Modelling,predicting and analysing driver behaviours are essential to advanced driver assistance systems(ADAS)and the comprehensive understanding of complex driving scenarios.Recently,with the development of deep lear...Modelling,predicting and analysing driver behaviours are essential to advanced driver assistance systems(ADAS)and the comprehensive understanding of complex driving scenarios.Recently,with the development of deep learning(DL),numerous driver behaviour learning(DBL)methods have been proposed and applied in connected vehicles(CV)and intelligent transportation systems(ITS).This study provides a review of DBL,which mainly focuses on typical applications in CV and ITS.First,a comprehensive review of the state-of-the-art DBL is presented.Next,Given the constantly changing nature of real driving scenarios,most existing learning-based models may suffer from the so-called“catastrophic forgetting,”which refers to their inability to perform well in previously learned scenarios after acquiring new ones.As a solution to the aforementioned issue,this paper presents a framework for continual driver behaviour learning(CDBL)by leveraging continual learning technology.The proposed CDBL framework is demonstrated to outperform existing methods in behaviour prediction through a case study.Finally,future works,potential challenges and emerging trends in this area are highlighted.展开更多
Driver steering intention prediction provides an augmented solution to the design of an onboard collaboration mechanism between human driver and intelligent vehicle.In this study,a multi-task sequential learning frame...Driver steering intention prediction provides an augmented solution to the design of an onboard collaboration mechanism between human driver and intelligent vehicle.In this study,a multi-task sequential learning framework is developed to pre-dict future steering torques and steering postures based on upper limb neuromuscular electromyography signals.The joint representation learning for driving postures and steering intention provides an in-depth understanding and accurate modelling of driving steering behaviours.Regarding different testing scenarios,two driving modes,namely,both-hand and single-right-hand modes,are studied.For each driving mode,three different driving postures are further evaluated.Next,a multi-task time-series transformer network(MTS-Trans)is developed to predict the future steering torques and driving postures based on the multi-variate sequential input and the self-attention mechanism.To evaluate the multi-task learning performance and information-sharing characteristics within the network,four distinct two-branch network architectures are evaluated.Empirical validation is conducted through a driving simulator-based experiment,encompassing 21 participants.The pro-posed model achieves accurate prediction results on future steering torque prediction as well as driving posture recognition for both two-hand and single-hand driving modes.These findings hold significant promise for the advancement of driver steering assistance systems,fostering mutual comprehension and synergy between human drivers and intelligent vehicles.展开更多
Driver management may be considered an organization’s most valuable asset, and State-Owned Enterprises (SOEs) must invest in it to secure their survival and growth. The study sought to establish the effect of driver ...Driver management may be considered an organization’s most valuable asset, and State-Owned Enterprises (SOEs) must invest in it to secure their survival and growth. The study sought to establish the effect of driver management on service delivery in SOEs. Various empirical studies reveal that there is a lack of understanding of the impact of driver management on service delivery in public organizations, notably SOEs, resulting in sectorial and contextual research gaps that must be filled. The study used a mixed-method research strategy and a pragmatic research philosophy. In addition, 344 respondents from 86 SOEs were given standardized questionnaires to complete. The researchers employed stratified and purposive sampling. Statistical package for social scientists (SPSS) version 20 was used to generate descriptive statistics. All study items were subjected to exploratory factor analysis (EFA), and research hypotheses were assessed using Structural Equation Modelling (SEM) in AMOS version 21. The study findings revealed that despite having clear driver recruiting procedures, there is bad driver conduct and a lack of driver recognition programs to reward good driving. The study concluded that driver management has a positive effect on service delivery. In light of these conclusions, the study suggests that SOEs should ensure that drivers understand their responsibilities when using company vehicles. Furthermore, drivers should be periodically trained in line with the tenets of the New Public Management Theory which advocates for quality service delivery, customer centrism and reduction in rigidity.展开更多
