Speed is one of the important parameters of traffic flow that can be used to determine the perfor... more Speed is one of the important parameters of traffic flow that can be used to determine the performance of driver’s behaviour under various scenarios. Changes in weather conditions caused changes in drivers’ speed due to various reasons. In Malaysia, there is slightly high number of road accidents at night. Rainfall at night does not only cause poor visibility to drivers, but it also gives a sense of insecurity especially as there is a significant reduction in the visibility of the object in front. Improper road conditions can worsen the situation, for example, rainfall can cause water accumulation on road surfaces which can increase skidding problem, potholes and hydroplaning effect. In relation to these situations, hence it is crucial to understand how the abrupt situation affect response of driver’s in terms of the macroscopic behaviour. These unpredictable environmental changes seem like portraying a very unpleasant journey for drivers especially to travel under rainfall conditio...
Safe driving can be achieved by prevention of risky situations which requires the knowledge of th... more Safe driving can be achieved by prevention of risky situations which requires the knowledge of the vehicle dynamics and road geometry. The Indian traffic condition is heterogeneous in nature and has weak lane discipline. Hence, vehicles interactions takes place laterally also along with their longitudinal interaction. Vehicles lateral movements (interactions) are quite high due to absence of lane discipline. Therefore, the lateral acceleration of vehicles are an important variable which characterizes the corresponding vehicle dynamics. Several studies have been done by various authors on lateral acceleration in curves, however, lateral movement study of vehicles on straight road section is also important to analyze vehicles’ maneuver in such traffic (i.e. traffic stream with weak lane discipline). Therefore, the present study is about the observation of lateral movements of vehicles over different types of roads in three metropolitan cities of India (Kolkata, Mumbai and Pune) under ...
Composite traffic control mechanisms at intersections are normally made up of two or more traffic... more Composite traffic control mechanisms at intersections are normally made up of two or more traffic control devices; for example, roundabout and traffic signals combined or if you like, traffic signal and one way flow combined. Roundabouts work on the principle of circulation and entry flows; whereas signalised intersections rely on staging or phasing for effectiveness. Safety at roundabouts is enhanced by limiting circulating speeds and this is achieved in geometric design by entry path curvature. While control strategy of traffic signal is flexible; it hinges on vehicle actuation or fixed time operation. However, there are some vexing traffic safety issues worth considering at signalised roadways; for example, in the event of signal breakdown or malfunction, how would such intersections cope with gridlock; what are the delay trade-offs for installing a standard roundabout at existing signalised intersections or vice versa. As a consequence, delay studies were carried out at a signal...
In this paper, the author attempts to highlight a number of disaster related traffic management g... more In this paper, the author attempts to highlight a number of disaster related traffic management goals and objectives in a form of a guiding framework. The development of such a framework will serve as an effective decision making tool for a dynamic process of planning, design and implementation of traffic management in disasters. Such a framework will provide a decision support to traffic managers on how to operate a transport system in disasters. This framework would also help in the investigation and development of possible traffic management measures and strategies, which can be directly implemented during disasters.
Highway traffic theory is concerned with the movement of discrete objects in real time over a fin... more Highway traffic theory is concerned with the movement of discrete objects in real time over a finite network in 2 Dimensions. It is compatible with or dependent on fundamental diagram of traffic. Highway capacity is the apex point of the flow and density curve. The flow and density curve is asymmetric. It has 2 chambers (unconstrained and constrained). Obviously the constraint is capacity. The extent of highway capacity loss depends solely on the degree of traffic flowrate disturbances. Trapezoidal flowrate contraction is a description of the rate of flowrate forward movement within the constrained chamber of flow/density curve. A capacity estimation method was used that is based on extrapolation of the free flow part of the fundamental diagram representing flowrate and density in a 'with and without pavement distress' impact study in Skudai Malaysia. The method applied assumes that the density at capacity is not affected by road distress which implies that capacity losses are fully the result of speed changes. Capacities for two directions of one road section were estimated and compared. Results show that capacities for road section with good and distressed surfaces differ significantly and trapezoidal flowrate contraction ranges from 4m/s to 11m/s depending on the degree of capacity loss.
