In recent years there has been an increased number of cases where geogrid have been incorporated into unbound road base layers to promote roadway optimization. The term optimization in this context refers to the use of geogrid to form a mechanically stabilized base course layer which leads to an improved performance of unbound layers by controlling particle movement and reducing permanent deformations. A mechanistic based pavement design approach offers a better means to accommodate the geogrid effect within the pavement structure. Guidance published by AASHTO recommends that pavement designs incorporating the effect of a geosynthetic need to be based upon experimentally derived input parameters. Performance data obtained from full scale accelerated pavement test studies and monitored field trials can be used to determine the influence of a geogrid on performance over the life of the pavement. This paper will highlight the concept of pavement optimization and present several cases where both post construction and long term evaluation methods were utilized in the quantification of the effectiveness of geogrid stabilized pavement structures.

When there is a significant stripping in asphalt pavement, it is common practice to use a hydrated lime (HL) as an anti-stripping additive (ASA). However, since many asphalt plants do not have facilities for weighing and casting HL, they prefer to use of a liquid-type ASA (LA). Therefore, various brands of LAs which show proper anti-stripping function are currently developed, imported, and marketed in Korea. In addition to the anti-stripping effect, the HL has been known to give a significant age-retarding effect on paved asphalt in the field. Therefore, there was a question about whether or not the LA provides the same anti-aging effect as The HL. This study investigated anti-aging effect of the asphalt mixes which were prepared using both ASAs and short-term aged and long-term aged in the laboratory. The absolute viscosity was measured as an aging index from the binder recovered from the mixes after short-term aging (STA) and long-term aging (LTA) processes. The results showed that there was a significant higher aging found from the LA-added mix than the normal mix without any ASA. On the other hands, the mix with HL showed significantly lower ageing level than the LA-added mix and normal mix. The retardation of age-hardening by using HL was more effectively observed when the STA condition was stronger.

The aged asphalt binder included in RAP due to the oxidative aging, repeated vehicle load, climate process affects to the recycled asphalt mixture property and performance (stripping, port hole and premature cracking initiation) after paving. The rejuvenator commonly is used to recover the aged binder in hot mix asphalt (HMA) containing RAP; the effect of rejuvenator in HMA had been proven according to many studies for over the past several decades. Also, there are many methods for using RAP in asphalt mixture in aspects of HMA, cold asphalt mixture (CMA) and worm mix asphalt mixture (WMA), and a foamed asphalt mixture is one of them. Employing the foamed asphalt manufacturing technology, the content of RAP in recycled asphalt mixture can be increased more. The objectives of this study are to evaluate of rejuvenator influence on foamed asphalt mixture using 100% RAP based on strength change of test sample and stiffness change of recovered binder from RAP and specimen. As the results, when rejuvenator was added to make foamed asphalt mixture, MS and ITS values decreased clearly as compared with the foamed asphalt mixture without rejuvenator use. The use of rejuvenator up to 6% showed a tendency of the decrease of strength and stability remarkably. The use of rejuvenator over 6% did not decrease the strength and stability. DSR test results, the use of rejuvenator in making a foamed asphalt mixture using 100% RAP showed a recovery effect of the foamed asphalt mixture. And recovered binder from the specimen that was made adding the 6, 12 and 18% rejuvenator showed lower stiffness obviously compared to the recovered binder from RAP adding same dosage of rejuvenator.

The main objective of this research study is the performance evaluation of 40/50 and 60/70 binder for asphalt mixtures in Vietnam. To accomplish the objective of this research, a dense gradation with nominal maximum aggregate size of 19.0mm is used for the asphalt mixtures. Marshall Stability (MS) test, Tensile Strength Ratio (TSR) test, Wheel Tracking (WT) test, and Dynamic modulus test are conducted to evaluate the rutting and cracking performance of 40/50 and 60/70 binder in asphalt mixtures. It was found that the Marshall stability of asphalt mixtures using 40/50 binder is about 12% higher than asphalt mixtures using 60/70 binder while the rutting resistance of the mixtures with 40/50 binder shows 2.5 times higher than 60/70 binder at 15,000 load cycles. Moreover, the TSR of asphalt concrete using 40/50 binder and 60/70 binder are approximately 95% and 79%, respectively which means that using 40/50 binder is very good for moisture damage resistance. Finally, the dynamic modulus test was done at a reference temperature of 20oC and frequency of 1,0Hz. The dynamic modulus of asphalt mixture with 40/50 binder is about 6257 MPa, which is two times higher than asphalt mixture using 60/70 binder. Based on the results of this study, it can be concluded that asphalt mixtures using 40/50 binder can improve the rutting and moisture damage resistance of asphalt concrete under high temperatures and moisture conditions significantly. It is noted that these conclusions were based on only on a limited number of samples and conditions. Further studies must be conducted to investigate the effect of 40/50 binder on fatigue cracking of asphalt pavement in the field.