As the overall population ages, driving-related accidents and injuries, associated with elderly drivers, have risen. Existing research about elderly drivers mainly focuses on factual data collection and analysis, indi...As the overall population ages, driving-related accidents and injuries, associated with elderly drivers, have risen. Existing research about elderly drivers mainly focuses on factual data collection and analysis, indicating the elderly's growing fatal accident rates and their different behaviours compared to younger drivers. However, few research has focused on design-led practical solutions to mitigate the elderly's growing fatal accidents, by consid- ering their usability and body conditions, afflicting the elderly, such as decreased vision, hearing, and reaction times. In this paper, first, current worldwide situations on growing fatal accident rates for elderly drivers is reviewed and the key impact factors are identified and discussed with regarding to usability and design trend in the automotive technology for elderly. Second, existing smart vehicle technology-based solutions to promote safe driving are explored and their pros and cons are discussed and anal- ysed. Most of solutions are not created by people with driving difficulties, which are caused by health problems most commonly afflicting the elderly. Thirdly, diverse design-led research activities are taken, such as a survey, observation, and interviews to gain new understanding of what kinds of driving problems elderly drivers have and demonstrate how new system concepts could be developed for the elderly's benefits. Finally, it is found that the elderly's low vision and late reaction are main factors causing their driving difficulties. Based on this finding, usable vehicle system design ideas have been proposed, by utilising facial expression sensing technology as a solution. The proposed solutions would ensure reducing both the elderly's driving problems and high fatal accident rates and provide a more enjoyable driving environment for the elderly population.展开更多
One of the main factors affecting the safety of signalised intersections is the stop/go behaviour during the yellow interval.Although previous research has exhaustively examined drivers’stop/go decision-making,the ex...One of the main factors affecting the safety of signalised intersections is the stop/go behaviour during the yellow interval.Although previous research has exhaustively examined drivers’stop/go decision-making,the expected autonomous vehicles’(AVs’)stop/go behaviour has not yet been thoroughly investigated.Through a series of simulation experiments developed for conventional and autonomous vehicles using different carfollowing,lane-changing,lateral placement and stop/go model parameter values,we examine here whether the default VISSIM stop/go parameter values can adequately replicate the observed drivers’behaviour at the considered intersection and assess the suitability of using the currently available options,albeit referring to human drivers,to simulate the expected stop/go behaviour of AVs.We also propose a policy framework for determining the desired behaviour of AVs in yellow interval,which is integrated into an AVs logic and achieved in the last simulation to explore the effect of automation on the stop/go outcome and,hence,on the safety level of signalised intersections.Several data analysis and modeling techniques were used for the formulation of certain scenarios,including binary choice models.The default stop/go parameter values were found unfit to replicate the observed stop/go behaviour and subjected to calibration.Compared to the currently available options,the proposed AVs logic proved to produce the most accurate results,in terms of the stop/go simulation outcome.Regarding the impact of automation on the stop/go outcome,the simulation experiments showed that AVs preferred a more conservative behaviour in favor of road safety,as indicated by the significant reduction(≈15%)in the number of vehicles crossing the stop line during the yellow light and zero instances of red light violation.However,compared to the conservative drivers represented by the default stop/go parameter values,AVs preferred a more rational behaviour in favor of intersection capacity without compromising road safety.展开更多