Researchers worldwide are engaged in the evaluation of the performance of urban travel modes. Eco... more Researchers worldwide are engaged in the evaluation of the performance of urban travel modes. Economic cost comparison studies are commonly used as instruments to substantiate the most favored mode in urban transport. This paper attempts to provide a comparison of current usage of city buses and cars in the Johor Bahru town of Malaysia. Technical costs, social costs and environmental costs are compared in ensuring accessibility and mobility on one hand and reducing accidents and environmental losses on the other. The study relates to a stretch of 14.5 km of 6-lane divided carriageway road connecting Pontian in the North and Johor Bahru, Malaysia, and Singapore in the South. Traffic data and Transport costs were obtained via primary and secondary sources. When car usage is involved, vehicle operating costs (VOC) was found to be three fold (RM 2.05/ person-km) than the VOC of bus usage (RM 0.7/ person-km). Similarly, social costs, which mainly included the cost of accidents, amounted to 80 times the accident cost associated with buses. Environmental costs were modeled based on speed and total vehicle volumes for CO, NOx, SOx, and PM10 emissions and were expressed as total investment in pollution control. The environmental costs were then calculated in terms of medical costs believed to be caused by the pollution. These pollution costs amounted to 15 times the pollution cost associated with buses. The total transport costs were then obtained to provide comparative evaluation of the study modes. Furthermore, multiple future scenarios were created to provide cost analyses over time periods and modal split cases. In this regard, this paper provided a framework for a cost evaluation approach for an urban area. Results indicated that city buses are more costeffective than cars, assuming equality in the number of passengers.
This paper deals with traffic impact assessment (TIA) of a proposed commercial development in the... more This paper deals with traffic impact assessment (TIA) of a proposed commercial development in the neighbourhoods of Skudai Town in the Johor Bahru region. We used three regimes: Trip Rate Analysis, Cross-Classification Analysis, and Regression Analysis to assess the future traffic expected to be caused by a developmenta proposed Tesco hypermarket (TH) in Skudai. The obtained mean trip rates were critically examined for forecasting traffic. The results indicated no significant variances from the estimated mean entry trip rates as mentioned in the Trip Generation Manual, Highway Planning Unit (HPU) of Malaysia. The estimated mean trip rates were used to measure the performance of a critical intersection in the immediate vicinity the development. The critical Intersection was analyzed using SIDRA software to estimate the delaya criterion for determining the level-of-service (LOS) provided to motorists. Traffic projections made for horizon year 2025 depicted a LOS 'F' with 2716.9s of average delay. Traffic improvements were also proposed to mitigate the impact of future development and traffic conditions. The study provided a framework for the estimation of trip rates for Malaysian conditions along with some guidelines for their adoption. These insights to TIA can assist developers or local authorities in decision making.
Traffic managers view disasters as events depicting sudden surge in traffic demand and deficient ... more Traffic managers view disasters as events depicting sudden surge in traffic demand and deficient transport supplies. In disasters, increments of transport capacities by transport-related development are impractical and traffic management measures are viable yet inexpensive options to mitigate the effects of disasters. This paper presents the methodology of qualitative assessment conducted on 27 pre-selected traffic management (TM) measures that are applicable to disasters. The methodology of the assessment includes: (i) estimation of relative weight of traffic management factors using analytic hierarchy process (AHP), (ii) self-assessment and rating of measures based on effectiveness and difficulty scales, (iii) determination of priority classes of measures based on qualitative assessment model, and (iv) the determination of residual measures signifying low applicability. Such an assessment aids decision-making process regarding the selection of measures and their applicability in t...
Trip Generation rates are important for transportation engineers and planners in the Travel Deman... more Trip Generation rates are important for transportation engineers and planners in the Travel Demand Forecasting process as well as for Traffic Impact Studies. Trip generation by a given land use type depends on one or more factors based on the socio-economic characteristics. The Institute of Transport Engineers (ITE) publishes and updates trip generation rates for different land use types at an interval of 2-3 years. In Malaysia, the Ministry of Public Works publishes trip generation information and the latest edition was published in 2010. Both of these documents recommend that the published trip rates be verified with local data, if possible. Different researches have been conducted in the developed countries but very rare in Malaysia. This study developed trip generation rates at fast-food restaurants in Johor Bahru, Malaysia. Ten fast-food locations were studied in detail. Trip rates were related to the number of parking spaces and gross floor area. However, the trip rates did n...