In this study, several approaches in evaluating moisture sensitivity of asphalt mixtures were investigated and compared. To evaluate the moisture damage resistance, twenty types of asphalt mixtures with and without anti stripping additives were tested in the laboratory. Uniaxial compressive strength (UCS) and indirect tensile (IDT) testing were performed to determine the Tensile Strength Ratio (TSR) and Cohesion Strength Ratio (CSR). Stone Mastic Asphalt (SMA) mixtures were found to provide good moisture damage resistance compared to other mixtures. It also does not require anti stripping additives to improve its moisture resistance. Moreover, the correlation coefficient between the TSR test and CSR tests is 0.99 with an average error of 1.5%, which indicates that the TSR test following AASHTO T-283 is still the most reasonable criteria in evaluating the moisture damage of AC mixtures. Marshall Stability Ratio (MSR) and Marshall Stability to Flow Ratio (MSFR) were conducted and were compared to TSR test results. It was found that MSFR value may be used to evaluate the moisture damage resistance of AC mixtures instead of TSR test. Finally, Dynamic Immersion (DI) test was performed to evaluate moisture resistance for loose asphalt mixtures. The DI results showed good correlation also when evaluating moisture resistance compared to TSR. When using DI testing in evaluating moisture resistance, it is recommended to test after 48 hours since it showed higher correlation with the TSR values. Further study is recommended to improve current testing evaluating moisture susceptibility of asphalt mixtures to properly associate it with TSR values.

Low temperature cracking on asphalt material is one of the serious distresses for asphalt pavement built in northern U.S., Europe and Canada. Thermal stress is a key factor for measuring (and estimating) the resistant capability of asphalt pavement against low temperature cracking. For this reason, many road agencies have recognized thermal stress as a crucial parameter for evaluating the low temperature performance of asphalt pavement materials. Thermal stress is conventionally computed through two steps. First, the relaxation modulus E(t) is generated thorough the conversion of the experimental creep compliance data D(t). Then thermal stress (T℃) is numerically estimated solving convolution integral. In this paper, a one-step approach to the calculation of thermal stress is proposed. This method is based on Laplace transformation. Thermal stress and corresponding critical cracking temperature obtained with single- and double-step procedure on a set of three mixtures are graphically and statistically compared. It is observed that the application of Laplace transformation provides reliable computation results of thermal stress compared to the conventional computation approach.

Road network in the Mekong Delta is mostly coastal and river routes, then they are often flooded when the floods come in. As a result, the foundation and pavement are destroyed, reduced life expectancy, resulting in unsafety in traffic, cost of maintenance and repairs…. This paper establishes the technical conditions for the calculation on the flexible pavement working in the wet conditions (so flooded) based on the maximum usage of available materials in the provinces in the Mekong Delta. Simultaneously, we propose the flooded flexible pavement under the current climate change conditions.

Recently in Construction field, It has been the big issues to produce an Eco-friendly Construction material and to solve problems about the First grade–Aggregates’ supply&demand. While the Eco-friendly Construction materials which are refurbished and reproduced from construction wastes and industrial by-products have a great deal of effectiveness such as cost or CO2 emission reduction, there is an additional logistical cost due to go through with some processes for recycle such as Intermediary treatments or management and collection of materials. Furthermore, Demand of the First grade-Aggregates is rising and spreading all over the nation for the improvement of Road driving performance, But there is also an additional logistical cost for supply&demand due to the cost of transport growth by sites of construction. In this study, the process and methodology of the new material supply and demand route routings using the Arc Gis Program and the calculation of the available distance through economic analysis are presented. After examining the cost status of construction materials and logistics costs by examining the literature review and related industry, economic feasibility was obtained by comparing the price of general construction materials with the total cost of comparable materials and logistics costs. After an economic analysis, ArcGis3.0 was used to visualize the materials’ supply&demand route and As a result, We can observe the economically secured route from the construction materials’ production plant to where the domestic transportable route and nodes mapped. Throughout the study, the pre-groundwork for an efficient use of the construction materials is able to be prepared and It will be helpful to invigorate supply&demand. In addition to the economic analysis in the future, If the real-time traffic information (traffic volume, speed, environment, etc.) and the performance (structure, functionality, etc.) of each construction materials are reflected, It will be possible to build a decision system for selecting construction materials which meet consumers’ various needs.

