The hotspot recognition algorithm is proposed based on a potential collision in order to study the aircraft taxi conflicts in large airports.The spatial and temporal distribution characteristics of hotspots are analyz...The hotspot recognition algorithm is proposed based on a potential collision in order to study the aircraft taxi conflicts in large airports.The spatial and temporal distribution characteristics of hotspots are analyzed based on the risk assessment model of hotspot constructed in this paper.Firstly,approaches for monitoring of the aerodrome movement were compared.The hotspot recognition algorithm taken into account of whether aircrafts'taxi track has spatial and temporal overlap based on the aerodrome surveillance radar(ASR)data was presented,by identifying the hotspots through analyzing whether the aircrafts'time of entering and exiting the same taxiway is overlap or not,and the heading difference and distance of the two aircrafts satisfy the specified threshold constraint condition.Then,the ASR data were divided into several parts,and then airport hotspots were recognized and the spatial and temporal distribution characteristics were analyzed.The risk assessment model of airport safety hotspots was constructed which is taken into account of the conflict probability and its severity consequence.Finally,based on the risk grade assessment criteria and hotspots'risk value,the risk grade ranking of hotspot in one airport of China was evaluated and designated.According to the result,the spatial and temporal distribution characteristics of airport hotspots were varied with the variation of airport traffic flow and operational mode of runway,which shows that the hotspots have the characteristics of dynamic periodicity and diurnal variation.And the risk assessment results were consistent with experts'opinions and actual operation condition,which verified the rationality of the hotspot recognition algorithm,risk assessment model as well as the risk grade ranking criteria.展开更多
Although road users are aware of the possible risks of engaging in unsafe behaviours while driving,they continue to do so.These behaviours often contribute to traffic incidents and crashes involving them and other roa...Although road users are aware of the possible risks of engaging in unsafe behaviours while driving,they continue to do so.These behaviours often contribute to traffic incidents and crashes involving them and other road users.This study set out to analyse the effect of road user type,location and time of day on unsafe driving behaviours observed in traffic conflict situations.Data were collected by road side observation at three different locations in the eastern part of Nigeria using the traffic conflict technique(TCT).This approach was adopted to overcome the inherent problems associated with reliable,inadequate and accessible crash data in Nigeria.In total 946 traffic conflicts were observed and statistical testing showed that drivers were involved in one or more unsafe behaviours prior to these conflicts.Of all unsafe behaviours observed,the incorrect use of indicators(13.3%) and tailgating(11.3%) were found to be the most prevalent,while road user type,location and time of day were found to be statistically associated with passenger scouting and other unsafe behaviours.Tricycle drivers were significantly more likely to engage in unsafe behaviours than vehicle drivers.Drivers are also more likely to engage in unsafe behaviours on straight roads.Additionally,a greater number of these unsafe behaviours were observed during the peak periods.It is recommended that better road infrastructure,more effective regulations and enforcement,and proper road safety education could help improve traffic safety in Nigeria.展开更多
基金the Joint Funds of the National Science Foundation of China and the Civil Aviation Administration(Nos.U1733105 and U1733203)the Sichuan Science and Technology Program(No.2019YFG0308)
文摘The hotspot recognition algorithm is proposed based on a potential collision in order to study the aircraft taxi conflicts in large airports.The spatial and temporal distribution characteristics of hotspots are analyzed based on the risk assessment model of hotspot constructed in this paper.Firstly,approaches for monitoring of the aerodrome movement were compared.The hotspot recognition algorithm taken into account of whether aircrafts'taxi track has spatial and temporal overlap based on the aerodrome surveillance radar(ASR)data was presented,by identifying the hotspots through analyzing whether the aircrafts'time of entering and exiting the same taxiway is overlap or not,and the heading difference and distance of the two aircrafts satisfy the specified threshold constraint condition.Then,the ASR data were divided into several parts,and then airport hotspots were recognized and the spatial and temporal distribution characteristics were analyzed.The risk assessment model of airport safety hotspots was constructed which is taken into account of the conflict probability and its severity consequence.Finally,based on the risk grade assessment criteria and hotspots'risk value,the risk grade ranking of hotspot in one airport of China was evaluated and designated.According to the result,the spatial and temporal distribution characteristics of airport hotspots were varied with the variation of airport traffic flow and operational mode of runway,which shows that the hotspots have the characteristics of dynamic periodicity and diurnal variation.And the risk assessment results were consistent with experts'opinions and actual operation condition,which verified the rationality of the hotspot recognition algorithm,risk assessment model as well as the risk grade ranking criteria.
基金the Tertiary Education Trust Fund (TETFund) of Nigeria and Institute for Transport Studies, University of Leeds,UK,for funding this research
文摘Although road users are aware of the possible risks of engaging in unsafe behaviours while driving,they continue to do so.These behaviours often contribute to traffic incidents and crashes involving them and other road users.This study set out to analyse the effect of road user type,location and time of day on unsafe driving behaviours observed in traffic conflict situations.Data were collected by road side observation at three different locations in the eastern part of Nigeria using the traffic conflict technique(TCT).This approach was adopted to overcome the inherent problems associated with reliable,inadequate and accessible crash data in Nigeria.In total 946 traffic conflicts were observed and statistical testing showed that drivers were involved in one or more unsafe behaviours prior to these conflicts.Of all unsafe behaviours observed,the incorrect use of indicators(13.3%) and tailgating(11.3%) were found to be the most prevalent,while road user type,location and time of day were found to be statistically associated with passenger scouting and other unsafe behaviours.Tricycle drivers were significantly more likely to engage in unsafe behaviours than vehicle drivers.Drivers are also more likely to engage in unsafe behaviours on straight roads.Additionally,a greater number of these unsafe behaviours were observed during the peak periods.It is recommended that better road infrastructure,more effective regulations and enforcement,and proper road safety education could help improve traffic safety in Nigeria.