Sight obstructions along road curves can lead to a crash if the driver is not able to stop the vehicle in time.This is a particular issue along curves with limited available sight,where speed management is necessary t...Sight obstructions along road curves can lead to a crash if the driver is not able to stop the vehicle in time.This is a particular issue along curves with limited available sight,where speed management is necessary to avoid unsafe situations(e.g.,driving off the road or invading the other traffic lane).To solve this issue,we proposed a novel intelligent speed adaptation(ISA)system for visibility,called V-ISA(intelligent speed adaptation for visibility).It estimates the real-time safe speed limits based on the prevailing sight conditions.V-ISA comes with three variants with specific feedback modalities(1)visual and(2)auditory information,and(3)direct intervention to assume control over the vehicle speed.Here,we investigated the efficiency of each of the three V-ISA variants on driving speed choice and lateral behavioural response along road curves with limited and unsafe available sight distances,using a driving simulator.We also considered curve road geometry(curve direction:rightward vs.leftward).Sixty active drivers were recruited for the study.While half of them(experimental group)tested the three V-ISA variants(and a V-ISA off condition),the other half always drove with the V-ISA off(validation group).We used a linear mixed-effect model to evaluate the influence of V-ISA on driver behaviour.All V-ISA variants were efficient at reducing speeds at entrance points,with no discernible negative impact on driver lateral behaviour.On rightward curves,the V-ISA intervening variant appeared to be the most effective at adapting to sight limitations.Results of the current study implies that V-ISA might assist drivers to adjust their operating speed as per prevailing sight conditions and,consequently,establishes safer driving conditions.展开更多
A shared control of highly automated Steer-by-Wire system is proposed for cooperative driving between the driver and vehicle in the face of driver's abnormal driving. A fault detection scheme is designed to detect...A shared control of highly automated Steer-by-Wire system is proposed for cooperative driving between the driver and vehicle in the face of driver's abnormal driving. A fault detection scheme is designed to detect the abnormal driving behaviour and transfer the control of the car to the automatic system designed based on a fault tolerant model predictive control(MPC) controller driving the vehicle along an optimal safe path.The proposed concept and control algorithm are tested in a number of scenarios representing intersection, lane change and different types of driver's abnormal behaviour. The simulation results show the feasibility and effectiveness of the proposed method.展开更多
Improper lane-changing behaviours may result in breakdown of traffic flow and the occurrence of various types of collisions.This study investigates lane-changing behaviours of multiple vehicles and the stimulative eff...Improper lane-changing behaviours may result in breakdown of traffic flow and the occurrence of various types of collisions.This study investigates lane-changing behaviours of multiple vehicles and the stimulative effect on following drivers in a consecutive lanechanging scenario.The microscopic trajectory data from the HighD dataset are used for driving behaviour analysis.Two discretionary lane-changing vehicle groups constitute a consecutive lane-changing scenario,and not only distance-and speed-related factors but also driving behaviours are taken into account to examine the impacts on the utility of following lane-changing vehicles.A random parameters logit model is developed to capture the driver’s psychological heterogeneity in the consecutive lane-changing situation.Furthermore,a lane-changing utility prediction model is established based on three supervised learning algorithms to detect the improper lane-changing decision.Results indicate that 1)the consecutive lane-changing behaviours have a significant negative effect on the following lane-changing vehicles after lane change;2)the stimulative effect exists in a consecutive lane-change situation and its influence is heterogeneous due to different psychological activities of drivers;and 3)the utility prediction model can be used to detect an improper lane-changing decision.展开更多
We propose a model structure with a double-layer hidden Markov model (HMM) to recognise driving intention and predict driving behaviour. The upper-layer multi-dimensional discrete HMM (MDHMM) in the double-layer HMM r...We propose a model structure with a double-layer hidden Markov model (HMM) to recognise driving intention and predict driving behaviour. The upper-layer multi-dimensional discrete HMM (MDHMM) in the double-layer HMM represents driving intention in a combined working case, constructed according to the driving behaviours in certain single working cases in the lower-layer multi-dimensional Gaussian HMM (MGHMM). The driving behaviours are recognised by manoeuvring the signals of the driver and vehicle state information, and the recognised results are sent to the upper-layer HMM to recognise driving intentions. Also, driving behaviours in the near future are predicted using the likelihood-maximum method. A real-time driving simulator test on the combined working cases showed that the double-layer HMM can recognise driving intention and predict driving behaviour accurately and efficiently. As a result, the model provides the basis for pre-warning and intervention of danger and improving comfort performance.展开更多
