Expressway Route and Interchange Design

The acceleration of urbanization has promoted the increase in the number of urban highway projects, resulting in an increase of emphasis on the quality of urban highway projects. The quality and safety of highway construction directly affects the driving comfort, safety, and service life after it is put into operation. Among them, asphalt pavement is an important structure in highway construction, and it is also a key link that directly affects the construction quality. In order to ensure the quality of construction, it is necessary to strengthen on-site testing during the construction process to discover problems in time, and to ensure that the construction is up to standard. This paper mainly presents an analysis on the necessity and application of on-site quality inspection technology for asphalt pavement construction of highway engineering, and outlines measures to improve highway engineering construction testing technology.

As the traffic accident rate keeps growing in China, more and more attentions have been paid to highway safety especially during highway design phase. This paper focuses on developing a new Highway Safety Evaluation System (HSES). First, the Highway Safety Design Model (IHSDM) software and its structure were introduced and the challenges of applying this tool to the highway design process in China were investigated. And then, the structure and data organization of HSES were introduced, furthermore, the key data transfer tool was completed, that can transfer existing highway geometric design data in China to Land XML 1.0 data for the use of after-then safety evaluation. Thirdly, the modules of HSES were shown and explained. And details of the proposed models development and implementation for operation speed and crash prediction were described. Finally, the advantages, limitations and future expectations of the software system were discussed.

This report documents the research performed under NCHRP Project 1-43. It describes the work activities undertaken in the study and presents the results of those activities toward the development of the Guide for Pavement Friction. The information provided in this report serves as the basis for many of the guidelines and recommendations contained in the Guide. The information will be of interest to highway materials, construction, pavement management, safety, design, and research engineers, as well as others concerned with the friction and related surface characteristics of highway pavements. Using information collected through detailed literature reviews and surveys/interviews with state highway agencies, this report discusses a variety of aspects regarding pavement friction. It describes and illustrates the importance of friction in highway safety, as well as the principles of friction, as defined by micro-texture and macro-texture. It identifies the factors affecting friction and examines the ways that friction can be measured (equipment and procedures) and expressed (reporting indices). Most importantly, it presents valuable information on (a) the management of friction on existing highway pavements and (b) the design of new highway surfaces with adequate friction. This information focuses on techniques for monitoring friction and crashes and determining the need for remedial action, as well as identifying combinations of aggregate (micro-texture) and mix types/surface texturing methods (macro-texture) that satisfy friction design requirements. The report includes various conclusions and recommendations based on the results of the study, and it features five appendixes containing supplemental information on friction.

The natural environment affects the construction of desert highways. Conversely, highway construction affects the natural environment and puts the ecological environment at a disadvantage. To satisfy the variety and hierarchy of desert highway construction and discover the spatio-temporal distribution of the natural environment and its effect on highway construction engineering, an assessment of the natural regional divisions of desert highways in China is carried out for the first time. Based on the general principles and method for the natural region division, the principles, method and index system for desert highway assessment is put forward by combining the desert highway construction features and the azonal differentiation law. The index system combines the dominant indicator and four auxiliary indicators. The dominant indicator is defined by the desert’s comprehensive state index and the auxiliary indicators include the sand dune height, the blown sand strength, the vegetation coverage ratio and the annual average temperature difference. First the region is divided according to the dominant indicator. Then the region boundaries are amended according to the four auxiliary indicators. Finally the natural region division map for desert highway assessment is presented. The Chinese desert highways can be divided into three sections: the east medium effect region, the middle medium-severe effect region, and the west slight-medium effect region. The natural region division map effectively paves the way for the route planning, design, construction, maintenance and ongoing management of desert highways, and further helps environmental protection.

A further generalisation of the planar cubic Bézier spiral

G2 curves composed of planar cubic and Pythagorean hodograph quintic spirals

With the fast development of the freeway construction in China and the increasing demand of the improvement of the landscape and safety in the highway system, the traditional method of the highway alignment design cannot meet the need mentioned above. A Three dimensional highway real-time visual system (3DHVS) is developed as a basic platform for the highway visual and physics simulate, which had many merit in the highway alignment, landscape and safety design by the means of fly-through, interactive and physics simulation with the virtual scene. By analyzing the disadvantage of the widely used design method, a performance and expansible architecture of 3DHVS is presented. Finally, we show the application of the system.

The fast development of highway construction makes its negative effects on the natural ecological environment more and more prominent, which makes the designer to have to think in earnest about how to deal with the relationship between highway construction and ecological environmental protection and how to put the concept of harmonious relationship between human and nature, subsistence and development, and alteration and respect of nature into highway design. Based on the analysis in ecology and ecosystem of highway, highway ecological esthetics and ecological ethic are explained in the paper. The core of the relationship between highway construction and ecological environment protection is studied from the three aspects of avoidance and compensation, destruction and recovery, and protection and utilization. The concept and characteristics of ecological highway are defined. And ecological highway design principle and requirement are also explored to confirm the key content of ecological environment protection in highway construction, which make the ecological ideas apply to the entire life circle of highway construction including plan, design, construction and operation to achieve highway sustainable development.

