The 84-km long Changbai Mountain scenic Ring highway encircles and bisects the nature reserve. With the expected increasing traffic flow, increased wildlife vehicle collisions and barrier effects are likely. In order ...The 84-km long Changbai Mountain scenic Ring highway encircles and bisects the nature reserve. With the expected increasing traffic flow, increased wildlife vehicle collisions and barrier effects are likely. In order to identify wildlife crossing zones and future protective measurement, the authors carried out 10 wildlife highway crossing surveys during the winter in 2008-2009. For each 5-kin section, the authors recorded highway crossings of all small/mid-sized and large mammals and one large protected bird species, the hazel grouse （Bonasa bonasia） and noted snow depth and the dominant vegetation type. The authors detected 12 mammal species and one avifauna species crossing the highway 502 times. The smallest of mammal was the Eurasian red squirrel （Sciurus vulgaris）. Large mammals detected included the wild boar （Sus scrofe） （64） and brown bear （Ursus arctos） （1）. The average number of wildlife crossings per 5 km was 29.5. It was found that species richness and crossing frequency was higher in sections with broad leaf forest compared to sections with white birch secondary forest significantly. The authors suggested that disturbance of broad leaf forest be minimized during construction and strict protection be established for broad leaf forests around Changbai Mountain National Nature Reserve.展开更多
This case study examines how the Hampton Roads Sea Level Rise Preparedness and Resilience Intergovernmental Planning Pilot Project, a whole-of-government and whole-of-community approach to planning for and adapting to...This case study examines how the Hampton Roads Sea Level Rise Preparedness and Resilience Intergovernmental Planning Pilot Project, a whole-of-government and whole-of-community approach to planning for and adapting to sea level rise, addressed coastal resilience in a southeastern Virginia watershed that spans multiple jurisdictions. Meeting the challenge of sea level rise requires that actors across multiple sectors—citizens, community organizations, industry and government—understand the risks and work together to make critical decisions regarding adaptation strategies and actions. The case study area includes Little Creek Amphibious Base, which is bordered by the cities of Norfolk and Virginia Beach. Adaptation responses to sea level rise by the military base and the local governments will impact each other and the residents of the area, but no cooperative agreements are in place for a joint or collaborative response. This case study examines public and private infrastructure at risk, the infrastructure interdependencies, and mechanisms for providing collaborative solutions. Engagement of area residents and other stakeholders is also integral to the process of adaptation, which includes educating about sea level rise risk and provides a mechanism for social learning that enables stakeholders to participate in critical adaptation decisions. The case study demonstrates a method to improve resiliency in the case study area and inform a regional, multi-sectoral response to sea level rise adaptation strategies.展开更多
As the "Internet +" action plan proceeds, e-commerce further integrates traditional sectors and increasingly promotes development. In the context of the Belt and Road Initiative, Chinese cross-border e-comme...As the "Internet +" action plan proceeds, e-commerce further integrates traditional sectors and increasingly promotes development. In the context of the Belt and Road Initiative, Chinese cross-border e-commerce, through channel expansion and market share increase, is taking the lead in trade and investment development, and facilitating labor division & coordination, resource & product sharing, as well as opening new markets. To promote the long-term economic development of countries along the Belt and Road, a series of development strategies have been designed, which concern constructing an "online silk road" for cross-border e-commerce, building new trade passages and bridges, innovating traditional trade models, and gathering a trade development momentum.展开更多
