As mentioned at the Davos World Economic Forum in 2016, there is now a worldwide wave of waves of the Fourth Industrial Revolution. The flow of government policy and R & D research is also focused on fostering industries based on the Fourth Industrial Revolution. Research in the field of geotechnical engineering can also be a research that lags behind trends if it is not merged with the technology related to the fourth industrial revolution in the future. Therefore, this study analyzed the applicability of the fourth industrial revolution technology in the field of expressway maintenance.

Recently, maintenance science has been promoted and many advanced equipments have been developed such as GPR surveying, automatic gauging robot, bridge deck inspection robot. And the government - led policy on the fourth industrial revolution affects the R & D field of science and technology, and science for all fields remains a challenge. However, the equipment that has been developed so far is applied separately to each field, so that it is not possible to grasp the state of the entire structure. Therefore, in this study, the applicability of BIM and image information mapping technology in expressway maintenance was analyzed. To accomplish this, a basic analysis was conducted to identify the characteristics of the equipment developed for the current structure inspection and to build a platform to manage the collected data collectively.

In Korea, a vehicle overtaking is prohibited by the law in tunnel and bridge sections where a road section has lanes with solid line. However, this regulation has some problems in terms of traffic operation and safety. So, it is necessary to find a way to improve the lane operation in tunnel and bridge sections. The objective of this research is to propose a systematical logic and specific standards to draw up an improvement of lane operation in tunnel and bridge sections on expressways. For that purpose, the status of lane operation in tunnel and bridge sections on both of the domestic and the abroad expressways and the improvement effect of the lane management were analyzed and, followed by it, the ways to improve lane management were suggested. In the comparison of the number of traffic accidents between road sections and tunnel sections, it was resulted that the number of traffic accidents per unit length (1km) of tunnel sections was lower than that of road sections. In addition, in the comparison of the fatality of traffic accidents, the fatality of tunnel sections on expressways was lower than that of other road tunnel sections. Through the analysis, it was resulted that there was a low correlation between the permission of the lane change in tunnel sections and the increase of traffic accidents. Moreover, in the comparing the traffic accidents between expressway tunnels and other road tunnels as well as between road sections and tunnel sections on expressways, there was no significant difference in safety between the solid line sections and the dotted sections. As a result of the analysis on the pilot operation section, it was expected that there would be no serious problems even if the permission of the lane change in tunnel and bridge sections was implemented, because the difference between in the existing solid-line sections and the pilot dotted line sections in terms of the lane change rate, the traffic characteristic, and the traffic accidents is not significant. Therefore, it needs to improve the current solid-line lane operation forbidding the lane change in tunnel and bridge sections. It is necessary to allow the lane change in tunnel and bridge sections with an appropriate level of facility conditions. In the long run, as in the cases of foreign countries, it is require to establish a principle to permit the lane change in tunnel and bridge sections. However, if necessary, it is need to consider the prohibition of the lane change in some tunnel sections by the engineering judgment. Allowing the lane change of the car in tunnel sections is not only merely a change of the lane operating method but also it is expected to be an important opportunity to increase the adherence of the driver to the laws and regulations and to change the drive culture by introducing a consistent traffic regulation.

There are various issues affecting the financial revenues of expressways, such as new transportation systems, the opening of new roads, and free toll charges. As a result, expressway toll revenues for 2017 increased only 0.3% from the previous year. If this trend continues, the steady increase in expressway revenue may have occurred, therefore it is necessary to improve the model of annual trips and revenues considering various external variables that are occurring recently. In this study, we constructed annual trips forecasting model that can analyze more precisely the changes of road network by using new independent variables (which are not considered in existing models) such as weighted length considering regional traffic volume level and private road ratio. Also we performed a basic statistical analysis on oil prices and reflected the model as a dummy variable to improve the explanatory power of the model. And we established an analysis process to estimate the toll revenue. The results of this study can be used as the basic data for expressway financial model.

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.

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.