Distribution of uniform reliability over AADTs estimated for a new highway route

<p indent="0mm">Since the proposition of the Belt and Road Initiative, China’s overseas highway projects have developed rapidly. As the leading carrier for the construction of other projects, highway construction is vital to the construction of other supporting facilities, and at the same time it can stimulate economic growth in the regions along the Belt and Road and narrow the development gap between them. However, presently there are few statistics on China’s overseas highway projects, and there is a lack of datasets on overseas highway projects. This dataset uses web crawler technology, various corporate official website consultation reports, OSM (open street map) and DIVA-GIS road data sources to collect information on 99 highway projects in 51 countries, including 14 items of basic information such as the project location and construction of highway projects, start time, route length, construction unit and cooperation mode. The collection of road information not only is conducive to enterprises to strengthen communication, formulate more international norms, rationally carry out investment in overseas highway projects, but also has positive significance for the overall planning and layout of China’s overseas highway engineering projects.

Informatization and intelligence are the development trends of the future highway asphalt pavement construction quality process control. This paper starts with the principle of asphalt pavement management and control technology, and verifies the application effect of information technology in the early warning and disposal of asphalt pavement construction quality. At the same time, this paper realizes the online control and management of highway construction quality by collecting the raw material processing, mixing and transportation information of asphalt mixture, and monitoring the construction links such as pavement paving and compaction in real time. Finally, the analysis is carried out in combination with engineering examples. The research results can provide reference for other engineering practices.

Safety has always been an important component in the planning, design, and operation of highways. A framework for highway safety mitigation is outlined in this paper that provides a logical and comprehensive context within which efforts to improve highway safety can be made. This framework incorporates predictive methods of highway safety analysis to allow transportation officials to proactively improve the safety of the transportation system. This framework has been developed around the Roadway Safety Management Process contained in the Highway Safety Manual (HSM) and has six primary steps: 1) Network Screening, 2) Diagnosis, 3) Countermeasure Selection, 4) Economic Appraisal, 5) Project Prioritization, and 6) Effectiveness Evaluation. In addition to methods used in the HSM, alternative methods of predictive highway safety analysis are discussed in context of their application. This framework for safety mitigation can be applicable to transportation agencies worldwide to maximize benefits resulting from highway safety investment.

Highways are one of the main structures of cities in the field of economic, social, and environmental facilities that connect cities, regions, and people each other. Determining the suitable highway routes includes difficult and complex processes due to the construction costs. Additionally, priorities, expectations, and constraints for economic, social, and environmental parameters must be considered together to provide efficient solutions to requirements. Multi Criteria Decision Analysis (MCDA) techniques such as Analytical Hierarchy Process (AHP), Ideal Solution Similarity Selection Ranking Technique (TOPSIS), and Vise Kriterijumska Optimizacija I Kompromisno Resenje (VIKOR) and Least Cost Path Algorithm (LCPA) with Geographical Information Systems (GIS) combination are the most suitable way to overcome these complexities. In this study, slope, aspect, geology, elevation, distances to roads, settlements, water bodies, fault lines, buildings, natural disasters, protected sites, population, and land use were selected to determine most suitable highway construction areas and route. The AHP, TOPSIS, and VIKOR methods were applied to calculate cost surfaces for least cost paths generation with LCPA, and the generated three routes were compared. As a result of the comparisons VIKOR route was the most suitable route considering the topographical statistics and all the three methods consistent with each other and current road.

A project quality assurance organization (QAO) assigns project quality responsibilities and relationships, both for design and construction. In the highway sector, all project quality roles and responsibilities have historically been assigned to the state highway agency (SHA), an accepted and well-understood industry practice. However, increasing use of alternative project delivery methods and reductions in SHA staffing are having an impact on traditional QAO practices. SHAs are increasingly selecting alternative QAOs, but they are making these selections in an ad hoc manner because of limited staff knowledge and experience, and a lack of guidance from the research community. Highway design and construction quality research focuses almost exclusively on inspections, observations, corporate quality, warranties, and materials testing, resulting in a gap in the research about shifts in project quality roles and responsibilities. This research extends the civil engineering quality management body of knowledge by identifying factors that influence the selection of QAOs and rating the appropriateness of the QAOs for each selection factor. Because of the complexity of the topic, scope of the decision process, and the limited project data available, structured interviews and the Delphi method were chosen to explore the selection factors. The research discovered 10 factors: project size, project complexity, project delivery method, project schedule sensitivity, availability of agency project staff, agency project staff experience, agency culture, industry ability to manage their own quality, trust between agency and industry, and amount of quality risk to shift away from the agency. The research provides the highway industry with new understanding of the effects that each selection factor has on the fundamental QAOs. This fundamental knowledge will allow SHAs to make more informed QAO selections.

In recent years, with the extending highway construction scale in mountain areas, there is lack of traffic safety facilities in some mountain areas. The problems of unreasonable and irregular traffic guarantee engineering construction stand out. Especially in rural highway in mountain areas with complex topography, the traffic accident rates are increasing, causing lots of dead and economic losses. Studying deeply on rural highway traffic safety problems in mountain areas and improving rural highway traffic safety level are the problems that we need to solve urgently. This essay analyzes the law of rural highway traffic accidents in mountain areas and makes a conclusion that the existing problems in rural highway safety managements in mountain areas at present. Based on this, this essay analyzes systematically the influent factors of rural highway traffic safety and a conclusion can be drew that the frequent rural highway traffic accidents in mountain areas not only are caused by bad line type for roads and no security arrangements are set. At last, based on macro-management level, it proposes a series of positive highway safety management countermeasures including strengthening traffic safety education, establishing traffic safety management system, improving passenger transport policy and management system, formulating dangerous sections inspection mechanisms.