• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.5
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• pp.124-134
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• 2011

To make popular the NEV(Neighborhood Electric Vehicles) uses, it must be considered the supply of infrastructure and the political decision for NEV. However, the guidelines of infrastructure for NEV are not prepared. The guidelines of infrastructure for NEV should be performed in many research and case. The purpose of this study is to reveal the influence of NEV on the two-lane highway traffic flows by TWOPAS simulation model. The main items to check the influence are Average Travel speed, Percent Time Spent Following and Total Delay. The scenario were setup by traffic volume. And the NEV percentages are changed from 1% ~ 30%. The scenario 1 which traffic volume are 650veh/h and the scenario 4 which traffic volume are 2,600veh/h are less influenced by NEV, compare to scenario 2, scenario 3. Because the scenario 1 is more free to make passing other cars and Scenario 4 is fully saturated with existing traffic volumes. The urban two-lane highway which has much traffic volume and the rural two-lane highway which has little traffic volume has affinity for NEV than the other two-lane highway.

• Journal of Navigation and Port Research
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• v.46 no.4
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• pp.321-330
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• 2022

Busan New Port manages the largest volume of traffic among Korean ports, and accounts for 68.5% of the total volume of the Busan port. Due to this increase in volume, ultra large container ships call at Busan New Port. When the additional south container terminal as well as ongoing construction project of the west container terminal are completed, various encounters may occur at the Busan New Port entrance, which may cause collision risk.s Thus, the purpose of this study was to provide a plan to improve the safety of vessel traffic, in the in/out bound fairway of Busan New Port. For this purpose, the status of arrivals and departures of vessels in Busan New Port, was examined through maritime traffic flow analysis. Additionally, risk factors and safety measures were identified, by AHP analysis with ship operators of the study area. Also, based on the derived safety measures, scenarios were set using the Environmental Stress model (ES model), and the traffic risk level of each safety measure was identified through simulation. As a result, it is expected that setting the no entry area for one-way traffic would have a significant effect on mitigating risks at the Busan New Port entrance. This study can serve as a basis for preparing safety measures, to improve the navigation of vessels using Busan New Port. If safety measures are prepared in the future, it is necessary to verify the safety by using the traffic volume and flow changes according to the newly-opened berths.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.7
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• pp.858-862
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• 2018

The purpose of this study is to improve the current vessel departure control regulations to prevent traffic congestion after the lifting of vessel departure controls due to restricted visibility. AIS data was collected to analyze the traffic volume of normal traffic flow and after departure control. A statistical test was conducted to confirm the difference in traffic volume at peak hours according to whether or not departure control was used. The results of the t-test showed that there was a significant difference in traffic volume among groups of less than 10,000 tons in gross tonnage. However, the Mann-Whitney test showed no difference in traffic volume regardless of vessel control. Small and medium-sized vessels of less than 10,000 tons after departure control increased in traffic volume by 142% over normal traffic, and it was concluded that traffic congestion resulted as these small and medium-sized vessels were departing at the same time as large vessels of more than 10,000 tons. In order to prevent vessel collision accidents due to traffic congestion, it is suggested that the navigability of vessels less than 160 m or less than 10,000 tons should be improved.

• Journal of the Korean Society of Safety
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• v.32 no.3
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• pp.123-129
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• 2017

This study deals with the traffic accident of truck at circular intersection. The purpose of this study is to develop the truck accident models based on type of accident and conflict. In pursuing the above, the study gives particular attentions to selecting the appropriate models among Poisson and Negative binomial models using statistical program LIMDEP 8.0. The traffic accident data from 2007 to 2014 are collected from TAAS data set of Road Traffic Authority. Such the dependent variable as number of truck accidents and the 24 independent variables as geometry, traffic volume and others are used. The main results are as follows. First, 5 Poisson models (${\rho}^2$ of 0.164~0.351) which are all statistically significant are selected. Second, the common variable based on type of accident and conflict is analyzed to be truck apron width. The specific variables are, however, evaluated to splitter island, area of splitter island, speed limit sign, truck apron, number approach road, circular intersection sign, speed hump and traffic volume. Finally, widening the truck apron width and improving the above specific variables are analyzed to be important for truck accident reduction at circular intersections.

• KDI Journal of Economic Policy
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• v.35 no.4
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• pp.31-61
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• 2013

The purpose of this study is to calculate the economic value of transport demand forecasting risks in the road PPP project. Under the assumption that volatility of the road PPP project value occurs only in regard with uncertainty of traffic volume forecasting, this study calculates the economic value of the traffic forecasting risks in the case of the road PPP project. To that end, forecasted traffic volume is assumed to be a stochastic variable and to follow the Geometric Brownian motion as time passes. In particular, this study attempts to differentiate itself from existing studies that simply use an arbitrary assumption by presenting the application of different traffic volume growth volatility and the rates before and after the ramp-up period. Analysis of the case projects reveals that the risk premium related to traffic volume forecast of the project turns out as 7.39~8.30%, without considering option value-such as minimum revenue guarantee-while the project value volatility caused by transport demand forecasting risks is 17.11%. As the discount rate grows higher, the project value volatility tends to decrease and volatility in project value is always suggested to be larger than that in transport volume influenced by leverage effect due to fixed expenditure. The market value of transport demand forecasting risk-calculated using the project value volatility and risk premium-is analyzed to be between 0.42~0.50, implying that a 1% increase or decrease in the transport amount volatility would lead to a 0.42~0.50% increase or decrease in risk premium of the project.