While pedestrian crashes on suburban roads have received more attention over recent years,the role of pedestrian crossing risk in areas adjacent to pedestrian crossing facilities,such as pedestrian overpasses,has been...While pedestrian crashes on suburban roads have received more attention over recent years,the role of pedestrian crossing risk in areas adjacent to pedestrian crossing facilities,such as pedestrian overpasses,has been neglected.Most pedestrians in suburban areas tend to avoid pedestrian overpasses,exhibiting crossing behaviors that increase the likelihood of pedestrian-involving crashes.As a result of the presence of overpasses,drivers may think that there are no pedestrians in the surroundings,so they choose a speed based only on the prevailing traffic and road environment without accounting for potential interactions with pedestrians.Consequently,crashes will occur,with pedestrians typically being the most seriously affected casualties.In this study,using video recordings from a suburban road in Amol-Babol,Iran,the risk of pedestrian crossing behavior in areas near pedestrian overpasses is investigated.The speed selection behavior of drivers in these areas has also been examined using speedometer cameras.To quantify the level of risk for pedestrians when interacting with approaching vehicles during the crossing movements,the post encroachment time(PET)was used as a surrogate safety measure.Based on critical thresholds of PET,three different risk levels were identified using a K-means algorithm:high,medium,and low risk.To identify the elements affecting the risk of pedestrian crossing behavior,structural equation models were estimated for all three risk levels.The results showed that human factors,relating to both drivers and pedestrians,have a dominant impact on pedestrian safety,especially in high and medium risk contexts.Road and vehicle factors were also found to have statistically observable effects on pedestrian safety,but to a milder extent compared to human factors.The findings of this study highlight the need for intervening in several aspects of vehicle-pedestrian interactions with critical importance for pedestrian safety,including road users’performance and compliance,state of alertness,and interaction with road infrastructure.展开更多
Road traffic is the main factor causing the decline in amphibian populations worldwide. The proper design of an amphibian tunnel is one of the most efficient measures to mitigate the negative impacts of road traffic o...Road traffic is the main factor causing the decline in amphibian populations worldwide. The proper design of an amphibian tunnel is one of the most efficient measures to mitigate the negative impacts of road traffic on amphibians. However, no study has investigated the effectiveness of amphibian tunnels under semi-controlled conditions in Asian amphibians. Here, we selected two representative amphibian species, the Chinese brown frog, Rana chensinensis, and the Asiatic toad, Bufo gargarizans, which suffer the most severe road mortality along the roads in Northeast China. We placed experimental arrays of culverts of various sizes(diameters of 1.5, 1, and 0.5 m for circular culverts; side lengths of 1.5, 1, and 0.5 m for box culverts), and substrate type(soil, concrete, and metal) to examine the preferences of both species during the migratory season between May and September in 2016 and 2017. The results revealed that the Chinese brown frog preferred mid-and large-sized culverts as well as soil culverts. We concluded that culverts with a side length ≥ 1 m, lined with soil, and accompanied by a ≥ 0.4 m high guide drift fence and ≤ 45° gradient on the roadside ditch wall would best facilitate road crossings for both species and likely for other amphibian species in Northeast China.展开更多
A cost estimate is one of the most important steps in road project management. There are ranges of factors that mostly affect the final project cost. Many approaches were used to estimate project cost, which took into...A cost estimate is one of the most important steps in road project management. There are ranges of factors that mostly affect the final project cost. Many approaches were used to estimate project cost, which took into consideration probable project performance and risks. The aim is to improve the ability of construction managers to predict a parametric cost estimate for road projects using SVM （support vector machine）. The work is based on collecting historical road executed cases. The 12 factors were identified to be the most important factors affecting the cost-estimating model. A total of 70 case studies from historical data were divided randomly into three sets： training set includes 60 cases, cross validation set includes three cases and testing set includes seven cases. The built model was successfully able to predict project cost to the AP （accuracy performance） of 95%.展开更多