There has been an increase in the number of on-road vehicles of all types,especially in some developing countries.The rise of traffic heterogeneity causes larger mixed traffic conge stion.This study examines the impac...There has been an increase in the number of on-road vehicles of all types,especially in some developing countries.The rise of traffic heterogeneity causes larger mixed traffic conge stion.This study examines the impact of next-nearest leading vehicles on the driving of following drivers in mixed traffic.Although previous studies reported that traffic stability can be improved with the introduction of followers’anticipatory driving that refers to multiple leaders,the effect of anticipatory driving on mixed traffic has not yet been examined.Using data collected from experiments conducted with groups of two and three vehicles,we found that operational delay,maximum acceleration and deceleration of the followers were affected by the presence of next-nearest leaders.In addition,we developed regression models of the affected followers’behaviours with respect to the next-nearest leaders and identified the factors affecting these behaviours.For example,the followers’deceleration is directly affected by the height of the next-nearest leading vehicles.Hence,the model parameters for determining the deceleration of following vehicles should take the height of the next-nearest leading vehicle into consideration.Finally,based on the regression models,we estimated values of parameters in the intelligent driver model when the type of the next-nearest leader was changed.Stability analysis based on these estimated parameters implied that a tall or short next-nearest leader with a large engine power would stabilise traffic when anticipatory driving of followers is possible.展开更多
The ownership of motorised two wheelers(MTWs)has been on the rise across various countries across the globe.The growth has been especially higher in developing countries which have typical traffic characteristics and ...The ownership of motorised two wheelers(MTWs)has been on the rise across various countries across the globe.The growth has been especially higher in developing countries which have typical traffic characteristics and higher populations.This steady rise has resulted in increased accident and fatalities.This abrupt increase warranted attention from the researchers to carry out specific studies for MTWs,which have a very different behaviour as compared to cars in terms of physical and dynamic parameters.Moreover,the unique traffic patterns usually found in the developing countries pose an additional challenge to the researchers,since the conventional focus of transportation safety researchers was a homogeneous car-based traffic.Many such studies have been attempted,especially in the recent decades,which have considered various risk factors related to MTW safety.However,the studies have considered different sets of risk factors and have given surprising and even conflicting results.Therefore,a comprehensive review of the diverse studies needs to be carried out which incorporates all the risk factors considered in previous research.This study reviews such research papers which have analysed various risk factors related to safety of MTWs,especially in heterogeneous,non-lane based traffic.Specifically,this paper aims to incorporate results from those studies and highlight the conclusions from state of the art.The paper also discusses about the research gaps that are crucial for MTW safety in mixed traffic conditions.The review will be useful for researchers working in the field of MTW safety and for policy implementation and analysis.展开更多
基金Supported by the National Key Research and Development Program of China(No.2022ZD0115503).
文摘Modelling,predicting and analysing driver behaviours are essential to advanced driver assistance systems(ADAS)and the comprehensive understanding of complex driving scenarios.Recently,with the development of deep learning(DL),numerous driver behaviour learning(DBL)methods have been proposed and applied in connected vehicles(CV)and intelligent transportation systems(ITS).This study provides a review of DBL,which mainly focuses on typical applications in CV and ITS.First,a comprehensive review of the state-of-the-art DBL is presented.Next,Given the constantly changing nature of real driving scenarios,most existing learning-based models may suffer from the so-called“catastrophic forgetting,”which refers to their inability to perform well in previously learned scenarios after acquiring new ones.As a solution to the aforementioned issue,this paper presents a framework for continual driver behaviour learning(CDBL)by leveraging continual learning technology.The proposed CDBL framework is demonstrated to outperform existing methods in behaviour prediction through a case study.Finally,future works,potential challenges and emerging trends in this area are highlighted.