PURPOSES: The purpose of this research is to analyze the characteristics of panels that affect the evaluating results of riding quality and to evaluate the appropriateness of roughness management criteria based on ride comfort satisfaction. METHODS: In order to analyze the influence of panel characteristics of riding quality, 33 panels, consisting of civilians and experts, were selected. Also, considering the roughness distribution of the expressway, 35 sections with MRI ranging from 1.17 m/km to 4.65 m/km were selected. Each panel boarded a passenger car and evaluated the riding quality with grades from 0 to 10, and assessed whether it was satisfied or not. After removing outlier results using a box plot technique, 964 results were analyzed. An ANOVA was conducted to evaluate the effects of panel expertise, age, driving experience, vehicle ownership, and gender on the evaluation results. In addition, by using the receiver operating characteristics (ROC) curve, the MRI value, which can most accurately evaluate the satisfaction with riding quality, was derived. Then, the compatibility of MRI was evaluated using AUC as a criterion to assess whether the riding quality was satisfactory. RESULTS: Only the age of the panel participants were found to have an effect on the riding quality satisfaction. It was found that satisfaction with riding quality and MRI are strongly correlated. The satisfaction rate of roughness management criteria on new (MRI 1.6 m/km) and maintenance (MRI 3.0 m/km) expressways were 95% and 53%, respectively. As a result of evaluating the roughness management criteria by using the ROC curve, it was found that the accuracy of satisfaction was the highest at MRI 3.1-3.2 m/km. In addition, the AUC of the MRI was about 0.8, indicating that the MRI was an appropriate index for evaluating the riding quality satisfaction. CONCLUSIONS: Based on the results, the distribution of the panels’age should be considered when panel rating is conducted. From the results of the ROC curve, MRI of 3.0 m/km, which is a criterion of roughness management on maintenance expressways, is considered as appropriate.

PURPOSES : The purpose of this study is to develop a regression model to predict the International Roughness Index(IRI) and Surface Distress(SD) for the estimation of HPCI using Expressway Pavement Management System(PMS).METHODS : To develop an HPCI prediction model, prediction models of IRI and SD were developed in advance. The independent variables considered in the models were pavement age, Annual Average Daily Traffic Volume(AADT), the amount of deicing salt used, the severity of Alkali Silica Reaction(ASR), average temperature, annual temperature difference, number of days of precipitation, number of days of snowfall, number of days below zero temperature, and so on.RESULTS : The present IRI, age, AADT, annual temperature differential, number of days of precipitation and ASR severity were chosen as independent variables for the IRI prediction model. In addition, the present IRI, present SD, amount of deicing chemical used, and annual temperature differential were chosen as independent variables for the SD prediction model.CONCLUSIONS: The models for predicting IRI and SD were developed. The predicted HPCI can be calculated from the HPCI equation using the predicted IRI and SD.

OBJECTIVES: This study aims to review a plan to reduce the shoulder width of a deformed round-trip two-lane highway with low traffic volume. METHODS: Installation of a passing lane on a round-trip two-lane (one-way one-lane) highway, and reduction of a shoulder for a round-trip four-lane highway. RESULTS : It is necessary to establish a design criterion for various highways, because the plan to reduce the lane or shoulder width of a highway with low traffic volume was analyzed to have an economic efficiency of 6.8~7.0%. CONCLUSIONS: It is necessary to seek for a plan to establish a national trunk net early by efficiently using the limited financial resources to cope with the traffic demand elastically.

