• Journal of the Korean Society of Marine Environment & Safety
• /
• v.24 no.4
• /
• pp.381-388
• /
• 2018

This study proposes marine traffic volume estimation method considering ship speed, a factor excluded from the existing method. Ten days of GICOMS marine traffic data from Pyeongtaek and Dangjin ports was applied to this study. As a result, converted traffic volume with the proposed estimation method showed an increase of 4.41 (${\pm}0.99$) times or decrease of 0.59 (${\pm}0.04$) at most, compared with the existing estimation method. Average marine traffic congestion for each time applying the proposed estimation method showed an increase of 1.43 (${\pm}0.10$) compared with the existing estimation method. The maximum marine traffic congestion for each time was 1.62 (${\pm}0.34$) times higher compared with the existing estimation method. Marine traffic peak time, defined as the highest point of marine traffic congestion, was evaluated to be different from that of the existing method because of distribution of vessel speed. In conclusion, considering ship speed is necessary when estimating marine traffic volume to produce a practical estimate of marine traffic capacity.

• Journal of the Korean Society of Safety
• /
• v.31 no.3
• /
• pp.143-155
• /
• 2016

Recently, a massive loss of life and property is occurring in Korea due to traffic accidents, with the rapid increase in cars. For improvement of traffic safety, the Korea Transportation Safety Authority intensively analyzes accident data in local governments with low traffic safety index, performs a field investigation to extract problems and offers local governments improvements for problems, by conducting the 'Special Survey of Actual Conditions of Traffic Safety' each year, starting 2008. But local governments cannot strongly push forward the improvement projects due to the limited budget and the uncertainty of the improvement plan effects. Therefore, this study suggested a model which applied the Utility concept to the AHP theory, in order to efficiently decide a priority of the improvement plans in accident black spots in consideration of the limited budget of local governments. The number of accidents in each spot for improvement and accident severity, traffic volume, pedestrian volume, the improvement project cost and the accident reduction effect were chosen as evaluation factors for deciding a priority, and data about the improvement plan costs and the accident reduction effects, traffic accidents and traffic volume in the spots to undergo the special research on the real condition of traffic accident in the past were collected from the existing studies. Then, regression analysis was carried out and the Utility Curve of each evaluation factor was computed. Based on the AHP analysis findings, this study devised a priority decision method which calculated the weight and the utility function of each evaluation factor and compared the total utility values. The AHP analysis findings showed that among the evaluation factors, accident severity had the biggest importance and it was followed by the improvement plan cost, the number of accidents, the improvement effect, traffic volume and pedestrian volume. The calculated utility function shows a rise in utility, as the variables of the 5 evaluation factors; the number of accidents, accident severity, the improvement plan effect, traffic volume and pedestrian volume increase and a fall in utility, as the variables of the improvement plan cost increase, since the improvement plan cost is included in the budget spent by a local government.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.6
• /
• pp.2427-2435
• /
• 2013

Design hourly volume and the K-factor, first proposed by FHWA in the 1950s, is based on the 30th hourly traffic volume during a year (out of 8,760 hours). It was used when surveying the traffic volume was laborious in the past and is still being used now although it leaves some to be desired for practical applications. More reasonable K-factor for better design, based on theoretical evidence, is needed. This paper proposes the knee searching method based on simple linear regression to find out the inflection point of the volume ranking curve that describe the annual 8,760 hourly traffic volumes. The method was applied to the Chungcheong province's national highway, and the results were compared to the existing guidelines' values of K-factors. Identified design hourly traffic volumes ranked between 43rd to 694th, which is much lower than the 30th volume, meaning that some overdesign examples are inevitable if the conventional $30^{th}$ volume is used.

• Journal of the Economic Geographical Society of Korea
• /
• v.21 no.2
• /
• pp.107-118
• /
• 2018

Due to the rapid economic development, traffic congestion has become a dire concern in Beijing, China. Levying a congestion toll is seen as the most effective solution to the problem. Building a congestion pricing model is a crucial step in implementing a workable toll scheme. Unlike previous attempts, this study not only covers the theoretical discussion but also considers three practical issues: the speed-density relationship, the value of travel time savings, and the determination of optimal traffic volume. We estimate the speed-density relationship by regression models and the value of travel time saved through survey results. We further suggest a way through which the government could identify the optimal traffic flow by a series of trial-and-errors, without the knowledge of exact road demand structure. Finally, a practical tolling scheme is proposed for Beijing's second ring road along with some policy recommendations.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.19 no.3
• /
• pp.116-128
• /
• 2020

