• International Journal of Highway Engineering
• /
• v.14 no.6
• /
• pp.75-84
• /
• 2012

PURPOSES : This paper aims to improve the evaluation method of the Level of Service(LOS) for urban streets presented by the current Korean Highway Capacity Manual(KHCM) and suggest its utilization plan as a part of the methods to evaluate the sustainability of a transportation policy. METHODS : This paper carried out a research in 3 steps to develop a new evaluation method. First of all, this paper reviewed the previous studies related to the LOS of urban streets and the socially requested items for a sustainable transportation system. Then this paper derived an index and weight through expert questions to select an evaluation index. Lastly, this paper compared the results according to the existing evaluation methods with the new evaluation methods through case studies. This paper used an Analytic Hierarchy Process(AHP) for importance analysis and weight selection between new evaluation items and indices, and applied a Grey System Theory(GST) for a synthetic and integrated evaluation between the selected evaluation indices. RESULTS : As a result of evaluating the LOS according to the existing evaluation methods and the integrated evaluation methods using a GST through case studies, it was analyzed that new methods' results are less than or equal to the existing evaluation methods; and as a result of applying a weight between evaluation indices according to AHP, it was noticed that the total score seems to rise more when the LOS in the existing evaluation is calculated lower. It was analyzed that the LOS calculated by reflecting the newly established evaluation items and the importance between indices in this study has difference from the LOS of the existing urban streets. CONCLUSIONS : It is expected that this evaluation method can diagnose the current conditions when establishing a future sustainable traffic system and can be used for the measurement of the sustainability effects of the improvement plans and so on.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.20 no.6
• /
• pp.1-13
• /
• 2021

In this study, a time series analysis technique was applied to calibrate and predict traffic data for various purposes, such as planning, design, maintenance, and research. Existing algorithms have limitations in application to data such as traffic data because they show strong periodicity and seasonality or irregular data. To overcome and supplement these limitations, we applied the SARIMA model, an analytical technique that combines the autocorrelation model, the Seasonal Auto Regressive(SAR), and the seasonal Moving Average(SMA). According to the analysis, traffic volume prediction using the SARIMA(4,1,3)(4,0,3) 12 model, which is the optimal parameter combination, showed excellent performance of 85% on average. In addition to traffic data, this study is considered to be of great value in that it can contribute significantly to traffic correction and forecast improvement in the event of missing traffic data, and is also applicable to a variety of time series data recently collected.

• Proceedings of the KOR-KST Conference
• /
• 1995.12a
• /
• pp.45-73
• /
• 1995

The current paper presents a system dynamics model which can generate the land use anq transportation system performance simultaneously is proposed. The model system consists of 7 submodels (population, migration of population, household, job growth-employment-land availability, housing development, travel demand, and traffic congestion level), and each of them is designed based on the causality functions and feedback loop structure between a large number of physical, socio-economic, and policy variables. The important advantages of the system dynamics model are as follows. First, the model can address the complex interactions between land use and transportation system performance dynamically. Therefore, it can be an effective tool for evaluating the time-by-time effect of a policy over time horizons. Secondly, the system dynamics model is not relied on the assumption of equilibrium state of urban systems as in conventional models since it determines the state of model components directly through dynamic system simulation. Thirdly, the system dynamics model is very flexible in reflecting new features, such as a policy, a new phenomenon which has not existed in the past, a special event, or a useful concept from other methodology, since it consists of a lots of separated equations. In Chapter I, II, and III, overall approach and structure of the model system are discussed with causal-loop diagrams and major equations. In Chapter V _, the performance of the developed model is applied to the analysis of the impact of highway capacity expansion on land use for the area of Montgomery County, MD. The year-by-year impacts of highway capacity expansion on congestion level and land use are analyzed with some possible scenarios for the highway capacity expansion. This is a first comprehensive attempt to use dynamic system simulation modeling in simultaneous treatment of land use and transportation system interactions. The model structure is not very elaborate mainly due to the problem of the availability of behavioral data, but the model performance results indicate that the proposed approach can be a promising one in dealing comprehensively with complicated urban land use/transportation system.