PURPOSES: Concrete pavement has been used in the construction of the Jungbu expressway in 1987. More than 60% of the pavement on the expressway is currently made of concrete, but most has been used far beyond their design life. Pavement life has been extended through routine maintenance or overlay. However, the structural capacity of the pavement has reached its limit, and extensive rehabilitation/reconstruction with long time traffic blocking should be considered. The three following issues on concrete rehabilitation/reconstruction will be discussed: (1) economic comparison of asphalt inlay and asphalt overlay, (2) economic comparison preventive overlay on a section which is currently good and routine overlay on the section which will be poor, and (3) economic analysis of early-strength concrete when it is used in concrete reconstruction. METHODS: First, various life cycle cost analysis tools were compared, and the proper tool for the extensive rehabilitation/reconstruction was selected. Second, a sensitivity analysis of the selected tool was performed to find the influential input variables, which should be carefully selected in the analysis. Third, three case studies, which can be issues in the rehabilitation/reconstruction of the expressway concrete pavement in Korea, were performed. RESULTS: Asphalt overlay without milling the deteriorated concrete showed 18~25% lower life cycle cost than the current asphalt inlay with milling. The good current preventive overlay on the section was economically justified within the scope of this study. The construction cost limit of the early strength concrete was suggested to be economical for 1, 3, and 7 days of construction alternative opening. CONCLUSIONS: CA4PRS was a viable tool for comparing various rehabilitation/reconstruction issue alternatives. Several concrete issues associated with the rehabilitation/reconstruction of the deteriorated concrete pavement were discussed as mentioned above.

PURPOSES: This study was initiated to estimate expressway traffic congestion costs by using Vehicle Detection System (VDS) data. METHODS : The overall methodology for estimating expressway traffic congestion costs is based on the methodology used in a study conducted by a study team from the Korea Transport Institute (KOTI). However, this study uses VDS data, including conzone speeds and volumes, instead of the volume delay function for estimating travel times. RESULTS : The expressway traffic congestion costs estimated in this study are generally lower than those observed in KOTI's method. The expressway lines that ranked highest for traffic congestion costs are the Seoul Ring Expressway, Gyeongbu Expressway, and the Youngdong Expressway. Those lines account for 64.54% of the entire expressway traffic congestion costs. In addition, this study estimates the daily traffic congestion costs. The traffic congestion cost on Saturdays is the highest. CONCLUSIONS : This study can be thought of as a new trial to estimate expressway traffic congestion costs by using actual traffic data collected from an entire expressway system in order to overcome the limitations of associated studies. In the future, the methodology for estimating traffic congestion cost is expected to be improved by utilizing associated big-data gathered from other ITS facilities and car navigation systems.

PURPOSES : This study estimated the load effect of a single heavy truck to develop a live load model for the design and assessment of bridges located on an expressway with a limited truck entry weight. METHODS: The statistical estimation methods for the live load effect acting on a bridge by a heavy vehicle are reviewed, and applications using the actual measurement data for trucks traveling on an expressway are presented. The weight estimation of a single vehicle and its effect on a bridge are fundamental elements in the construction of a live load model. Two statistical estimation methods for the application of extrapolation in a probabilistic study and an additional estimation method that adopts the extreme value theory are reviewed. RESULTS : The proposed methods are applied to the traffic data measured on an expressway. All of the estimation methods yield similar results using the data measured when the weight limit has been relatively well observed because of the rigid enforcement of the weight regulation. On the other hand, when the estimations are made using overweight traffic data, the resulting values differ with the estimation method. CONCLUSIONS: The estimation methods based on the extreme distribution theory and the modified procedure presented in this paper can yield reasonable values for the maximum weight of a single truck, which can be applied in both the design and evaluation of a bridge on an expressway.

This study was to investigate the association among satisfaction of nutrition labeling, change of purchase behaviors, and dietary life care, based on the awareness of nutrition labeling at expressway rest areas. The subjects (n=903) were divided into two groups, according to the awareness of nutrition labeling: Awareness of Nutrition Labeling (ANL) group, n=367; Non Awareness of Nutrition Labeling (NANL) group, n=536. Effort of health care and identification of nutrition labeling was significantly higher in the ANL group, compared with the NANL group. As for the main reason for not identifying nutrition labeling, ‘not interested in nutrition labeling’ was the highest in the ANL group, and ‘Don't know nutrition labeling is provided’ in the NANL group. Identification ratio of nutrition labeling in future was significantly higher in the NANL group, compared with the ANL group among the subjects who didn't identify nutrition labeling before. After their becoming aware, a change of food purchase after reading the nutrition labeling was significantly higher in the ANL group, compared with the NANL group. Health beliefs on the nutrition labeling were significantly higher in the ANL group, compared with the NANL group. Satisfaction of nutrition labeling was also significantly higher in the ANL group, compared with the NANL group. The ANL group also expressed a necessity of expansion of nutrition labeling, compared with the NANL group. In the ANL group, identification of nutrition labeling was significantly higher in the hard effort group, compared with the little effort group of dietary life care. Therefore, improvement and campaign of nutrition labeling for consumers at expressway rest areas, especially for the NANL group, will be effective in identifying nutrition labeling for their health care.