文摘Driver steering intention prediction provides an augmented solution to the design of an onboard collaboration mechanism between human driver and intelligent vehicle.In this study,a multi-task sequential learning framework is developed to pre-dict future steering torques and steering postures based on upper limb neuromuscular electromyography signals.The joint representation learning for driving postures and steering intention provides an in-depth understanding and accurate modelling of driving steering behaviours.Regarding different testing scenarios,two driving modes,namely,both-hand and single-right-hand modes,are studied.For each driving mode,three different driving postures are further evaluated.Next,a multi-task time-series transformer network(MTS-Trans)is developed to predict the future steering torques and driving postures based on the multi-variate sequential input and the self-attention mechanism.To evaluate the multi-task learning performance and information-sharing characteristics within the network,four distinct two-branch network architectures are evaluated.Empirical validation is conducted through a driving simulator-based experiment,encompassing 21 participants.The pro-posed model achieves accurate prediction results on future steering torque prediction as well as driving posture recognition for both two-hand and single-hand driving modes.These findings hold significant promise for the advancement of driver steering assistance systems,fostering mutual comprehension and synergy between human drivers and intelligent vehicles.
文摘Driver management may be considered an organization’s most valuable asset, and State-Owned Enterprises (SOEs) must invest in it to secure their survival and growth. The study sought to establish the effect of driver management on service delivery in SOEs. Various empirical studies reveal that there is a lack of understanding of the impact of driver management on service delivery in public organizations, notably SOEs, resulting in sectorial and contextual research gaps that must be filled. The study used a mixed-method research strategy and a pragmatic research philosophy. In addition, 344 respondents from 86 SOEs were given standardized questionnaires to complete. The researchers employed stratified and purposive sampling. Statistical package for social scientists (SPSS) version 20 was used to generate descriptive statistics. All study items were subjected to exploratory factor analysis (EFA), and research hypotheses were assessed using Structural Equation Modelling (SEM) in AMOS version 21. The study findings revealed that despite having clear driver recruiting procedures, there is bad driver conduct and a lack of driver recognition programs to reward good driving. The study concluded that driver management has a positive effect on service delivery. In light of these conclusions, the study suggests that SOEs should ensure that drivers understand their responsibilities when using company vehicles. Furthermore, drivers should be periodically trained in line with the tenets of the New Public Management Theory which advocates for quality service delivery, customer centrism and reduction in rigidity.
文摘As the overall population ages, driving-related accidents and injuries, associated with elderly drivers, have risen. Existing research about elderly drivers mainly focuses on factual data collection and analysis, indicating the elderly's growing fatal accident rates and their different behaviours compared to younger drivers. However, few research has focused on design-led practical solutions to mitigate the elderly's growing fatal accidents, by consid- ering their usability and body conditions, afflicting the elderly, such as decreased vision, hearing, and reaction times. In this paper, first, current worldwide situations on growing fatal accident rates for elderly drivers is reviewed and the key impact factors are identified and discussed with regarding to usability and design trend in the automotive technology for elderly. Second, existing smart vehicle technology-based solutions to promote safe driving are explored and their pros and cons are discussed and anal- ysed. Most of solutions are not created by people with driving difficulties, which are caused by health problems most commonly afflicting the elderly. Thirdly, diverse design-led research activities are taken, such as a survey, observation, and interviews to gain new understanding of what kinds of driving problems elderly drivers have and demonstrate how new system concepts could be developed for the elderly's benefits. Finally, it is found that the elderly's low vision and late reaction are main factors causing their driving difficulties. Based on this finding, usable vehicle system design ideas have been proposed, by utilising facial expression sensing technology as a solution. The proposed solutions would ensure reducing both the elderly's driving problems and high fatal accident rates and provide a more enjoyable driving environment for the elderly population.