• International Journal of Highway Engineering
• /
• v.12 no.1
• /
• pp.79-86
• /
• 2010

Cold in-place recycling (CIR) using emulsified asphalt or foamed asphalt has become a more common practice in rehabilitating the existing asphalt pavement due to its cost effectiveness and the conservation of paving materials. As CIR continues to evolve, the engineered emulsified asphalt was developed to improve the field performances such as coating, raveling, retained stability value and curing time. The main objective of this research is to compare the laboratory responses of the engineered emulsified asphalt (CIR-EE) mixtures against the foamed asphalt (CIR-foam) mixtures using the reclaimed asphalt pavement (RAP)materials collected from the CIR project on U.S. 20 Highway in Iowa. Based on the visual observation of laboratory specimens, the engineered emulsified asphalt coated the RAP materials better than the foamed asphalt because the foamed asphalt is to create a mastic mixture structure rather than coating RAP materials. Given the same compaction effort, CIR-EE specimens exhibited lesser density than CIR-foam specimens. Both Marshall stability and indirect tensile strength of CIR-EE specimens were about same as those of CIR-foam specimens. However, Marshall stability and indirect tensile strength of the vacuum-saturated wet specimens of CIR-EE mixtures were higher than those of CIR-foam mixtures. After four hours of curing in the room temperature, the CIR-EE specimens showed less raveling than the CIR-foam specimens. On the basis of test results, it can be concluded that the CIR-EE mixtures is less susceptible to moisture and more raveling resistant than CIR-foam mixtures.

• Journal of Korean Society of Transportation
• /
• v.33 no.4
• /
• pp.348-356
• /
• 2015

In 2026, in ten years from now, Korea is expected to enter into a super aged society. By facing this social phenomenon, analyzing the elderlies and preparing measures are needed among society. In the transportation field, the traffic accidents which are related to the elderly pedestrians have drastically increased so that R&D projects and policy supplementations are introduced. However very few base studies on which focused on the behavior, capability, impact factors analysis of for elderly pedestrians are conducted. To determine the walking capability, this study divided the walking capability into 3 three categories - general, health and exercise. It carries out the comprehensive survey targeting 52 elderlies with the average age of 72.6 years and this survey is made up of total 12 factors in the 3 three categories. This survey also is conducted with various measuring devices and methods such as interview, National Fitness Award, SPBB, Cybex and the like for. From the 12 detailed factors, the general factors such as age, physical shape and so forth have little impact on the walking speed. However the factors that have the greatest impact on the walking speed are extensor muscle on lower limbs in the health factors and balance, coordination, and SPPB in the exercise factors. With these results, this study develops the independent walking model which can measure the walking capability of the elderly people. The developed model is expected to be utilized as the base study for elderly's walking patterns in the transportation field by examining the walking capability of the older people.

• Journal of Cadastre & Land InformatiX
• /
• v.51 no.2
• /
• pp.83-106
• /
• 2021

Interests in clean fuels have been soaring because of environmental problems such as air pollution and global warming. Unlike fossil fuels, hydrogen obtains public attention as a eco-friendly energy source because it releases only water when burned. Various policy efforts have been made to establish a hydrogen based transportation network. The station that supplies hydrogen to hydrogen-powered trucks is essential for building the hydrogen based logistics system. Thus, determining the optimal location of refueling stations is an important topic in the network. Although previous studies have mostly applied optimization based methodologies, this paper adopts machine learning to review spatial attributes of candidate locations in selecting the optimal position of the refueling stations. Machine learning shows outstanding performance in various fields. However, it has not yet applied to an optimal location selection problem of hydrogen refueling stations. Therefore, several machine learning models are applied and compared in performance by setting variables relevant to the location of highway rest areas and random points on a highway. The results show that Random Forest model is superior in terms of F1-score. We believe that this work can be a starting point to utilize machine learning based methods as the preliminary review for the optimal sites of the stations before the optimization applies.

