On the basis of the equivalent axle load action frequency, the traffic classifications of rural roads as well as their corresponding types are classified. The asphalt pavement structure, road surface types and thickne...On the basis of the equivalent axle load action frequency, the traffic classifications of rural roads as well as their corresponding types are classified. The asphalt pavement structure, road surface types and thickness of the rural roads are suggested for the various action frequency of the equivalent axle load. Furthermore, the roadbase thickness graphs are provided according to different equivalent axle load action frequency with different roadbed modulus and road surface modulus taken into account.展开更多
More than 32,000 motorists are killed on U.S. roads and streets annually, and approximately 54% of the accidents occur on rural roads. In an attempt to address and reduce these fatalities, the current transportation a...More than 32,000 motorists are killed on U.S. roads and streets annually, and approximately 54% of the accidents occur on rural roads. In an attempt to address and reduce these fatalities, the current transportation act, the Safe, Accountable, Flexible, Efficient Transportation Equality Act: A Legacy for Users (SAFETY-LU), elevated the Highway Safety Improvement Program (HSIP) to a core program and included a $90,000,000 High-Risk Rural Road Program (HRRRP) to address and significantly reduce traffic fatalities and incapacitating injuries on rural major or minor collectors, and/or rural local roads. While there were many challenges to properly implement the HRRRP in counties, this study provided important information that was needed to identify the predominant crash types on HRRRP-eligible roads and compiled a list of countermeasures for the predominant crash types that were identified on Kansas’ high-risk rural roads. For the gathered countermeasures, crash reduction factors (CRFs) were also provided from the literature review, and their values were validated by conducting interviews with Kansas county engineers/officials. This study provided valuable information for the county engineers and local government officials while they worked on improving the safety of high-risk rural roads using HRRRP funds.展开更多
The relationship between rural road①systems and economic systems is interconnectedness.The stimulating effects of investments in rural road infrastructure can be divided into three stages:investment,use,and upgrading...The relationship between rural road①systems and economic systems is interconnectedness.The stimulating effects of investments in rural road infrastructure can be divided into three stages:investment,use,and upgrading.This paper presents this three-stage model of rural road construction to explain the process of stimulating economic growth by investing in rural roads.The investment stage produces a multiplier effect as the investment stimulates the economy.The use stage promotes the development of industries,which determines the stimulation effects of the investment.The upgrading stage produces economic growth leading to the upgrading of additional infrastructure,which generates more investments and also has a multiplier effect.Finally,the total revenue from the three stages,minus their total costs,allows for the calculation of Net Present Value(NPV).The investments can be deemed effective if the NPV is greater than zero.展开更多
AT peak tourist season, 32-year-old Li Lianfen sees her husband and son just once a week. She has converted her home in Shicheng (Stone City) Village in Beijing’s Miyun County into an inn. City people come here to st...AT peak tourist season, 32-year-old Li Lianfen sees her husband and son just once a week. She has converted her home in Shicheng (Stone City) Village in Beijing’s Miyun County into an inn. City people come here to stay and enjoy the beauty and tran-quility of the mountains around her village. As she has no time to look after her son, he attends a primary school in the county seat 20 kilometers away. His father is a teacher at the middle school nearby. They both stay there in the accommodation provided.展开更多
There has been no precise information regarding occupants’ status and their portion in traffic accident. By using traffic police information, epidemiological pattern of road traffic injuries among occupants’ vehicle...There has been no precise information regarding occupants’ status and their portion in traffic accident. By using traffic police information, epidemiological pattern of road traffic injuries among occupants’ vehicles was analyzed in 2012. It was a cross sectional study. In this study, traffic police registered data in 2012 were used. Subjects were all occupants who had accident record in 2012 (81585: 77841 injured and 3744 death). Before analyzing, various preparatory steps including data control and merging were done after which data were processed. Findings showed that the mean age of the studied population was 28.7 ± 15.11 years. The highest percentage of accident occurred among car and motorcycle occupants respectively. The risk of death among the injured aged 30 - 59 years and 60+ were 1.20 and 2.23 times more than 30 years (as reference) respectively (p < 0.001). Risk of death among the injured in high ways, main roads and rural roads was 2.84 times more than in urban roads (p < 0.001). The risk of death among the injured was 2 times higher in high ways, main roads and rural secondary roads than streets (p < 0.001). Hence car and motorcycle occupants need urgent attention especially in motorways and high ways, main roads and rural secondary.展开更多
Safety performance functions（SPFs） are crucial to science-based road safety management.Success in developing and applying SPFs, apart data quality and availability, depends fundamentally on two key factors： the val...Safety performance functions（SPFs） are crucial to science-based road safety management.Success in developing and applying SPFs, apart data quality and availability, depends fundamentally on two key factors： the validity of the statistical inferences for the available data and on how well the data can be organized into distinct homogeneous entities. The latter aspect plays a key role in the identification and treatment of road sections or corridors with problems related to safety. Indeed, the segmentation of a road network could be especially critical in the development of SPFs that could be used in safety management for roadway types, such as motorways（freeways in North America）, which have a large number of variables that could result in very short segments if these are desired to be homogeneous. This consequence, from an analytical point of view, can be a problem when the location of crashes is not precise and when there is an overabundance of segments with zero crashes. Lengthening the segments for developing and applying SPFs can mitigate this problem, but at a sacrifice of homogeneity. This paper seeks to address this dilemma by investigating four approaches for segmentation for motorways, using sample data from Italy. The best results were obtained for the segmentation based on two curves and two tangents within a segment and with fixed length segments. The segmentation characterized by a constant value of all original variables inside each segment was the poorest approach by all measures.展开更多
文摘On the basis of the equivalent axle load action frequency, the traffic classifications of rural roads as well as their corresponding types are classified. The asphalt pavement structure, road surface types and thickness of the rural roads are suggested for the various action frequency of the equivalent axle load. Furthermore, the roadbase thickness graphs are provided according to different equivalent axle load action frequency with different roadbed modulus and road surface modulus taken into account.
