The relationship between precipitation types and meteorological factors was surveyed based on the effect analysis of main meteorological parameters on asphalt pavement surface icing conditions and prediction analysis model of asphalt pavement temperature was established. This study aims to determine the correlation between icy pavement and meteorological factors and implement an accurate prediction of the icing condition of pavement. Considering the road slipperiness criterion presented by Norrman, a discriminative standard of icing condition of asphalt pavement surface in the central area of Zhejiang Province was proposed. Based on the above analysis results, a prediction model of pavement surface icing condition involved in asphalt pavement and ambient temperatures under the condition of different precipitation types was constructed by using support vector machine (SVM) method. Results demonstrate that (1) the distribution characteristics of daily mean air temperature, daily mean pavement temperature, daily average wind speed, and average daily rainfall have remarkable differences under the condition of different precipitation types, wherein the variation features of daily mean air temperature and daily mean pavement temperature are obvious; (2) the indirect prediction of precipitation type and pavement surface temperature could be accomplished in terms of meteorological monitoring data; (3) the influence of pavement surface icing conditions on driving safety is lower than that of rainwater freezing on a cold surface, melting snow at air temperature above 0℃, and melting snow at air temperature below 0℃; and (4) the SVM-based prediction model of pavement surface icing condition has an accurate analysis result with misreporting rate below 6%. The generalization ability of the proposed model is good and fully demonstrates the application prospects of SVM in the pavement weather prediction field. This study can provide theoretical and technical support for real-time warning about icy asphalt pavements in winter.

Free water accumulated between pavement surface and base can flow at high speed due to differential pressure, thereby producing a pumping effect. This condition may scour the base surface, causing damage to the road surface. On the basis of the principles of scouring of a semi-rigid base material, vibrating water flow erosion and wheel rolling scouring tests were conducted using a concrete shaking table and an asphalt mixture rutting tester to evaluate the anti-erosion performance and anti-scouring effect of a semi-rigid base. According to the comparison results of the two types of base materials and three anti-erosion measures, the erosion resistance of cement stabilized graded gravel is superior to that of cement stabilized grit. Using emulsification asphalt penetration treatment and earthwork cloth produces a significant effect on reducing the surface erosion of a semi-rigid base material. The scouring mass of the base material can usually be reduced by 60% to 80% or more, in one case up to 94.4%. With regard to the anti-erosion effect, "emulsified asphalt permeation treatment + earthwork cloth" is the most superior solution of the three, followed by earthwork cloth reinforcement, and then "emulsified asphalt permeation treatment" utilization. In comparison with the non freeze-thawed specimens, the scouring mass of the freeze-thawed specimens increases slightly. The effect of the anti-erosion measures remains promising under the conditions of freeze-thaw cycles. For the cement concrete pavement, applying simulated dowel bars in contraction joints reduces erosion by 40.7% to 66.3%. Results show that the scouring mass of the base material in the vibration flow scouring test is larger than that of the wheel rolling scouring test, while the overall trend remains constant. For nonquantitative analysis of semi-rigid base materials, either one of the two erosion test methods can be utilized to analyze and compare the erosion resistance and anti-erosion effect of the base material.

The contents of soluble salts, including chloride and sulfate, were tested to use municipal solid-waste incinerator bottom ash (IBA) in cement-stabilized materials for roadbase. In addition, the effects of soluble salts on the strength properties of cement stabilized IBA and crushed stone mixture were analyzed by applying unconfined compressive and splitting strength tests, respectively. Moreover, the deformation properties of the mixture were analyzed by applying dry and temperature shrink tests, respectively. In addition, the microscopic mechanism of chloride and sulfate on the mixture was analyzed by using micro-test methods. Results show that the average contents of chloride and sulfate in IBA are 0.57% and 1.01%, respectively. The strength of the mixture that contains 30% IBA greatly decreases when the contents of chloride and sulfate in IBA are higher than 1.67% and 2.00%, respectively. The dry and temperature shrinkage deformations of the mixture greatly increase when the contents of chloride and sulfate are higher than 0.67% and 1.00%, respectively. Water treatment reduces the soluble salt content of IBA. Unlike the control mixture, the strength properties of the mixture that contained IBA with water treatment shows no remarkable difference, whereas the short and temperature shrinkage deformations increase and decrease, respectively. Microscopic analysis shows that Cl^- reacts with cement hydration products to produce Friedel salts, and the amount of hydration products increases in the mixture due to the addition of chloride and sulfate. However, some cement particles are not hydrated when the Na₂SO₄ content is 1.0%. The content of soluble salts in IBA should be limited to ensure the performance of the mixture.