• Journal of Korean Society of Transportation
• /
• v.25 no.5
• /
• pp.101-109
• /
• 2007

Two variations of toll roads exist: mainline toll plazas and entry/exit tolls. On a mainline toll system(open toll scheme), all vehicles stop at various locations along the highway to pay a toll. While this may save money from the lack of need to construct tolls at every exit, it can cause lots of traffic congestion, and drivers could evade tolls by going around them. With entry/exit tolls, vehicles collect a ticket when entering the highway, which displays the fares it will pay when it exits, increasing in cost for distance travelled. Upon exit, the driver will pay the amount listed for the given exit. The pressures on the Seoul ring roadway network have been changing over time. In the past, the emphasis was on mobility and maintenance of the road network to provide an efficient transportation network, but recently, road use has outstripped the network's ability to extend and expand the road network and hence the policy emphasis has moved towards reducing free riders rather than mitigating its effects. In addition to this pressure is an incidental pressure, which argues that provision of free ride segments generates further traffic in isolation of other factors. This paper is examining policies to reduce the burden of traffic congestion in Seoul ring roadway which is used open toll scheme for decades. One key mechanism to achieve this policy aim is automatic charging mechanism on freeway, but if a nation-wide electronic toll collection is to be implemented successfully, there are a number of prerequisites which must be place.

• International Journal of Highway Engineering
• /
• v.12 no.1
• /
• pp.71-78
• /
• 2010

Rapid urbanization causes a variety of transportation problems, including traffic delay. Then transportation engineers would get involved in trying to solve traffic delay through road constructed and uncongested policy. But lately, traffic policy changed from vehicle-dominated to humandominated and green transportation. Road diet is one of green transportation. Road diets reduce the number of lanes, lane width because supplement space for green transportation including a bicycle road, side-walk, etc. A study on road diets not enough then this study performed a basic study for road diets. This study on lane width reduce for road diets through analyzes sway of moving vehicle. This study results shows lane width of a compacts-size car needs 2.34~2.70m and lane width of a full-size car needs 2.62~2.89m. According to this study lane width can reduce therefore lane width design criterion have to be relieved. This study will be used in a road width reduce including a road diets, road in process of construction and so on.

• International Journal of Highway Engineering
• /
• v.8 no.4 s.30
• /
• pp.145-157
• /
• 2006

Generally, the method of the policy analysis has been used for making a policy decision of the development project of the road through the expert interview based on AHP. According to introducing PI, the study of the method of the integrating process for various opinion of the related groups is required. On this study I evaluate what is a difference between the results of integrated process and the AHP analysis on what is major considering factor in decision-making process. From the analysis, each evaluate factor is in level of significance by ANOVA. First, there is a significance level difference between Group A, C and Group B Second, there is also a significance level difference on the result of AHP analysis for each group in order to evaluate by integrated method. Finally, the method of AHP analysis which considers priority factor is expected as to be useful tool on decision-making of various group.

• Journal of Digital Convergence
• /
• v.9 no.5
• /
• pp.55-63
• /
• 2011

The purpose of this study is analyzes the violate behavior the Parking Area for the handicapped and monitor the management problem, therefore presents the improvement alternatives of it. We use the field interview survey method by visiting the government office of cities of 16, commercial facility, housings, medical centers, cultural and sports facilities, express highway rest area. We visited the 50 places and interviewed the 227 violating persons. As a result, violate behavior is divided into the not attachment of sticker on parking possibility and not accompaniment with walking disabled person. We presented the improvement alternatives for the lawful usage of the parking area for the handicapped. First, We have to magnify a recognition and a advertisement about the parking area for the handicapped. Second, We have to improve a management of expense, manpower and civil complains, etc. We have to prepare the legal revision which strengthens the concrete punishment for a violate behavior improvement.