PURPOSES : Expressways experience chronic and recurring congestion, especially during weekends and holidays, because of the increased demands for leisure-related travel. The alternatives to solve chronic and recurring congestion may be three-fold: (1) physical expansion of expressway capacities, (2) road pricing, and (3) temporal and spatial distribution of traffic demands. Among these, the third alternative may be the most cost-effective method for the Korea Expressway Corporation (KEC) that can be achieved by using the existing ITS infrastructure. METHODS : KEC initiated a pilot study in which the traffic on congested expressways was managed by providing traffic condition information (i.e., travel times) of neighboring national highways for taking detours via variable message signs (VMS). This study aimed to estimate the detour rate, and the two pilot studies on Seohaean and Yeongdong expressways yielded many benefits. RESULTS: It was revealed that the total length of congestion segments decreased by 7.8 km, and the average travel speed increased by 5.3 km/h. CONCLUSIONS: Based on these findings, it was concluded that the propagation of detour information via VMSs during congestion hours can help reduce congestion on expressways and increase the benefits of the entire network.

PURPOSES : The Toll Collection System (TCS) operated by the Korea Expressway Corporation provides accurate traffic counts between tollgates within the expressway network under the closed-type toll collection system. However, although origin-destination (OD) matrices for a travel demand model can be constructed using these traffic counts, these matrices cannot be directly applied because it is technically difficult to determine appropriate passenger car equivalent (PCE) values for the vehicle types used in TCS. Therefore, this study was initiated to systematically determine the appropriate PCE values of TCS vehicle types for the travel demand model. METHODS: To search for the appropriate PCE values of TCS vehicle types, a traffic demand model based on TCS-based OD matrices and the expressway network was developed. Using the traffic demand model and a genetic algorithm, the appropriate PCE values were optimized through an approach that minimizes errors between actual link counts and estimated link volumes. RESULTS : As a result of the optimization, the optimal PCE values of TCS vehicle types 1 and 5 were determined to be 1 and 3.7, respectively. Those of TCS vehicle types 2 through 4 are found in the manual for the preliminary feasibility study. CONCLUSIONS: Based on the given vehicle delay functions and network properties (i.e., speeds and capacities), the travel demand model with the optimized PCE values produced a MAPE value of 37.7%, RMSE value of 17124.14, and correlation coefficient of 0.9506. Conclusively, the optimized PCE values were revealed to produce estimates of expressway link volumes sufficiently close to actual link counts.

PURPOSES: The purpose of this study is to analyze the service life of expressway pavement based on both traffic volumes and use of deicing chemicals. METHODS: A database was built using expressway rehabilitation history information from over the last decade. In order to estimate the service life of expressway pavement, various analysis methods were considered, and a decision was made to perform analysis using a method based on an accumulated rehabilitation ratio. The service life of expressway pavement was then analyzed by classifying the scale of traffic volume and extent of de-icing chemicals used. RESULTS: The service life of PMA and SMA ranged from 7.8 to 10.6 years and from 9.9 to 12.0 years, respectively. The service life of JCP ranged from 16.0 to 22.2 years, and the service life of CRCP was 33.5 years on average. Results of assessing service life according to traffic volumes and de-icing chemicals showed that the lower the traffic volumes were, the greater the service life of PMA and JCP, and the less that de-icing chemicals were applied, the greater the service life of JCP. CONCLUSIONS : The dependence of expressway pavement service life on traffic volumes and de-icing chemicals makes it possible to apply LCCA for regional maintenance plans and cost-effective selection of expressway pavement type.