A well developed network of roads must exist as a necessary infrastructure system in modem forestry to facilitate forest op- erations. But forest roads have the potential to disrupt the drainage characteristics of wat...A well developed network of roads must exist as a necessary infrastructure system in modem forestry to facilitate forest op- erations. But forest roads have the potential to disrupt the drainage characteristics of watersheds and lead to negative impacts on the environment with increased erosion and sediment yields. Numerous factors affect surface erosion of roads and sediment production potential; determining and ranking them could be a guide for management decisions to erosion control. In this study, the CULSED model （as an extension of ArcGIS） was used to estimate sediment delivery and the distribution of a road network, given the exist- ing culverts. Using the model, some culverts were added to the road network around places with high sediment delivery in order to minimize it. After a correlation analysis and adjustment between sediment production and the factors, i.e., road width, road gradient, age of road and vegetation cover, the trend of changes in sediment delivery with model changes in the input was investigated with a sensitivity analysis of the model. The results show that adding new culverts to the road resulted in a significant reduction of sediment delivery. The most important factor affecting sediment delivery was road width, followed by road gradient, vegetation cover and age of road. Road width and gradient were positively correlated with sediment delivery, while vegetation cover and age of road were neg- atively correlated. The best model to show the relation between sediment delivery and road width as well as with road gradient was a linear model, for vegetation cover a cubic equation and for road age a power model. The results of sensitivity analysis showed that sediment delivery had the greatest sensitivity to changes of road width and was least sensitive to changes in the age of the road. This model can help to estimate sediment delivery with its spatial distribution, which can be used for optimization of cross drain systems and strategies of sediment control. Application of the model requires field trials to acquire the necessary input data. The reliability of our results is a function of the accuracy of inputs, especially digital elevation model.展开更多
This study assessed critical factors for road traffic accidents and associated mitigation to reduce the accidents by the year 2030. The study was guided by research questions, what are the major causatives of road acc...This study assessed critical factors for road traffic accidents and associated mitigation to reduce the accidents by the year 2030. The study was guided by research questions, what are the major causatives of road accidents and how to mitigate the problem. The study used secondary data collected from the repository database of traffic police at the division of Tanzania Road Safety Squad. Data were collected at the events of accident occur</span><span style="font-family:Verdana;">re</span><span style="font-family:Verdana;">nces and reported annually by regions. Panel data analysis was used to allow for controlling variables which cannot be observed over time and across areas such as regions. Pooled Poisson model, fixed effect and random effect Poisson model was applied to assess factors for road traffic accidents. Fixed effect model was the best model with a reasonably good fit. Results indicated that all predictors are significant under fixed effect Poisson model with </span><span style="font-family:Verdana;">a </span><span style="font-family:""><span style="font-family:Verdana;">p-value less than 0.05 but Passengers and Railway crossing road was found insignificant and dropped in the final model. Laws and regulatory frameworks should be formulated and enforced promptly for Tanzania may reach the target of 2</span><sup><span style="font-family:Verdana;">nd</span></sup><span style="font-family:Verdana;"> decade of action for roads safety 2021-2030.展开更多
文摘The 84-km long Changbai Mountain scenic Ring highway encircles and bisects the nature reserve. With the expected increasing traffic flow, increased wildlife vehicle collisions and barrier effects are likely. In order to identify wildlife crossing zones and future protective measurement, the authors carried out 10 wildlife highway crossing surveys during the winter in 2008-2009. For each 5-kin section, the authors recorded highway crossings of all small/mid-sized and large mammals and one large protected bird species, the hazel grouse （Bonasa bonasia） and noted snow depth and the dominant vegetation type. The authors detected 12 mammal species and one avifauna species crossing the highway 502 times. The smallest of mammal was the Eurasian red squirrel （Sciurus vulgaris）. Large mammals detected included the wild boar （Sus scrofe） （64） and brown bear （Ursus arctos） （1）. The average number of wildlife crossings per 5 km was 29.5. It was found that species richness and crossing frequency was higher in sections with broad leaf forest compared to sections with white birch secondary forest significantly. The authors suggested that disturbance of broad leaf forest be minimized during construction and strict protection be established for broad leaf forests around Changbai Mountain National Nature Reserve.