文摘One of the main factors affecting the safety of signalised intersections is the stop/go behaviour during the yellow interval.Although previous research has exhaustively examined drivers’stop/go decision-making,the expected autonomous vehicles’(AVs’)stop/go behaviour has not yet been thoroughly investigated.Through a series of simulation experiments developed for conventional and autonomous vehicles using different carfollowing,lane-changing,lateral placement and stop/go model parameter values,we examine here whether the default VISSIM stop/go parameter values can adequately replicate the observed drivers’behaviour at the considered intersection and assess the suitability of using the currently available options,albeit referring to human drivers,to simulate the expected stop/go behaviour of AVs.We also propose a policy framework for determining the desired behaviour of AVs in yellow interval,which is integrated into an AVs logic and achieved in the last simulation to explore the effect of automation on the stop/go outcome and,hence,on the safety level of signalised intersections.Several data analysis and modeling techniques were used for the formulation of certain scenarios,including binary choice models.The default stop/go parameter values were found unfit to replicate the observed stop/go behaviour and subjected to calibration.Compared to the currently available options,the proposed AVs logic proved to produce the most accurate results,in terms of the stop/go simulation outcome.Regarding the impact of automation on the stop/go outcome,the simulation experiments showed that AVs preferred a more conservative behaviour in favor of road safety,as indicated by the significant reduction(≈15%)in the number of vehicles crossing the stop line during the yellow light and zero instances of red light violation.However,compared to the conservative drivers represented by the default stop/go parameter values,AVs preferred a more rational behaviour in favor of intersection capacity without compromising road safety.
文摘Sight obstructions along road curves can lead to a crash if the driver is not able to stop the vehicle in time.This is a particular issue along curves with limited available sight,where speed management is necessary to avoid unsafe situations(e.g.,driving off the road or invading the other traffic lane).To solve this issue,we proposed a novel intelligent speed adaptation(ISA)system for visibility,called V-ISA(intelligent speed adaptation for visibility).It estimates the real-time safe speed limits based on the prevailing sight conditions.V-ISA comes with three variants with specific feedback modalities(1)visual and(2)auditory information,and(3)direct intervention to assume control over the vehicle speed.Here,we investigated the efficiency of each of the three V-ISA variants on driving speed choice and lateral behavioural response along road curves with limited and unsafe available sight distances,using a driving simulator.We also considered curve road geometry(curve direction:rightward vs.leftward).Sixty active drivers were recruited for the study.While half of them(experimental group)tested the three V-ISA variants(and a V-ISA off condition),the other half always drove with the V-ISA off(validation group).We used a linear mixed-effect model to evaluate the influence of V-ISA on driver behaviour.All V-ISA variants were efficient at reducing speeds at entrance points,with no discernible negative impact on driver lateral behaviour.On rightward curves,the V-ISA intervening variant appeared to be the most effective at adapting to sight limitations.Results of the current study implies that V-ISA might assist drivers to adjust their operating speed as per prevailing sight conditions and,consequently,establishes safer driving conditions.
文摘A shared control of highly automated Steer-by-Wire system is proposed for cooperative driving between the driver and vehicle in the face of driver's abnormal driving. A fault detection scheme is designed to detect the abnormal driving behaviour and transfer the control of the car to the automatic system designed based on a fault tolerant model predictive control(MPC) controller driving the vehicle along an optimal safe path.The proposed concept and control algorithm are tested in a number of scenarios representing intersection, lane change and different types of driver's abnormal behaviour. The simulation results show the feasibility and effectiveness of the proposed method.
基金sponsored by the National Natural Science Foundation of China (Grant No.71901223)the Natural Science Foundation of Hunan Province (Grant No.2021JJ40746)the Postgraduate Research and Innovation Project of Central South University (Grant No.1053320216523).