The dynamic elasticity modulus and critical dynamic stress of improved soil under different confining pressures and frequencies are investigated by using GDS dynamic triaxial test system to examine the dynamic characteristics of cinder-improved soil as subgrade under medium and low confining pressure. The attenuation model of the dynamic elastic modulus was established to analyze the influence of different confining pressures and loading frequencies on the dynamic modulus. A fuzzy linear regression model based on structural element method was used according to the uncertainty of critical dynamic stress. Results show that the dynamic elastic modulus of soil decreases exponentially with the increase of loading times. The attenuation model can reflect the influence of frequency and confining pressure on the dynamic modulus of elasticity. The critical dynamic stress of soil is negatively correlated with the frequency of loading and is positively correlated with the confining pressure. The fuzzy linear regression model based on the structural element method can reflect the relationship between the critical dynamic stress and the frequency and confining pressure.

The interlayer mechanical properties of composite asphalt pavement structure based on the base surface morphology of a concrete surface, adhesive layer material, working environment, and other factors are complex. As discussed, the field of mass production samples, combined with laboratory shear tests, confirms the rationality of shear test in the composite interlayer shear strength evaluation, presents the composite shear strength test method of the interlayer and corrected maximum interlaminar shear strength calculation formula, further introduces the evaluation method of anti-shear strength of composite pavement, and verifies the feasibility of the method based on the results that should be used for the project compared with the surface by sandblasting and chiseling treatment, adhesive layer material, working temperature, molding method, loading method, degree of pollution, and other factors on the interface shear strength of the adhesive layer. Results indicate that the surface roughness, temperature, test factors of molding methods, loading rate, and interlayer contamination strongly influence the bonding performance between layers and in the construction of the best texture depth value and maximum shear strength between layers. The best interface texture depth is decided by the factor waterproof bonding layer type, interface roughness method, and base geometry node of the base surface. The shear performance of SBS asphalt Synchronous Crushed Stone Seal Coat interlayer sensitivity to temperature is greater than that of polymer reaction-type waterproof adhesive material. The maximum shear strength calculation formula was introduced in the special road section and temperature correction coefficient. The interlayer temperature is 40℃ when the shear strength between layers is the main control index. The calculation results and evaluation index of consistency, shear-stress test method, and system method interlaminar shear strength evaluation can be used for pavement structure design and performance evaluation.

A new type of bridge deck structure with prestressed Carbon Fiber Reinforced Plastic Reinforced (CFRP) tendons was designed. Flexural performance tests on the prestressed concrete bridge deck with CFRP tendons were conducted. The cracking and ultimate loads of such bridge deck and the stress states and failure modes of the CFRP tendons were systematically analyzed. Results showed that the bending force process of unbonded prestressed CFRP tendon bridge deck with ordinary steel bars in the tension zone can be divided into three stages, namely, initial elastic loading state, elastic-plastic stage from the appearance of cracks to ordinary steel yielding in the tensile area, and rapid deformation development and destruction stage during tension bearing of the CFRP tendons. The failure modes of unbonded prestressed CFRP tendon bridge deck were caused by the rapid deformation development due to the low modulus of CFRP tendons, and the extension of cracks and crushing failure of concrete were due to the decreased area of effective compressive concrete. The fractures were mostly equidistant parallel cracks. The cracks slowly developed in the early stage, whereas they rapidly developed after ordinary steel yielding.