文摘This case study examines how the Hampton Roads Sea Level Rise Preparedness and Resilience Intergovernmental Planning Pilot Project, a whole-of-government and whole-of-community approach to planning for and adapting to sea level rise, addressed coastal resilience in a southeastern Virginia watershed that spans multiple jurisdictions. Meeting the challenge of sea level rise requires that actors across multiple sectors—citizens, community organizations, industry and government—understand the risks and work together to make critical decisions regarding adaptation strategies and actions. The case study area includes Little Creek Amphibious Base, which is bordered by the cities of Norfolk and Virginia Beach. Adaptation responses to sea level rise by the military base and the local governments will impact each other and the residents of the area, but no cooperative agreements are in place for a joint or collaborative response. This case study examines public and private infrastructure at risk, the infrastructure interdependencies, and mechanisms for providing collaborative solutions. Engagement of area residents and other stakeholders is also integral to the process of adaptation, which includes educating about sea level rise risk and provides a mechanism for social learning that enables stakeholders to participate in critical adaptation decisions. The case study demonstrates a method to improve resiliency in the case study area and inform a regional, multi-sectoral response to sea level rise adaptation strategies.
基金"E-commerce and Trade Facilitation along the Silk Road Economic Belt"(13SC025),a research program sponsored by Shaanxi Provincial Social Sciences Fund
文摘As the "Internet +" action plan proceeds, e-commerce further integrates traditional sectors and increasingly promotes development. In the context of the Belt and Road Initiative, Chinese cross-border e-commerce, through channel expansion and market share increase, is taking the lead in trade and investment development, and facilitating labor division & coordination, resource & product sharing, as well as opening new markets. To promote the long-term economic development of countries along the Belt and Road, a series of development strategies have been designed, which concern constructing an "online silk road" for cross-border e-commerce, building new trade passages and bridges, innovating traditional trade models, and gathering a trade development momentum.
文摘While pedestrian crashes on suburban roads have received more attention over recent years,the role of pedestrian crossing risk in areas adjacent to pedestrian crossing facilities,such as pedestrian overpasses,has been neglected.Most pedestrians in suburban areas tend to avoid pedestrian overpasses,exhibiting crossing behaviors that increase the likelihood of pedestrian-involving crashes.As a result of the presence of overpasses,drivers may think that there are no pedestrians in the surroundings,so they choose a speed based only on the prevailing traffic and road environment without accounting for potential interactions with pedestrians.Consequently,crashes will occur,with pedestrians typically being the most seriously affected casualties.In this study,using video recordings from a suburban road in Amol-Babol,Iran,the risk of pedestrian crossing behavior in areas near pedestrian overpasses is investigated.The speed selection behavior of drivers in these areas has also been examined using speedometer cameras.To quantify the level of risk for pedestrians when interacting with approaching vehicles during the crossing movements,the post encroachment time(PET)was used as a surrogate safety measure.Based on critical thresholds of PET,three different risk levels were identified using a K-means algorithm:high,medium,and low risk.To identify the elements affecting the risk of pedestrian crossing behavior,structural equation models were estimated for all three risk levels.The results showed that human factors,relating to both drivers and pedestrians,have a dominant impact on pedestrian safety,especially in high and medium risk contexts.Road and vehicle factors were also found to have statistically observable effects on pedestrian safety,but to a milder extent compared to human factors.The findings of this study highlight the need for intervening in several aspects of vehicle-pedestrian interactions with critical importance for pedestrian safety,including road users’performance and compliance,state of alertness,and interaction with road infrastructure.
基金funded by the National Natural Science Foundation of China (Grant No. 51508250)the Science and Technology Project of Department of Transportation of Jilin Province (Grant No. 2018-1-14)+1 种基金the Basic Research Program of the Centric Level, Scientific Research Institutes (Grant No. 20180615)the World Wild Fund for Nature Project (Grant No. P03516)
文摘Road traffic is the main factor causing the decline in amphibian populations worldwide. The proper design of an amphibian tunnel is one of the most efficient measures to mitigate the negative impacts of road traffic on amphibians. However, no study has investigated the effectiveness of amphibian tunnels under semi-controlled conditions in Asian amphibians. Here, we selected two representative amphibian species, the Chinese brown frog, Rana chensinensis, and the Asiatic toad, Bufo gargarizans, which suffer the most severe road mortality along the roads in Northeast China. We placed experimental arrays of culverts of various sizes(diameters of 1.5, 1, and 0.5 m for circular culverts; side lengths of 1.5, 1, and 0.5 m for box culverts), and substrate type(soil, concrete, and metal) to examine the preferences of both species during the migratory season between May and September in 2016 and 2017. The results revealed that the Chinese brown frog preferred mid-and large-sized culverts as well as soil culverts. We concluded that culverts with a side length ≥ 1 m, lined with soil, and accompanied by a ≥ 0.4 m high guide drift fence and ≤ 45° gradient on the roadside ditch wall would best facilitate road crossings for both species and likely for other amphibian species in Northeast China.
