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Total suspended particulate (TSP) samples were collected along a highway (Barajima air pollution monitoring station) in the center of Akita City in northern Japan, from 9 – 11 May, 1996 (non-snow-clad period) and 7 – 9 February, 1997 (snow-clad period), with a one-hour sampling interval, The elemental composition and particle shape of TSP samples were determined and / or observed by Particle Induced X-ray Emission (PIXE) and a Scanning Electron Microscope (SEM) combined with Energy Dispersive X-ray (EDX) analysis. In the hourly TSP samples collected during the non-snow-clad period, 26 elements were determined. Na, Mg, Al, Si, S, Cl, K, Ca and Fe are the major components. On the other hand, 24 elements, excluding As, Rb and Nb, are found in the snow-clad period samples, and Gallium is only found in the snow-clad period samples. Dominant elements, i.e., major components, of the snow-clad period were the same as the non-snow-clad period. Comparing the arithmetic means of major elemental concentrations in TSP for the non-snow-clad and snow-clad periods, Na, Mg, Al, Si and Fe are similar. However, S and Ca levels in the non-snow-clad period samples were 4 and 6 times higher than those in the snow-clad period samples, respectively, while Cl and K levels in the snow-clad period samples were 1.5 and 2 times higher than those in the non-snow-clad period, respectively. In the non-snow-clad period, the temporal variation pattern of total elemental amount was consistent with the variation pattern of NO and CO, which are pollutants used to observe the effects of automobile exhaust gas, and it was comparatively consistent with the variation pattern of SPM. On the other hand, in the snow-clad period, the temporal variation pattern of total elemental amount was not consistent with the variation pattern of NO and CO when the wind was blowing from the southeast, so the TSP may be strongly influenced by wind direction and wind velocity in addition to automobile traffic. Factor analysis allowed us to identify four major sources, with automobile emission, industry and soil being the major contributors. With the aid of SEM and EDX analysis, aggregates of diesel exhaust particles (DEP), soil particles and small silicon-rich spherical particles were observed in the non-snow-clad and snow-clad period samples.

Unsuitable driving behaviors often lead to the occurrence of traffic accidents. To reduce accidents and to prolong human life, simulated investigations are highly desirable to evaluate the effect of traffic safety in terms of number of traffic accidents. In this paper, a three-lane traffic flow model is proposed to analyze the probability of the occurrence of traffic accidents on highway. We define appropriate driving rules for the forward moving and lane changing of the vehicles. Three types of vehicle accidents are designed to investigate the relationships between different driving behaviors and traffic accidents. We simulate four road driving strategies, and compute the traffic flow, velocity, lane-changing frequency and the probability of the occurrence of traffic accidents for different road driving strategies. According to the simulation and analysis, it is shown that the probability of the occurrence of traffic accidents can be reduced by using the specified road driving strategies. Additionally, we found that the occurrence of traffic accidents can be avoided when the slow vehicles are suitably constrained to move on a three-lane highway.

In order to deeply analyze the quantitative relationship between traffic flow state and crash risk, a highway traffic safety state classification method based on multi-parameter fusion clustering was proposed. First, attribute data of highway traffic crashes and corresponding upstream and downstream traffic flow data were extracted, and matched with paired case-control method. Secondly, considering the different roles of traffic volume, speed and occupancy in traffic state classification, the weight optimization algorithm is introduced to calculate the weight of the three parameters. Therefore, the comprehensive evaluation index of traffic state with the fusion of three parameters is obtained and used as the input index of traffic safety state clustering. Finally, $k$-means clustering method is used to classify the highway traffic safety status. The result of the case study shows that the proposed method can achieve reasonable and effective traffic safety state division. The classification results are helpful to quantitatively evaluate highway crash risk levels under different traffic safety states.

The highway system is an important component of the modern society as it allows an efficient intercity communication. However, with the increase in the number of cars, the traffic congestion becomes a widespread problem around the world. Here, we study the traffic conditions in Hsuehshan tunnel in Taiwan. When there is traffic congestion, there is a remarkable fraction of vehicles choosing an alternative path, even if it cost more time than jamming on the highway. In addition, we evaluate through statistics and the government’s policy to improve the road condition of the tunnel.

Modeling of 3D highway integrated with terrain model was firstly discussed in this paper, and a new method of judging the maximum angle was used to eliminate the distorted triangles on the boundary of model. It is a fundamental issue for visualization and analysis on 3D GIS at a rapid speed. To strip-distributed terrain data, this paper proposed a new dynamic multi-resolution model. Different from other models/algorithms, this algorithm need not pre-partition the model regularly and can achieve multi-resolution representation in one tile. In addition, such a condition was considered in the approach that only resolution level of parts of triangles will change in adjacent frames when roaming. That is, the resolution of parts of triangles which locate in the joints of adjacent resolution levels will change. Therefore, the speed of algorithm can be improved. Finally, a software prototype “VRHighWay”, developed by VC++ 6.0 and OpenGL, was introduced. The experimental results demonstrate that proposed method acquires better performance in terms of accuracy for the multi-resolution representation of terrains with roads embedded.

For the expansion project of the soft soil subgrade section of highway, the mixed soilcement pile curtain wall (MSCPCW) was installed at the boundary of old and extended pavement. The settlements of soft soil foundation and construction process were simulated using the elastic-plastic finite element analysis software. The numerical simulation results are in line with the field test results, which show that the numerical model is accurate to describe the deformation of cement mixing pile and soft soil foundation. The combined method of MSCPCW and foundation treatment can effectively control the new and old roadbed difference settlement for expansion highway project.

Increase generation of waste from human and construction activities with significantly increase number of global population becomes major issues over disposal space. The reuse of waste material is an important topic from the point of sustainability. Some types of waste such as tyre bales, construction and demolition materials, recycled glass and biosolids were studied to investigate the possibility for reuse in highway construction. It was found that tyre bales are useful for embankment stabilization especially on highly compressible soil, construction and demolition material such as brick and and recycled glass were found to be suitable for embankment and pavement base applications. Preliminary studies on biosolids indicate they are useful as embankment material provided which can be treated with suitable additives. This paper discussed the types of waste which are usable with or without treatment in highway engineering, their characteristics and their expected performance in their design life.

Reinforcement materials were evaluated with respect to effect on sod strength for different seeding densities. Evaluations were performed using sample plantings in a greenhouse setting. For determining suitable reinforcement materials, was conducted on native grass species for three of those ecoregions. The initial evaluation for determining native grass species was performed using species from six different ecoregions of California. Basic species evaluation was done using biomass, species abundance, and total ground cover. The objective was to evaluate a number of native grass species and reinforcement materials for their suitability for contributing to a harvestable multispecies sod for roadside rehabilitation.