Short-haul public transport, particularly the passenger cars, is the most frequently utilized mod... more Short-haul public transport, particularly the passenger cars, is the most frequently utilized mode of transport in the world. Next to the private cars, taxis are the key to ensuring mobility in Oman where the state of development of public transport has been very slow. Despite having a high ratio of taxis to the private cars, the residents of Oman complain about the taxi services and their perception of taxi services in Oman is poor. Using a structured questionnaire targeted over a sample of 120 taxi drivers, this study reveals the basic statistics about taxis in Oman, their operations, the perspectives of taxi drivers and citizens about these services, the challenges to taxi business along with a few suggestions for improving taxi services in Oman. The study found that while taxis are the predominant mode of transportation in Oman, their operations are largely unorganized. Most of the taxi services are rendered on an individual basis. This paper also compared and contrasted the al...
Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research), 2014
About 80% of environmental performance is determined during product development. This study asses... more About 80% of environmental performance is determined during product development. This study assesses environmental impacts of wood-plastic composite (WPC) boards still in development, to identify impact hot spots and improvement potentials. A seven-step approach to ecodesign implementation was used. It identifies environmental impacts and derives improvement strategies. A life cycle assessment (LCA) according to ISO 14040 was conducted to quantify potential environmental impacts. The WPC boards are made of PVC and wood flour. Impacts mostly result from PVC and electricity consumption for production. Thus, this study proposes replacing PVC with polylactic acid (PLA). Further improvement strategies are increasing material efficiency, energy efficiency, renewable electricity use and secondary plastic input. Increased end of life recycling reduces environmental impacts, compared to incineration only. These changes reduce the initial climate change results of 145 kg CO 2 eq by 55%. Thus, early consideration of environmental aspects supports sustainable product development.
The urban transport systems are primarily the result of political decision-making processes, and ... more The urban transport systems are primarily the result of political decision-making processes, and only secondarily a matter of technical necessity or technical possibility, because every individual or group does have vested interests in transport policies, which are often conflicting if not inherently incompatible. What constitutes the so-called “common good” is not a technical question but ultimately a political one – while its implementation requires the suitable technical solution. This “comparative review of the making of urban transport policies in metropolitan areas of Singapore and Bangkok” analyses (1) the “input” of different actors into the political decision-making process, (2) how this input is processed by the various actors in government and administration, including the interaction of all participatory actors, and (3) finally how the results of these processes influence the form of the actual transport systems. The results are based on the research of the different pol...
Climate change is very likely to cause a sharp increase in temperature, which in turn is likely t... more Climate change is very likely to cause a sharp increase in temperature, which in turn is likely to affect atmospheric water storage, and thereby the magnitudes, frequencies and intensities of rainfall. The road environment, including the weather factors is one of the major causes of accident across the world. Therefore, it is very certain that climate change induced changes in weather factors will affect road safety, if proper adaptation measures are not taken. The major objective of this article is to review the existing literatures on the influence of climatic variables on road accident in order to assess the possible impacts of climate change on road safety in Malaysia. The analysis of exiting literatures reveals that most imminent and certain impacts of climate change on road safety will be due to increase of temperature and rainfall related extremes. However, the impacts may not be very high in Malaysia due to moderate changes of those extremes over a long time. Any potential r...
Public transport usage in Malaysia is showing a downward trend. Despite major improvements implem... more Public transport usage in Malaysia is showing a downward trend. Despite major improvements implemented as well as intended for public transport, the bus user satisfaction is constantly on a decline. This study investigated qualitative differences between bus users and operators based on 11 pre-selected quality attributes for an intercity travel in Malaysia with a predominant public transport mode– the Bus. The perceptions were measured via responses on a likert scale to establish differences. Perceptual, socio-economic and trip data were collected using questionnaire from bus users and operators on a pre-selected route-Johor Bahru to Kuala Lumpur (JB-KL). Analyses used statistical tools particularly correlation analyses, step-wise multiple regression analyses, Mann Whitney test methods and Wilcoxon test. Quadrant analyses established relationship between relative importance and satisfaction from quality attributes. Results indicate significant correlation differences in both groups ...