• Journal of the Korean Society of Safety
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• v.32 no.4
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• pp.107-113
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• 2017

This paper deals with the traffic factors related to the collisions of circular intersections. The purpose of this study is to develop traffic accident models by type of collision based on land use. In pursuing the above, the traffic accident data from 2010 to 2014 were collected from the "Traffic Accident Analysis System (TAAS)" data set of the Road Traffic Authority. A multiple regression model was utilized in this study to develop the traffic accident models by type of collision. 17 explanatory variables such as geometry and traffic volume factors were used. The main results are as follows. First, the null hypothesis that the type of land use does not affect the number of accidents by type of collision is rejected. Second, 10 accident models by type of collision based on land use are developed, which are all statistically significant. Finally, the ADT, inscribed circle diameter, bicycle lane, area of central island, number of speed hump, circulatory roadway width, splitter island, area of circulatory roadway, mean number of entry lane and mean width of entry lane are analyzed to see how they affect accident by type of accident based on land use.

• International Journal of Highway Engineering
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• v.12 no.4
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• pp.61-70
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• 2010

The purpose of this study is to analyze the accuracy of traffic volume forecast by comparing an estimated to real traffic volume. For this study, total 10 sections of national highways, which are planned in 1980s and 1990s, were selected and traffic analysis data for highway construction were collected. In addition, targeted 10 sections were categorized into network-related and -unrelated sections. In the analysis of inaccuracy between the estimated and real traffic, for network-related sections, appeared to have lower inaccuracy. As time goes on after traffic open, inaccuracy between the estimated and real traffic appeared to be lower. In various section lengths, the longer the section length, the higher the inaccuracy is. Using 3 years passed data after traffic open, national highway have lower inaccuracy than expressway. However, the traffic analysis according to traffic open time resulted in little change of the inaccuracy.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.3
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• pp.298-305
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• 2019

The demand for the revitalization of marine tourism in Busan North Port is increasing due to changes in functions such as an increase in harbor traffic volume and the expansion of marine leisure space in Busan. As a result, Busan City plans to set a phased alleviation target for prohibition of cruise ship operations, and to lift the prohibition of excursion ship operations in North Port following the cancellation of the prohibition of excursion ship operations in South Port in 2017. The purpose of this study is to evaluate the risk of excursion ship operations in Busan North Port by applying the marine traffic assessment index and to examine the possibility of excursion ship operations. For this purpose, port status, marine accidents, and traffic flow of Busan North Port were investigated. In addition, marine traffic assessment indexes, such as traffic congestion, risk based on an ES Model, and IWRAP MkII, a maritime risk assessment tool, were used to assess the risk and possibility of excursion ship operations in Busan North Port. This study can be used as basic data for analyzing the risk factors that may occur when excursion ships are operated in Busan North Port and to define how excursion ships should operate, with related safety measures.

• Journal of Korean Society of Transportation
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• v.26 no.3
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• pp.17-29
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• 2008

A volume-delay function(VDF) has been used to describe the relation between traffic volumes and delay experienced by travelers on the roads traveling from origin to destination, which has been usually adopted in traffic assignment. For the purpose of more precise description of traffic pattern, we have to estimate the parameters of VDF in advance. This paper presents a methodology for estimating the parameters, which combined with golden section method. By using the method we have estimated the parameters with real data based on KTDB(2006), and validated them. Compared to the existing values of the parameters, newly estimated values are found to be closer to real world.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.925-932
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• 2018

This study deals with Turbo-Roundabout of Special-Roundabouts. Recently, many rotary intersections are being constructed in Korea, but the effect of the rotary intersection depends on the total entrance traffic volume and the area of the paper. The purpose of this study is to analyze the operation and accident reduction effect of turning traffic signal intersection with small traffic volume into turbo - type turning intersection. The main results are as follows. First, when the traffic volume of the main road is high, the traffic volume of the subway is less than 10 ~ 15%, or when the left turn ratio is less than 30%, it is improved when switching to the turbo type turn intersection instead of the first turn type and second turn type turn intersection Was analyzed. Second, it is considered that turbo type rotary intersection is more effective than first - type rotary intersection, and it is more effective in increasing road capacity because the area of paper is smaller than that of second - order rotary intersection. Third, the number of traffic accidents decreased by 45.9% and the number of injured persons decreased by 76.5% after the conversion of the turnover type turnover to turbo type. 100%), the number of car accidents was 0.3, and the number of casualties was 0 (100%). Finally, the positive evaluation of the user satisfaction survey showed that the improvement in safety, accessibility, and convenience was improved by 60.4%, which was improved by 16.4% to 76.8% after the conversion to the turbo type turnover.