The objective of this study is to find a way to enhance winter traffic safety. This study has four main contents as follows. Firstly, the characteristic of winter traffic during the snowfall was examined in terms of traffic capacity, travel speed and standard deviation of travel speed. Next, the winter culture including prerequisites for driving and driving skills as well as the standard for snow removal were reviewed. Then, the cases of traffic management in UK, Germany and Japan were reviewed. Finally, the countermeasures to enhance the traffic safety were examined. After that, the variable sectional enforcement for speeding was proposed as a countermeasure to enhance traffic safety by reducing severe travel speed variation. The criteria for the operation of the variable sectional enforcement for speeding were set from 20% to 50% reduction of speed, depending on the amount of snowfall. The sections in which the accidents happened often during the snowfall were considered as the locations to implement the variable sectional enforcement for speeding.

Hard Shoulder Running is one of the ways to handle road traffic by installing LCS signals on the shoulder, making use of the shoulder as a straight road during rush hour, and thereby increasing the capacity of the road in the short term. Since it was first introduced on Youngdong Expressway in September 2007, it has been implemented in 32 highway sections and has improved the speed of traffic. The Seoul-Chuncheon Expressway, which is a private investment toll road, introduced Hard Shoulder Running only for some sections in 2014, but due to the geomorphic characteristics of the lanes with many tunnel sections, It did not perform the function of Hard Shoulder Running. Therefore, they are considering expanding the tunnel section of Hard Shoulder Running, and it is necessary to examine the safety of the tunnel part to implement this. The purpose of this study is to investigate the effect of the change of geometry, such as reduction of lane width in tunnels, and the installation of various guiding facilities, on the safety of tunnels by applying a driving simulator. Virtual reality data were constructed at 3.25m and 3.0m respectively in the tunnel section of the Seongjong Tunnel of Seoul-Chuncheon Expressway and Geumnam Tunnel to determine the feasibility of Hard Shoulder Running and appropriate speed and lane width. EEG was used for analysis. The test subjects were 15 young drivers / 15 old drivers. Analysis items were classified into four categories: driving speed, steering wheel operation, lateral placement of vehicle, and driver's psychological factors. As a result of analysis of the experimental results, it was confirmed that the allowance width of outer wall and m of tunnels was secured, and the lane width of 3.0 m was stable in terms of driver driving behavior, and operation speed was lower than 50 km/h.

In recent, a lot of fatal crashes with serious damage in terms of fatality and cost have been occurred in tunnel areas of expressways, drawing a huge social concern. However, each countermeasure for the tunnels in which traffic accidents have been happened is different, and it doesn’t seem that it is a fundamental measure because there is no unified standard. This research aims the application of standardized and comprehensive countermeasures for the improvement of traffic flow condition and safety in tunnel areas, through the cooperation with the organizations which are in charge of traffic safety management in Tunnel areas on expressways. The main components are as follows; the first, the establishment of comprehensive countermeasures providing tunnel areas with more safe traveling environment, the second, the standardization of comprehensive countermeasures, the third, the cooperation with the organizations in charging of traffic safety for the establishment of a detailed plan.

Kathmandu is the capital city of Himalayan country Nepal. It is a bowl shaped small valley with 3.5 Million populations. With approximately 5000 lane- km of roads and about 40% of entire vehicle populations of the country plying here without any grade separation, it has become quite challenging to manage the smooth flow of traffic in the city. The population of motor bikes is 75% making the job of traffic management difficult. Lack of foot path and bi cycle lanes for pedestrians and NMT and the narrow streets with manually controlled traffic intersections further complicate the deteriorating traffic flow. The improvement efforts including widening of critical roads could produce short term results only. A project named Kathmandu valley Sustainable Urban Transport Project, KSUTP funded by ADB could not progress as desired. This paper discusses the problems, studies and measures being undertaken to resolve these issues.