Speed is one of the important parameters of traffic flow that can be used to determine the perfor... more Speed is one of the important parameters of traffic flow that can be used to determine the performance of driver’s behaviour under various scenarios. Changes in weather conditions caused changes in drivers’ speed due to various reasons. In Malaysia, there is slightly high number of road accidents at night. Rainfall at night does not only cause poor visibility to drivers, but it also gives a sense of insecurity especially as there is a significant reduction in the visibility of the object in front. Improper road conditions can worsen the situation, for example, rainfall can cause water accumulation on road surfaces which can increase skidding problem, potholes and hydroplaning effect. In relation to these situations, hence it is crucial to understand how the abrupt situation affect response of driver’s in terms of the macroscopic behaviour. These unpredictable environmental changes seem like portraying a very unpleasant journey for drivers especially to travel under rainfall conditio...
Safe driving can be achieved by prevention of risky situations which requires the knowledge of th... more Safe driving can be achieved by prevention of risky situations which requires the knowledge of the vehicle dynamics and road geometry. The Indian traffic condition is heterogeneous in nature and has weak lane discipline. Hence, vehicles interactions takes place laterally also along with their longitudinal interaction. Vehicles lateral movements (interactions) are quite high due to absence of lane discipline. Therefore, the lateral acceleration of vehicles are an important variable which characterizes the corresponding vehicle dynamics. Several studies have been done by various authors on lateral acceleration in curves, however, lateral movement study of vehicles on straight road section is also important to analyze vehicles’ maneuver in such traffic (i.e. traffic stream with weak lane discipline). Therefore, the present study is about the observation of lateral movements of vehicles over different types of roads in three metropolitan cities of India (Kolkata, Mumbai and Pune) under ...
Composite traffic control mechanisms at intersections are normally made up of two or more traffic... more Composite traffic control mechanisms at intersections are normally made up of two or more traffic control devices; for example, roundabout and traffic signals combined or if you like, traffic signal and one way flow combined. Roundabouts work on the principle of circulation and entry flows; whereas signalised intersections rely on staging or phasing for effectiveness. Safety at roundabouts is enhanced by limiting circulating speeds and this is achieved in geometric design by entry path curvature. While control strategy of traffic signal is flexible; it hinges on vehicle actuation or fixed time operation. However, there are some vexing traffic safety issues worth considering at signalised roadways; for example, in the event of signal breakdown or malfunction, how would such intersections cope with gridlock; what are the delay trade-offs for installing a standard roundabout at existing signalised intersections or vice versa. As a consequence, delay studies were carried out at a signal...
In this paper, the author attempts to highlight a number of disaster related traffic management g... more In this paper, the author attempts to highlight a number of disaster related traffic management goals and objectives in a form of a guiding framework. The development of such a framework will serve as an effective decision making tool for a dynamic process of planning, design and implementation of traffic management in disasters. Such a framework will provide a decision support to traffic managers on how to operate a transport system in disasters. This framework would also help in the investigation and development of possible traffic management measures and strategies, which can be directly implemented during disasters.
Highway traffic theory is concerned with the movement of discrete objects in real time over a fin... more Highway traffic theory is concerned with the movement of discrete objects in real time over a finite network in 2 Dimensions. It is compatible with or dependent on fundamental diagram of traffic. Highway capacity is the apex point of the flow and density curve. The flow and density curve is asymmetric. It has 2 chambers (unconstrained and constrained). Obviously the constraint is capacity. The extent of highway capacity loss depends solely on the degree of traffic flowrate disturbances. Trapezoidal flowrate contraction is a description of the rate of flowrate forward movement within the constrained chamber of flow/density curve. A capacity estimation method was used that is based on extrapolation of the free flow part of the fundamental diagram representing flowrate and density in a 'with and without pavement distress' impact study in Skudai Malaysia. The method applied assumes that the density at capacity is not affected by road distress which implies that capacity losses are fully the result of speed changes. Capacities for two directions of one road section were estimated and compared. Results show that capacities for road section with good and distressed surfaces differ significantly and trapezoidal flowrate contraction ranges from 4m/s to 11m/s depending on the degree of capacity loss.
