Warm Mix Asphalt (WMA) represents the technologies that allow the reducing of asphalt binders’ mixing and compaction temperatures by reducing its binders’ viscosity. This paper gives a comprehensive chronological review from prior researches and practical experienced among researchers and industrial practitioners while implementing WMA technology including constituent materials, mix design and mechanical performance issues. Within this, the problems and benefits as well as different types of WMA additives were clearly identified as essential for a better understanding of the application of WMA technology in pavement constructions.

The fatal accidents on the roads remain a global concern. Daily, approximately 18 traffic accidents occur in the Peninsular Malaysia that cause on an average one death in every hour, a situation that needs preventive measures. The development of the effective strategies to reduce such fatal accidents requires the identification of various risk factors including the road condition. We identified such accident severity issues using the public work and police department databases that consisted of 1067 cases of various severity levels occurred on the Malaysian federal roads during 2008 to 2015. These records were used to develop ordered logistic regression model for the accident severity and nine variables were analyzed. The results revealed that the presence of poor horizontal alignment affected the model outcomes. The likelihood of the more serious accident severity due to the poor horizontal alignment was correspondingly about 0.4 times less compared to the absence of such factors. It is established that the present findings may assist the local authorities to take proactive actions to prevent serious road accidents on the road segments possessing the standard horizontal alignment.

This paper explores the impact of various rainfall conditions on traffic flow and speed at selected location in Terengganu and Johor using data collected on two-lane highway. The study aims to quantify the effect of rainfall on average volume, capacity, mean speed, free-flow speed and speed at capacity. This study is important to come out with recommendation for managing traffic under rainfall condition. Traffic data were generated using automatic traffic counters for about three months during the monsoon season. Rainfall data were obtained from nearest surface rain gauge station. Detailed vehicular information logged by the counters were retrieved and processed into dry and various rainfall conditions. Only daylight traffic data have been used in this paper. The effect of rain on traffic flow and speed for each condition were then analysed separately and compared. The results indicated that average volumes shows no pronounce effect under rainfall condition compared to those under dry condition. Other parameters, however, show a decrease under rainfall condition. Capacity dropped by 2-32%, mean speed, free-flow speed and speed at capacity reduced by 3-14%, 1-14% and 3-17%, respectively. The paper recommends that findings from the study can be incorporated with variable message sign, local radio and television, and variable speed limit sign which should help traffic management to provide safer and more proactive driving experiences to the road user. The paper concluded that rainfall irrespective of their intensities have impact on traffic flow and speed except average volume.

Accidents are a never ending issue and have been in the rise for the past decades. It has been a significant contributor towards death of human which is alarming yearly with the increase of road users and also with the large construction of road pavement around the globe. This paper is intended to provide an overview regarding the rate of accident and pavement conditions. Human factors has been widely known and established as one of the main contributor to road accidents. This study therefore will be focusing more on to pavement conditions, where its relation with accidents needs to be further explored. Macrotexture, microtexture and surface roughness plays an important role in providing an acceptable and ideal pavement condition. Higher friction between the tire and pavement should be established in order to resist skid and rutting effects. In order to solve problems related to accidents, the causes of accidents has to be further analyzed. A review on pavement conditions and accidents will be discussed further in this paper.

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Overtaking is one of many important behaviour considered in the analysis of road traffic accidents and performance of single carriageway road. This paper seeks to determine factors affecting the speed of an overtaking vehicle. The study was conducted for a single carriageway road section which is flat and straight so that there is no effect of sight distance on overtaking. Overtaking behaviour data were recorded using a video camera. The data extracted from the video recordings were the decision times, overtaking times, overtaking distances, safety margins, accepted and rejected gaps, headways at the start of the overtaking manoeuvres, headways at the end of the overtaking manoeuvres, speed of the overtaken vehicle, speed of the overtaking vehicle at the end of the overtaking and acceleration of the overtaking vehicle during the overtaking. The data were analysed statistically to establish relationships between the various overtaking parameters. This study found that the speed of overtaking vehicle was affected by the speed of overtaken vehicle, drivers’ decision times, safety margin, overtaking times and acceleration.

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