A block road network based on urban spatial dimension was constructed to address the problems caused by increasing closed units that restrain the urban economy of a city and limit public resources and to implement a block system. Subsequently, a suitable size of block opening was determined by conducting a network reliability analysis on the block network. From the perspective of network reliability, the limitations of traditional network entropy were analyzed in the research on block road network reliability. Maximum flow entropy and shortest path entropies based on network entropy theory were introduced from the perspectives of directed and undirected road networks, the calculation method of maximum flow entropy and shortest path entropy of the block road network was provided, and a reliability rating criterion for the road network was established. The maximum flow and shortest path entropies in the block opening process were calculated under different block opening phases. Then, the reliability of each road network was determined based on the reliability criterion of road network, which is used as the basis for determining the suitable size of the block opening. An empirical analysis was conducted based on a residential area named Zhongxuanliyuan in Shanghai. The residential area networks were established from the nodes classified based on residents' life, leisure, travel, and others. The networks were divided into three stages based on the opening process, the shortest path entropy of each road network was calculated, and the suitable size of the block opening was analyzed and established. Results showed that the calculation of maximum flow and shortest path entropies can effectively determine the high-risk nodes of the block road network, and the network reliability has more advantages than the traditional network entropy. The network reliability determines the suitable size of the block opening based on the standard of block road network reliability, provides the basis for the phased block opening, and proposes new concepts and methods in conducting block system reconstruction.

To alleviate regional traffic congestion in large areas of the urban zonal road network, an extensible perimeter control strategy based on the macroscopic fundamental diagram is proposed to improve the effectiveness of the entire urban network. The proposed strategy considers the fleet storage capacity of the links, avoids over queuing, and establishes a constraint of perimeter control and a regional feedback control model. A new extended boundary is formed by dynamically adjusting the control boundary of the protected area in real time, and a feedback gate is set at the junction of extended boundary to restrict the traffic flow in the road network of the congested area. To verify the effectiveness of the proposed strategy, a Sioux Falls test network is used as the research area, and the effect of the proposed strategy is evaluated in Vissim. Simulation results show that the implementation of the scalable perimeter control strategy improves the operation index of the road network, and a wide range of congestion is obviously alleviated.

Continuous flow intersection (CFI) is one of the most important unconventional intersection design (UID) modes. This kind of intersection transfers left-turn movements to secondary intersections to obtain a 2-phase signal control scheme at main intersection, so the traffic efficiency at main intersection is greatly improved. To further exploit the traffic efficiency of continuous flow intersection, the coordination of main and secondary intersection signals is theoretically studied, and an optimal timing model for general use is proposed. The optimal timing model can effectively coordinate primary and secondary intersection signal timings and produce the most effective signal timing schemes for main and secondary intersections to great extent reduce vehicle delay and improve intersection capacity, and can ensure reliable operation of primary and secondary intersections in practical application. Based on the delay compositions and their characteristics of CFI, the delay and queue process evolution with the signal offset of main and secondary intersections and the corresponding scene are analysed. Then, the method for solving optimal offset between main and secondary intersections is given by optimal analysis to simplify the solving procedure of the model. In the end, an arterial intersection in Nanchang is studied as a case of how to apply the CFI channelization design to a conventional intersection and how to apply the optimal timing model to generate the coordinate timing scheme, and the micro traffic simulation is used to evaluate the traffic benefit. The result shows that (1) the optimal timing scheme can effectively reduce delays and queues and improve the intersection capacity; (2) the model calculation agrees well with the simulation result, which proves that the signal timing model is effective and accurate.

Drivers often perform lane-changing behavior for driving benefits on a broken road. Accordingly, a lane-changing model for two-lane traffic under pavement damage conditions was established based on the cellular automata NaSch model by introducing slow start and new lane-changing rules. To simulate the characteristics of a driver, traffic flow, and lane change under different road conditions, a simulation process was established in four steps, namely, lane-changing demand, lane selection, clearance detection, and lane change execution. Road damage level is classified from the perspective of vehicle operation. Vehicle driving benefit is calculated through utility theory to establish a lane selection model. A lane-changing coefficient is also introduced to study the effect of pavement damage on vehicle operating characteristics. The driver is divided into four categories based on the differences among drivers' behavior, namely, adventurous, alert, cautious, and slow. The characteristics of the different types of drivers under pavement damage conditions were analyzed by setting simulation parameters. Results showed that the lane-changing coefficient would increase with the increase of pavement damage level. A high level of damage would result in a low benefit of the vehicle traveling on damaged roads, which further increases the probability of lane change that can properly simulate the effect of pavement damage on vehicle lane-changing behavior. The highest lane-changing rate was obtained by the adventurous driver in medium density, and the speed variance and lane-changing rate gradually increases with the increase of damage level. The high lane-changing rate also indicates that pavement distress aggravates lane-changing behavior and interferes with the normal flow of traffic operation, thereby providing a theoretical basis for strengthening traffic safety management of damaged road sections.