PURPOSES : The bridge section of the expressway has a worse driving environment than the general section. However, traffic safety countermeasures are focused only on the bridge section. Traffic safety countermeasures on the section before entry to the bridge and the section after exit from the bridge are applied only when the bridge has a long-span section. Accordingly, this study will verify the necessity of extending the application of traffic safety countermeasures to areas that are affected by the bridge. METHODS: This study determines the areas that are affected by the bridge as well as the areas that are affected by locations with frequent traffic accidents and suggests the risk factors by affected areas through canonical discriminant analysis. For the analysis, traffic accident data for 3 years, which occurred on bridge sections in six major expressway lines, were used. RESULTS: The numbers of traffic accidents were 469 before the bridge, 281 on the bridge, and 468 after the bridge. The variables that have impact on the seriousness of accidents are as follows: speeding, excess manipulation of the steering wheel, and failure to secure safety distance for accidents that occurred before the bridge section; speeding, excess manipulation of the steering wheel, and dozing off for accidents that occurred on the bridge; and speeding and failure to secure safety distance for accidents that occurred after the bridge section. CONCLUSIONS : Areas affected by the bridge show higher accident rates than the bridge section; therefore, imposing traffic safety countermeasures on the integrated section of the bridge and the affected areas is required. It is believed that the results suggested in this study could be effectively used in the prevention of traffic accidents by imposing custom-made safety countermeasures for each section.

PURPOSES: Used in transportation planning and traffic engineering, almost traffic simulation tools have input variable values optimized by overseas traffic flow attribution because they are almost developed in overseas country. Thus, model calibration appropriated for internal traffic flow attribution is needed to improve reliability of simulation method. METHODS : In this study, the traffic flow model calibration is based on expressways. For model calibration, it needs to define each expressway link according to attribution, thus it is classified by design speed, geometric conditions and number of lanes. And modified greenshield model is used as traffic flow model. RESULTS : The result of the traffic model calibration indicates that internal congested density is lower than overseas. And the result of analysis according to the link attribution indicates that the more design speed and number of lanes increase, the lower the minimum speed, the higher the congested density. CONCLUSIONS: In the traffic simulation tool developed in overseas, the traffic flow is different as design speed and number of lanes, but road segment don't affect traffic flow. Therefore, these results need to apply reasonably to internal traffic simulation method.

PURPOSES: This study analyzes the available working time at work-zone on the Expressway in accordance to the new capacity manual. METHODS: Sensitivity analysis on variables were conducted to calculate the adjusted capacity at work-zone based on previous researches. RESULTS : The main factors which affect available working time at the work-zone were its capacity, number of lanes, terrain and lane width. Other factors have minimal effect on the available working time. Based on the analysis, a calendar of lane closures was suggested. CONCLUSIONS : A series of studies concluded that the capacity at work-zone in the new capacity manual reduced to 76-82% of the existing manual. As such, the available working time decreased. Furthermore, the factors affecting the available working time needs to be considered when making a plan to rehabilitate the distressed pavement.

PURPOSES: By conducting the landscape survey that considered landscape factors of the Guide Coating in the Median Barrier that applied of the various level by simulating of the Guide Coating in the Median Barrier on the expressway, they showed the quantitative standard of landscape preference factors that the Guide Coating gives. METHODS: The shape of the Structural Equation Modeling used AMOS program and made a shape that is made of landscape preference for the Guide Coating in the Median Barrier on the expressway a dependent variable. RESULTS: Result in this, they showed that functionality and emotionalism are the factors that affect the landscape preference. CONCLUSIONS: In the main study, not only showing the Guide Coating in the Median Barrier on the expressway landscape valuation but also embodying the Structural Equation Modeling(SEM) of each group, knowing the Guide Coating and unknowing the Guide Coating. By embodying this, they could study that the drivers' quantitative standard is different when the Guide Coating become first applied and being changed after.