文摘More than 32,000 motorists are killed on U.S. roads and streets annually, and approximately 54% of the accidents occur on rural roads. In an attempt to address and reduce these fatalities, the current transportation act, the Safe, Accountable, Flexible, Efficient Transportation Equality Act: A Legacy for Users (SAFETY-LU), elevated the Highway Safety Improvement Program (HSIP) to a core program and included a $90,000,000 High-Risk Rural Road Program (HRRRP) to address and significantly reduce traffic fatalities and incapacitating injuries on rural major or minor collectors, and/or rural local roads. While there were many challenges to properly implement the HRRRP in counties, this study provided important information that was needed to identify the predominant crash types on HRRRP-eligible roads and compiled a list of countermeasures for the predominant crash types that were identified on Kansas’ high-risk rural roads. For the gathered countermeasures, crash reduction factors (CRFs) were also provided from the literature review, and their values were validated by conducting interviews with Kansas county engineers/officials. This study provided valuable information for the county engineers and local government officials while they worked on improving the safety of high-risk rural roads using HRRRP funds.
文摘The relationship between rural road①systems and economic systems is interconnectedness.The stimulating effects of investments in rural road infrastructure can be divided into three stages:investment,use,and upgrading.This paper presents this three-stage model of rural road construction to explain the process of stimulating economic growth by investing in rural roads.The investment stage produces a multiplier effect as the investment stimulates the economy.The use stage promotes the development of industries,which determines the stimulation effects of the investment.The upgrading stage produces economic growth leading to the upgrading of additional infrastructure,which generates more investments and also has a multiplier effect.Finally,the total revenue from the three stages,minus their total costs,allows for the calculation of Net Present Value(NPV).The investments can be deemed effective if the NPV is greater than zero.
文摘AT peak tourist season, 32-year-old Li Lianfen sees her husband and son just once a week. She has converted her home in Shicheng (Stone City) Village in Beijing’s Miyun County into an inn. City people come here to stay and enjoy the beauty and tran-quility of the mountains around her village. As she has no time to look after her son, he attends a primary school in the county seat 20 kilometers away. His father is a teacher at the middle school nearby. They both stay there in the accommodation provided.
文摘There has been no precise information regarding occupants’ status and their portion in traffic accident. By using traffic police information, epidemiological pattern of road traffic injuries among occupants’ vehicles was analyzed in 2012. It was a cross sectional study. In this study, traffic police registered data in 2012 were used. Subjects were all occupants who had accident record in 2012 (81585: 77841 injured and 3744 death). Before analyzing, various preparatory steps including data control and merging were done after which data were processed. Findings showed that the mean age of the studied population was 28.7 ± 15.11 years. The highest percentage of accident occurred among car and motorcycle occupants respectively. The risk of death among the injured aged 30 - 59 years and 60+ were 1.20 and 2.23 times more than 30 years (as reference) respectively (p < 0.001). Risk of death among the injured in high ways, main roads and rural roads was 2.84 times more than in urban roads (p < 0.001). The risk of death among the injured was 2 times higher in high ways, main roads and rural secondary roads than streets (p < 0.001). Hence car and motorcycle occupants need urgent attention especially in motorways and high ways, main roads and rural secondary.
基金made possible by a Discovery Grant from the Natural Sciences and Engineering Research Council of Canada (NSERC)
文摘Safety performance functions（SPFs） are crucial to science-based road safety management.Success in developing and applying SPFs, apart data quality and availability, depends fundamentally on two key factors： the validity of the statistical inferences for the available data and on how well the data can be organized into distinct homogeneous entities. The latter aspect plays a key role in the identification and treatment of road sections or corridors with problems related to safety. Indeed, the segmentation of a road network could be especially critical in the development of SPFs that could be used in safety management for roadway types, such as motorways（freeways in North America）, which have a large number of variables that could result in very short segments if these are desired to be homogeneous. This consequence, from an analytical point of view, can be a problem when the location of crashes is not precise and when there is an overabundance of segments with zero crashes. Lengthening the segments for developing and applying SPFs can mitigate this problem, but at a sacrifice of homogeneity. This paper seeks to address this dilemma by investigating four approaches for segmentation for motorways, using sample data from Italy. The best results were obtained for the segmentation based on two curves and two tangents within a segment and with fixed length segments. The segmentation characterized by a constant value of all original variables inside each segment was the poorest approach by all measures.