In this study, eye movements of drivers on expressway ramps were comprehensively investigated using raw data from driving simulator and eye tracker(MyGaze) deducted though the previous study. Based on the literature review, several parameters including number of fixations, fixation time, horizontal & vertical eye movements, and gaze position were selected. With them, eye movements of older drivers and young drivers were compared and investigated. Average fixation time of older drivers is shorter and tend to focus more on the inside road edge for both left and right turning ramps comparing young drivers. Also, they tend to look wider at right turning ramp. All driver’s fixation points were spread along the inside road edge for both left and right turning ramps. Currently, road delineating facilities are installed on the side where centrifugal force is applied. However, considering the result, it should be installed where centripetal force is applied. In addition, road line marking management should be more taken care of. For future study, vehicle’s speed is also in need of consideration with eye movement.

Highly developed, European industrial countries normally have a dense network of rural highways. The future focus of roadwork in Germany, where there is a high density of 1.6 km of rural highway per km² of land, will involve upgrading and rebuilding rural highways prone to accidents. As new guidelines are not completely relevant for upgrading existing highways and exceptional permits are often required, there is an increasing need to use simulation in the design process to assess discrepancies from the standards and their effect on traffic safety. Using virtual driving (automatically using a defined driver profile or a driving simulator), it is possible to objectively assess expected driving behaviour using characteristic feature graphs and quantitative parameters derived from them. Zwickau University of Applied Sciences has developed a new multi-stage methodology for upgrading rural highways by using a 3D design working place simulator. The highway is automatically retraced using survey data and genetic algorithms in stage 1 (preliminary review) and is broken down into the horizontal and vertical projection design elements. Stage 2 involves determining the shortcomings on the road by superimposing the design elements, the actual accident figures and virtual driving runs. The actual replanning work occurs in stage 3, taking into account the minimum and maximum standard figures for the design elements. The replanning work is feasible, even if the standard figures are not met along parts of the route, but the graph figures, parameters and virtual driving runs prove that there is no reduction in traffic safety. Otherwise, the route needs to be realigned. After finishing the testing period of the hard- and software components, the methodology and the working place can be used from designing engineers for the preparing process of practical projects.

Outsourcing allows companies to entrust to an external actor the management of part of their activities, particularly for peripheral processes to improve its performance. Outsourcing, in its strategic and global perception, can also be a support lever of activities related primary processes in a framework of partnership, facilitated by a process of innovation and promoting sustainable development especially in the area public. This is what this thesis seeks to demonstrate using a qualitative assessment of the main organizations responsible for the management of transport infrastructure in Morocco (Morocco's National Society of highways, roads department, National Agency of ports, National office of Airports and National Office of railway). This research adopted a recursive, abductive and inductive approach to first validate the theoretical corpus mobilized, and then design the analysis model of the empirical field and finally build the modeling of the proposed outsourcing oriented strategic partnership, innovation and sustainable development. The main components of this model are PARI model which considers the choice of partner the key to innovation, the structural model which distinguishes four levels (Corporate, Strategic business unit, Strategic Outsourcing, Sales Force) and management style model for every organizational level which is based on leadership, innovation and sustainable development. The appropriation of this modeling by public organizations will allow them the animation of the proposed economic model to make it an engine of entrepreneurship and unemployment resorption.

The Golden Gate Bridge, known as one of the most beautiful bridges in the world, serves 110,000 vehicles per day, connecting San Francisco to inland as a segment of Highway 101 in California. The average peak hour volume over 6,500 vehicles per hour exceeds the traffic capacity of three lanes on each direction. Due to unique function of the bridge as a gateway of San Francisco, the peak directions in the morning and afternoon were explicitly distinguished. Recurrent traffic delay on the peak direction deteriorated level of service during the commute periods and caused user’s inconvenience and traffic accidents. The workers previously used to move plastic delineators to change lane configuration (4-2, 3-3, and 2-4) in several times a day. Neither did it provide prevention nor physical protection from the head-on collision on the bridge section. In January 2015, the Golden Gate Bridge was completely closed for two days to install the moveable median barrier (MMB) system, Road Zipper®, for more effective and safer variable lane management than the previous operation. One-meter section with 30.48 cm wide of highly reinforced concrete barriers are linked to form a continuous barrier wall and the machine lifts and passes the barriers through a conveyor system at a seeds up to 16 km/h. The MMB enables to quickly reverse lane configuration without traffic closure, providing more lanes to the peak direction as well as eliminating head-on collision on the bridge deck by presence of a physical structure. The traffic monitoring study result shows the significant improvement of average speed during peak hours and the regional traffic accident records shows improvement of safety after implementing the MMB on the Golden Gate Bridge. According to the traffic accident records, 13 injuries occurred in five accidents of vehicle collision in two-directions from 2007 to 2014 but no two-way accident has been reported since the operation of the Road Zipper® began. Furthermore, the MMB would be effectively implemented on construction work zones, managed lanes, variable lane management and other traffic operation to improve traffic safety and maximize utilization of roadway facilities.