This study compared the delays of scramble crosswalks and general crosswalks, considering the pedestrian and vehicle traffic at intersections. Based on the signal theory, this study used traffic delays as a measure of feasibility of installing scramble crosswalks. The road structure and length of signal lights were assumed to be specific numbers to calculate the delays in vehicles and pedestrians. With the computed delays, this study compared general crosswalks and scramble crosswalks, and evaluated the feasibility sections on the installation of scramble crosswalks using circular and non-circular signal phases, respectively. The analysis confirmed that the introduction of scramble crosswalks might be more appropriate when the traffic ratio on the main roads is high. In addition, the application of non-circular signal phases is more proper for the operation of scramble crosswalks than circular signal phases. In the non-circular signaling system, however, it was shown that diagonal crosswalks might not be practical if the demand for diagonal crossing is too low. These results are expected to contribute to the development of basic guidelines for assessing the installment feasibility of scramble crosswalks in terms of traffic operation and efficiency.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.15 no.2
• /
• pp.63-73
• /
• 2016

On January 16 to May 31, 2012, Korea Expressway Corporation was carried out an pilot overweight enforcement using high-speed weigh-in-motion at Gyeongbu expressway 195.0k (Gimcheon) and Jungbunaeryuk expressway 119.5k (Seonsan). In this study, it is attempted to analyze the practical effect of high-speed weigh-in-motion by comparing the average total weight and traffic volume of eight weeks before and after the these overweight enforcement, respectively. The main results are as follows: First, the result of analysis of the change in average total weight and traffic volume, it was found that it did not differ after as in previous traffic volume, and the total weight is reduced. This means that the total weight is not reduced by decreasing freight traffic, but by decreasing the total weight. Therefore, it can be seen that there is an effect of pilot overweight enforcement using high-speed weigh-in-motion. Second, the average total weight and total weekly traffic volume decreased rapidly starting from the start of the overweight enforcement, but there was showing a tendency to increase gradually again.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.18 no.5
• /
• pp.416-422
• /
• 2012

To prevent serious maritime accident and eliminate the cause of the potential maritime accidents, Maritime Safety Audit Scheme was formally institutionalized through amendment of Maritime Traffic Safety Act(May 27, '09). At the initial step of the enforcement of the law, it has risen the necessity of amending the present institution concerning with the range of applicable business, method of practice, detailed technical standards in the assessment articles, etc. Among them, the assessment of marine traffic congestion has been practiced as a mandatory assessment article, but it is analyzed that the assessment doesn't reflect current variation of ships' size and its speed. By analyzing the status of assessments on marine traffic congestion so far and collecting experts' opinion, this paper suggests draft amendments to improve technical standards on the assessment of marine traffic congestion.

• Journal of Korean Society of Transportation
• /
• v.25 no.4
• /
• pp.21-32
• /
• 2007

The households to be surveyed are usually huge number at the level of a city or metropolitan survey, not to mention a nationwide travel survey. Therefore, household travel surveys to figure out true origin-destination (O/D) trip patterns (population O/D) are conducted through a sampling method rather than by surveying all of the population in the system. Therefore, the population O/D pattern can only be estimated by expanding the sampled O/D patterns to the population. It is very difficult to avoid the errors involved in the process of sampling, surveying and expanding O/D data. In order to minimize such errors while estimating the true O/D patterns of the population, the validation and adjustment process should employed by doing a comparison between the expanded sample O/D data and observed link traffic volumes. This study suggests a method of validation and adjustment of the expanded sample O/D data by comparing observed link volumes at several screenlines. The study also suggests a practical technique to modify O/D pairs which are excluded in the screenline validation process by comparing observed traffic volume with the results of traffic assignment analysis. An empirical study was also conducted as an example applying the suggested methods of validation and adjustment with Korea's nationwide O/D data and highway network.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.13 no.4
• /
• pp.20-29
• /
• 2014

Density is applied both three major macroscopic traffic variables (traffic volume, speed, and density) and two measures of effectiveness (MOE) for level of service (LOS) on highway (density and V/C). Especially, it is known for the most accurate MOE on evaluating the LOS of highway. Despite such importance, there is a lack of study on density relatively than other variables for its difficulty of measurement. Existing density estimation methods have some limitations such as density values of same traffic flow vary with collecting time. In this study, we researched actual density measuring method with panoramic image, after each CCTV images in the Sapaesan Tunnel on Seoul Ring Expressway are matched into one panoramic image. Analysis through the Central Limit Theorem shows that density of 24 1 km-images, which means 24 second, applies traffic situation well. That is to say that reasonable density value regardless of collecting time, and practical density which represents actual traffic flow can be taken in case of measuring density by suggested collecting cycle.

• Journal of Korean Society of Transportation
• /
• v.26 no.5
• /
• pp.17-28
• /
• 2008

This study examines the ramp-up analysis techniques which have been introduced till now and presents the strength and weakness of each method. The applicability of each technique was reviewed using a case study involving the data of Cheonan-Nonsan motorway usages where seasonal variations of the data were removed. The results showed that all the techniques except F-test have the same ramp-up period of 12 months. The level of Tamp-up was 65%-72% compared to that of the real traffic volume at the beginning of opening. The demand recovered to the stabilized level as time goes on. To apply the methodology to practical demand forecasts actual surveys of real data of traffic demand should be performed. With these efforts to the patronage ramp-up, more reliable demand analyses can be accompanied.