assess the applicability of the theory. By employing the principal component analysis, four components were obtained and from the statistical weightage of the indicator in each component, the composite indexes were calculated. The results showed that the sections with low number of reported crashes were not necessarily safe for road users. Instead, poor road environment conditions may be highly hazardous to road users. The presence of heavy vehicles and motorcycles was found to be the main risk factor of crash occurrences on this road. Overall, the crash data may be supplemented with another proactive method in order to get a broader picture of the poor road sections.

Abstract-In current road safety practices, the identification of hazardous road sections are normally based on crash data. However, the information provided by crash data may not be adequate to explain the causal factors that lead to a crash. Therefore, a different kind of road safety indicator that can extensively describe the actual road environment problems of a road section is considered essential. This paper considered fourteen road environment indicators based on their abilities to portray current road environment conditions and their potential towards road crash incidence. These indicators were collected using naturalistic driving technique within the 80-km road length connecting Kuantan and Maran town in the state of Pahang, Malaysia in which the composite road environment risk index was finally developed. This composite road environment risk index is found to be a useful proactive method to identify the potential problematic road sections that require urgent road improvement works as compared to the reactive crash data analysis method.Index Terms-Hazardous road sections, crash data, road environment, composite index, proactive method.

Aware on the importance of upgrading and maintaining the safety level of existing road network, several attempts on localizing problematic road areas have been made. In current practice, the identification of those problematic sections was recognized based on the road’s safety level and one of the most common and acceptable method is by using crash data of the particular road network as a starting point for further actions. However, the information provided by crash data is far from providing good and broad pictures of the factors leading to crash. These circumstances have bringing out the needs to have another road safety indicator that can extensively describes actual situations at problematic road areas as well as can be used as a basis for further maintenance works. By focusing on the environment aspect of the roads, fourteen road environment indicators were chosen based on their abilities to portrayed current road environment conditions and its potential in triggering road traffic crashes. Data of these indicators were collected by means of naturalistic driving method within 80 km length road of Federal Road 2 connecting Kuantan and Maran Town in Pahang State. Composite road environment risk index was developed using these data where combination of risk generated from these environments aspects were evaluated and used in localizing problematic road sections. Apart from that, the outcomes were also used as basis in planning for road improvement plans. The development of composite road environment risk index as a proactive method in defining poor sections has proved to be very useful in identifications of problematic road sections requiring urgent road improvement works especially when crash data is not available or in poor quality.