文摘Improper lane-changing behaviours may result in breakdown of traffic flow and the occurrence of various types of collisions.This study investigates lane-changing behaviours of multiple vehicles and the stimulative effect on following drivers in a consecutive lanechanging scenario.The microscopic trajectory data from the HighD dataset are used for driving behaviour analysis.Two discretionary lane-changing vehicle groups constitute a consecutive lane-changing scenario,and not only distance-and speed-related factors but also driving behaviours are taken into account to examine the impacts on the utility of following lane-changing vehicles.A random parameters logit model is developed to capture the driver’s psychological heterogeneity in the consecutive lane-changing situation.Furthermore,a lane-changing utility prediction model is established based on three supervised learning algorithms to detect the improper lane-changing decision.Results indicate that 1)the consecutive lane-changing behaviours have a significant negative effect on the following lane-changing vehicles after lane change;2)the stimulative effect exists in a consecutive lane-change situation and its influence is heterogeneous due to different psychological activities of drivers;and 3)the utility prediction model can be used to detect an improper lane-changing decision.
基金Project (Nos. 50775096 and 51075176) supported by the National Natural Science Foundation of China
文摘We propose a model structure with a double-layer hidden Markov model (HMM) to recognise driving intention and predict driving behaviour. The upper-layer multi-dimensional discrete HMM (MDHMM) in the double-layer HMM represents driving intention in a combined working case, constructed according to the driving behaviours in certain single working cases in the lower-layer multi-dimensional Gaussian HMM (MGHMM). The driving behaviours are recognised by manoeuvring the signals of the driver and vehicle state information, and the recognised results are sent to the upper-layer HMM to recognise driving intentions. Also, driving behaviours in the near future are predicted using the likelihood-maximum method. A real-time driving simulator test on the combined working cases showed that the double-layer HMM can recognise driving intention and predict driving behaviour accurately and efficiently. As a result, the model provides the basis for pre-warning and intervention of danger and improving comfort performance.
基金supported by JSPS KAKENHI Grant Numbers 25287026,15K17583,and 18H05923.
文摘There has been an increase in the number of on-road vehicles of all types,especially in some developing countries.The rise of traffic heterogeneity causes larger mixed traffic conge stion.This study examines the impact of next-nearest leading vehicles on the driving of following drivers in mixed traffic.Although previous studies reported that traffic stability can be improved with the introduction of followers’anticipatory driving that refers to multiple leaders,the effect of anticipatory driving on mixed traffic has not yet been examined.Using data collected from experiments conducted with groups of two and three vehicles,we found that operational delay,maximum acceleration and deceleration of the followers were affected by the presence of next-nearest leaders.In addition,we developed regression models of the affected followers’behaviours with respect to the next-nearest leaders and identified the factors affecting these behaviours.For example,the followers’deceleration is directly affected by the height of the next-nearest leading vehicles.Hence,the model parameters for determining the deceleration of following vehicles should take the height of the next-nearest leading vehicle into consideration.Finally,based on the regression models,we estimated values of parameters in the intelligent driver model when the type of the next-nearest leader was changed.Stability analysis based on these estimated parameters implied that a tall or short next-nearest leader with a large engine power would stabilise traffic when anticipatory driving of followers is possible.
文摘The ownership of motorised two wheelers(MTWs)has been on the rise across various countries across the globe.The growth has been especially higher in developing countries which have typical traffic characteristics and higher populations.This steady rise has resulted in increased accident and fatalities.This abrupt increase warranted attention from the researchers to carry out specific studies for MTWs,which have a very different behaviour as compared to cars in terms of physical and dynamic parameters.Moreover,the unique traffic patterns usually found in the developing countries pose an additional challenge to the researchers,since the conventional focus of transportation safety researchers was a homogeneous car-based traffic.Many such studies have been attempted,especially in the recent decades,which have considered various risk factors related to MTW safety.However,the studies have considered different sets of risk factors and have given surprising and even conflicting results.Therefore,a comprehensive review of the diverse studies needs to be carried out which incorporates all the risk factors considered in previous research.This study reviews such research papers which have analysed various risk factors related to safety of MTWs,especially in heterogeneous,non-lane based traffic.Specifically,this paper aims to incorporate results from those studies and highlight the conclusions from state of the art.The paper also discusses about the research gaps that are crucial for MTW safety in mixed traffic conditions.The review will be useful for researchers working in the field of MTW safety and for policy implementation and analysis.