Researchers worldwide are engaged in the evaluation of the performance of urban travel modes. Eco... more Researchers worldwide are engaged in the evaluation of the performance of urban travel modes. Economic cost comparison studies are commonly used as instruments to substantiate the most favored mode in urban transport. This paper attempts to provide a comparison of current usage of city buses and cars in the Johor Bahru town of Malaysia. Technical costs, social costs and environmental costs are compared in ensuring accessibility and mobility on one hand and reducing accidents and environmental losses on the other. The study relates to a stretch of 14.5 km of 6-lane divided carriageway road connecting Pontian in the North and Johor Bahru, Malaysia, and Singapore in the South. Traffic data and Transport costs were obtained via primary and secondary sources. When car usage is involved, vehicle operating costs (VOC) was found to be three fold (RM 2.05/ person-km) than the VOC of bus usage (RM 0.7/ person-km). Similarly, social costs, which mainly included the cost of accidents, amounted to 80 times the accident cost associated with buses. Environmental costs were modeled based on speed and total vehicle volumes for CO, NOx, SOx, and PM10 emissions and were expressed as total investment in pollution control. The environmental costs were then calculated in terms of medical costs believed to be caused by the pollution. These pollution costs amounted to 15 times the pollution cost associated with buses. The total transport costs were then obtained to provide comparative evaluation of the study modes. Furthermore, multiple future scenarios were created to provide cost analyses over time periods and modal split cases. In this regard, this paper provided a framework for a cost evaluation approach for an urban area. Results indicated that city buses are more costeffective than cars, assuming equality in the number of passengers.
This paper deals with traffic impact assessment (TIA) of a proposed commercial development in the... more This paper deals with traffic impact assessment (TIA) of a proposed commercial development in the neighbourhoods of Skudai Town in the Johor Bahru region. We used three regimes: Trip Rate Analysis, Cross-Classification Analysis, and Regression Analysis to assess the future traffic expected to be caused by a developmenta proposed Tesco hypermarket (TH) in Skudai. The obtained mean trip rates were critically examined for forecasting traffic. The results indicated no significant variances from the estimated mean entry trip rates as mentioned in the Trip Generation Manual, Highway Planning Unit (HPU) of Malaysia. The estimated mean trip rates were used to measure the performance of a critical intersection in the immediate vicinity the development. The critical Intersection was analyzed using SIDRA software to estimate the delaya criterion for determining the level-of-service (LOS) provided to motorists. Traffic projections made for horizon year 2025 depicted a LOS 'F' with 2716.9s of average delay. Traffic improvements were also proposed to mitigate the impact of future development and traffic conditions. The study provided a framework for the estimation of trip rates for Malaysian conditions along with some guidelines for their adoption. These insights to TIA can assist developers or local authorities in decision making.
Traffic managers view disasters as events depicting sudden surge in traffic demand and deficient ... more Traffic managers view disasters as events depicting sudden surge in traffic demand and deficient transport supplies. In disasters, increments of transport capacities by transport-related development are impractical and traffic management measures are viable yet inexpensive options to mitigate the effects of disasters. This paper presents the methodology of qualitative assessment conducted on 27 pre-selected traffic management (TM) measures that are applicable to disasters. The methodology of the assessment includes: (i) estimation of relative weight of traffic management factors using analytic hierarchy process (AHP), (ii) self-assessment and rating of measures based on effectiveness and difficulty scales, (iii) determination of priority classes of measures based on qualitative assessment model, and (iv) the determination of residual measures signifying low applicability. Such an assessment aids decision-making process regarding the selection of measures and their applicability in t...
Trip Generation rates are important for transportation engineers and planners in the Travel Deman... more Trip Generation rates are important for transportation engineers and planners in the Travel Demand Forecasting process as well as for Traffic Impact Studies. Trip generation by a given land use type depends on one or more factors based on the socio-economic characteristics. The Institute of Transport Engineers (ITE) publishes and updates trip generation rates for different land use types at an interval of 2-3 years. In Malaysia, the Ministry of Public Works publishes trip generation information and the latest edition was published in 2010. Both of these documents recommend that the published trip rates be verified with local data, if possible. Different researches have been conducted in the developed countries but very rare in Malaysia. This study developed trip generation rates at fast-food restaurants in Johor Bahru, Malaysia. Ten fast-food locations were studied in detail. Trip rates were related to the number of parking spaces and gross floor area. However, the trip rates did n...