Coordination control is implemented on the main public transport system to reduce delay and improve the operation efficiency of buses on urban arterial roadways. First, the concept of a dual-loop phase is introduced and a new phase structure and sequences are proposed. Then, optimization models of the common signal cycle and effective green light time are built. Second, a genetic algorithm is used to optimize signal offset in coordination control according to the driving characteristics of a bus. To evaluate the effect of coordination control, a delay function is established to describe the control effect according to theory of triangle delay. Finally, the main arterial road is selected for a case study. The main parameters, such as common signal cycle, effective green light time, and offset, are optimized using Lingo and MATLAB. Results show that the bus delay value tends to decline after implementing the algorithm and the 50th iterative optimization result is 20.13% lower than that of the first iteration.

A QC/T51-2006 standard country five-series road-sweeping vehicle is used as research object to improve the mechanization and work efficiency of a road sweeper and reduce the degree of environmental pollution. This study examines the flow of the fluid in an air duct of the sweeper during the working process and identifies the limitations of the original fan structure design. The sweeping air duct and structure are of optimized design. In accordance with considerable analyses and research, fluid simulation of the original air duct was conducted using the finite element analysis software NX Nastran. A turbulence model is used to simulate the gas field inside the duct, ignoring the influence of temperature on the gas and wind pressure loss caused by a high-speed rotation of the fan. The entire duct was divided into two parts, namely, entrance and exhausted air ducts. In the model transfer process, the original assembly hole and welding plate were removed, and the unnecessary fillet and protruding structure were optimized. This approach was conducted to obtain the accurate value of wind speed in the suction port and outlet, which was compared with the starting velocity of dust particles and suspension speed. The flow field and streamline, velocity vector, and static pressure distribution of the original sweeper were obtained. Results show that through the data simulation analysis, the original sweater fan duct structure was optimized and its design was enhanced. This result increases the air duct speed by 50%. The fan power is reduced by 20 kW, thereby enhancing its efficiency. The energy saving is approximately 36.6%. The results provide data support and theoretical basis for the optimal design of the duct and structure. Furthermore, the results present theoretical and methodological support for the development of a new road sweeper.

The relationship between subjective and objective evaluations on the steering performance of passenger vehicles is investigated to realize the subjective evaluation with objective measurement and to completely replace the objective measurement by subjective evaluation. The subjective evaluation uses steering performance as the study point, and objective evaluation focuses on angle pulse, wheel, snaking, and central tests. The subjective and objective evaluation systems are established, which consist of 7 subjective evaluation indicators (inherent steering characteristics, steering transient response, yawing response, and others) and 17 objective evaluation indicators (formant frequency, average steering angle, yaw velocity gain, et al.). A total of 7 groups of subjective evaluation score and 17 groups of objective evaluation score are obtained by evaluating 4 vehicles. The functional relationship between subjective and objective evaluations is established through regression analysis. Result shows that a 1D binary linear relationship exists between subjective and objective evaluation indicators under a small sample condition. Most of the subjective evaluation indicators have a negative relationship with formant level within the linear function. The formant level is a critical indicator that influences the steering performance of passenger vehicles on the basis of hypothesis testing and dynamic analysis. The lower the formant level is, the higher the subjective evaluation score will be.

This study elaborates the evolution and feature of highway freight volume statistics and calculation methods to study the main problem of the 2014 new trial scheme. On the basis of the analysis of statistical methods and features of highway freight volume statistics trial scheme, the problem of a stratified sampling method of vehicles was discovered. A grey relational analysis model was established by using Excel software. The high degree of correlation indicators and highway freight volume were determined by grey relational analysis model. Results show that product yield and freight vehicle sales and tonnage have a high degree of correlation with highway freight volume. This indicator can be used to evaluate the rationality of the freight traffic trend on the highway. On the basis of problem analysis, a new idea is proposed to improve highway traffic volume. Then, a model is created with EViews6 to conduct calculation. Iron, cement, paper and paperboard, and truck tonnage were selected to establish that the regression model has high fitting degree with the sample data. Meanwhile, the standard error is smaller and can be used in calculating highway freight volume. Therefore, an analysis of a new highway freight volume statistics trial scheme will provide an academic basis for the assessment and improvement of highway freight volume statistics and calculation method, respectively.