文摘A cost estimate is one of the most important steps in road project management. There are ranges of factors that mostly affect the final project cost. Many approaches were used to estimate project cost, which took into consideration probable project performance and risks. The aim is to improve the ability of construction managers to predict a parametric cost estimate for road projects using SVM （support vector machine）. The work is based on collecting historical road executed cases. The 12 factors were identified to be the most important factors affecting the cost-estimating model. A total of 70 case studies from historical data were divided randomly into three sets： training set includes 60 cases, cross validation set includes three cases and testing set includes seven cases. The built model was successfully able to predict project cost to the AP （accuracy performance） of 95%.
文摘A well developed network of roads must exist as a necessary infrastructure system in modem forestry to facilitate forest op- erations. But forest roads have the potential to disrupt the drainage characteristics of watersheds and lead to negative impacts on the environment with increased erosion and sediment yields. Numerous factors affect surface erosion of roads and sediment production potential; determining and ranking them could be a guide for management decisions to erosion control. In this study, the CULSED model （as an extension of ArcGIS） was used to estimate sediment delivery and the distribution of a road network, given the exist- ing culverts. Using the model, some culverts were added to the road network around places with high sediment delivery in order to minimize it. After a correlation analysis and adjustment between sediment production and the factors, i.e., road width, road gradient, age of road and vegetation cover, the trend of changes in sediment delivery with model changes in the input was investigated with a sensitivity analysis of the model. The results show that adding new culverts to the road resulted in a significant reduction of sediment delivery. The most important factor affecting sediment delivery was road width, followed by road gradient, vegetation cover and age of road. Road width and gradient were positively correlated with sediment delivery, while vegetation cover and age of road were neg- atively correlated. The best model to show the relation between sediment delivery and road width as well as with road gradient was a linear model, for vegetation cover a cubic equation and for road age a power model. The results of sensitivity analysis showed that sediment delivery had the greatest sensitivity to changes of road width and was least sensitive to changes in the age of the road. This model can help to estimate sediment delivery with its spatial distribution, which can be used for optimization of cross drain systems and strategies of sediment control. Application of the model requires field trials to acquire the necessary input data. The reliability of our results is a function of the accuracy of inputs, especially digital elevation model.
文摘This study assessed critical factors for road traffic accidents and associated mitigation to reduce the accidents by the year 2030. The study was guided by research questions, what are the major causatives of road accidents and how to mitigate the problem. The study used secondary data collected from the repository database of traffic police at the division of Tanzania Road Safety Squad. Data were collected at the events of accident occur</span><span style="font-family:Verdana;">re</span><span style="font-family:Verdana;">nces and reported annually by regions. Panel data analysis was used to allow for controlling variables which cannot be observed over time and across areas such as regions. Pooled Poisson model, fixed effect and random effect Poisson model was applied to assess factors for road traffic accidents. Fixed effect model was the best model with a reasonably good fit. Results indicated that all predictors are significant under fixed effect Poisson model with </span><span style="font-family:Verdana;">a </span><span style="font-family:""><span style="font-family:Verdana;">p-value less than 0.05 but Passengers and Railway crossing road was found insignificant and dropped in the final model. Laws and regulatory frameworks should be formulated and enforced promptly for Tanzania may reach the target of 2</span><sup><span style="font-family:Verdana;">nd</span></sup><span style="font-family:Verdana;"> decade of action for roads safety 2021-2030.