Short-haul public transport, particularly the passenger cars, is the most frequently utilized mod... more Short-haul public transport, particularly the passenger cars, is the most frequently utilized mode of transport in the world. Next to the private cars, taxis are the key to ensuring mobility in Oman where the state of development of public transport has been very slow. Despite having a high ratio of taxis to the private cars, the residents of Oman complain about the taxi services and their perception of taxi services in Oman is poor. Using a structured questionnaire targeted over a sample of 120 taxi drivers, this study reveals the basic statistics about taxis in Oman, their operations, the perspectives of taxi drivers and citizens about these services, the challenges to taxi business along with a few suggestions for improving taxi services in Oman. The study found that while taxis are the predominant mode of transportation in Oman, their operations are largely unorganized. Most of the taxi services are rendered on an individual basis. This paper also compared and contrasted the al...
Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research), 2014
About 80% of environmental performance is determined during product development. This study asses... more About 80% of environmental performance is determined during product development. This study assesses environmental impacts of wood-plastic composite (WPC) boards still in development, to identify impact hot spots and improvement potentials. A seven-step approach to ecodesign implementation was used. It identifies environmental impacts and derives improvement strategies. A life cycle assessment (LCA) according to ISO 14040 was conducted to quantify potential environmental impacts. The WPC boards are made of PVC and wood flour. Impacts mostly result from PVC and electricity consumption for production. Thus, this study proposes replacing PVC with polylactic acid (PLA). Further improvement strategies are increasing material efficiency, energy efficiency, renewable electricity use and secondary plastic input. Increased end of life recycling reduces environmental impacts, compared to incineration only. These changes reduce the initial climate change results of 145 kg CO 2 eq by 55%. Thus, early consideration of environmental aspects supports sustainable product development.
The urban transport systems are primarily the result of political decision-making processes, and ... more The urban transport systems are primarily the result of political decision-making processes, and only secondarily a matter of technical necessity or technical possibility, because every individual or group does have vested interests in transport policies, which are often conflicting if not inherently incompatible. What constitutes the so-called “common good” is not a technical question but ultimately a political one – while its implementation requires the suitable technical solution. This “comparative review of the making of urban transport policies in metropolitan areas of Singapore and Bangkok” analyses (1) the “input” of different actors into the political decision-making process, (2) how this input is processed by the various actors in government and administration, including the interaction of all participatory actors, and (3) finally how the results of these processes influence the form of the actual transport systems. The results are based on the research of the different pol...
Climate change is very likely to cause a sharp increase in temperature, which in turn is likely t... more Climate change is very likely to cause a sharp increase in temperature, which in turn is likely to affect atmospheric water storage, and thereby the magnitudes, frequencies and intensities of rainfall. The road environment, including the weather factors is one of the major causes of accident across the world. Therefore, it is very certain that climate change induced changes in weather factors will affect road safety, if proper adaptation measures are not taken. The major objective of this article is to review the existing literatures on the influence of climatic variables on road accident in order to assess the possible impacts of climate change on road safety in Malaysia. The analysis of exiting literatures reveals that most imminent and certain impacts of climate change on road safety will be due to increase of temperature and rainfall related extremes. However, the impacts may not be very high in Malaysia due to moderate changes of those extremes over a long time. Any potential r...
Public transport usage in Malaysia is showing a downward trend. Despite major improvements implem... more Public transport usage in Malaysia is showing a downward trend. Despite major improvements implemented as well as intended for public transport, the bus user satisfaction is constantly on a decline. This study investigated qualitative differences between bus users and operators based on 11 pre-selected quality attributes for an intercity travel in Malaysia with a predominant public transport mode– the Bus. The perceptions were measured via responses on a likert scale to establish differences. Perceptual, socio-economic and trip data were collected using questionnaire from bus users and operators on a pre-selected route-Johor Bahru to Kuala Lumpur (JB-KL). Analyses used statistical tools particularly correlation analyses, step-wise multiple regression analyses, Mann Whitney test methods and Wilcoxon test. Quadrant analyses established relationship between relative importance and satisfaction from quality attributes. Results indicate significant correlation differences in both groups ...
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Papers by Anil Minhans