Autonomous Driving (AV) is expected to reduce the traffic accidents. Highways again need to be changed to afford AV, so the benefits we expect from introducing AV can be much larger. Highways which are easy to drive for humans is also easy to AV. Building or changing the highways in the way that they are good at explaining the way how to drive can be the very first step to afford AV. Highways which have the fail-safe features can be the second step to afford AV regardless of the weather is good or bad. Highways which have an ability of good communication with the vehicles, so drivers avoid the hazards, can be the third step to afford AV.

As the transportation sector accounts for approx. 30% of energy consumption in Germany, a gradual increase in the number of electric vehicles (1 million should be operating by 2020) can make a significant contribution to road transportation sustainability. We need to plan and construct multi-functional infrastructure corridors to accelerate the introduction of electric vehicles. These not only include the actual transportation infrastructure, but equipment for obtaining energy (solar power units and wind turbines) and the necessary recharging systems (charging points, places and lanes). Zwickau University of Applied Sciences has conducted a feasibility study to mathematically calculate the technical design criteria and energy balance (energy requirements/output) along a section of highway, depending on the electric car quota, the section’s parameters and various energy generation scenarios; this involved driving simulation and real driving experience. The experiment results clearly show that, when designing transportation infrastructure, it makes sense to plan so-called multi-functional infrastructure corridors, which enable independent energy production, parallel energy distribution through cables and directly supplies from the recharging infrastructure. The real transportation infrastructure must develop from a simple to an intelligent roadway. The road standards must take into account the new requirements for alignment and cross-section design. Zwickau University has developed a new methodology for planning and designing multi-functional infrastructure corridors. It generates them with computer support, taking into account points of constraint. Genetic algorithms serve as the mathematical model. Pilot scheme results show that it will be possible to transfer this process to engineering offices in the near future.

Since the opening of Gyeongbu Expressway, the first Korean expressway of 428km connecting Seoul and Busan in 1970, the total length of expressway exceeds 4,200km at the moment. The Expressway Traffic Management System (ETMS) started at the Seoul-Daejeon section of Gyeongbu Expressway in 1992 and it was expanded to the whole expressway network. Although the introduction of a successful traffic management system, the total recurrent congested sections below 40kph are 51 sections of 373km on expressways and the traffic congestion cost as a social cost reaches a total of 2.8 trillion KRW (about US $2.6 billion) only on the expressways. Measures to improve traffic congestion can be applied to expanding the supply of facilities and increasing the efficiency of facilities. Physical improvement, which means expansion and construction of roads, is cost and time constrained, and there is also a limit for the improvement of traffic operation. In order to maximize the effect of traffic congestion management, there is a need to harmonize the both, but there is still a lack of awareness of the importance of integrated traffic management in Korea. In this study, the concept of Integrated Traffic Management (ITM) on expressways integrating various individual traffic management techniques such as ramp metering, toll metering, and variable speed limit is proposed and the effect of the effect of Integrated Traffic Management was carried out by the microsimulation model for 15km section on the Seoul Outer Ring Expressway.

Tunnel is the main infrastructure in transportation system especially in Gangwon province which has 90% of its area covered by mountains. Responding to the needs for evaluating the tunnel damage in this region, the temperature inside 10 tunnels, one-way and two-way, were measured in winter by using temperature sensors. The temperatures along the length of tunnel, from the entrance until the exit, were obtained from sensors placed at 2 meters above the road. The measurement results showed the distribution of the temperature along the length of the tunnels since November 2016 until March 2017. The data showed that among all the one-way tunnels, the variation of the temperature at all positions along the length of the tunnels have almost the same gradient of temperature of all months observed. There were no significant changes between the temperatures at those points along the tunnel; whereas the changes at the entrances and the exits of the tunnels were remarkable. It was also noticed that there was the different trend of temperature variation between the one-way and two-way tunnels.