• Journal of Korean Society of Transportation
• /
• v.34 no.2
• /
• pp.123-134
• /
• 2016

Traffic accident at intersections takes 44.3% of total number of accidents on entire road network of Korea in 2014. Although several studies addressed contributory factors of accidents at signalized intersection, very few is known about the factors at rural unsignalized intersections. The objective of this study is therefore to investigate specific characteristics of crashes at rural unsignalized intersection and to identify contributory factors in causing crashes by statistical approach using the Ordered Logistic Regression Model. The results show that main type of car crashes at unsignalized intersection during the daytime is T-bone crashes and the number of crashes at 4-legged intersections are 1.53 times more than that at 3-legged intersections. Most collisions are caused by negligence of drivers and violation of Right of Way. Based upon the analysis, accident severity is modeled as classified by two types such as 3-legged intersection and 4-legged intersection. It shows that contributory factors in causing crashes at rural unsignalized intersections are poor sight distance problem, average daily traffic, time of day(night, or day), angle of intersection, ratio of heavy vehicles, number of traffic violations at intersection, and number of lanes on minor street.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.10 no.3
• /
• pp.25-35
• /
• 2011

Traffic volume increases due to diversification of industry. Also, Automobile ownerships also increase steadily. It is estimated that the registered number of vehicle is expected to be 20 milion in the year 2015. These trends may result in increasing the number of woman drivers and elderly drivers. Therefore, this study aims to identify routes that reflect characteristics of each driver's preferences. A survey was conducted on different routes attributes for variances drivers. Driver types were classified by gender, age, and driving career. Accordingly, a weight for road composition attribute such as number of lanes, number of accidents, slope was estimated by using Swing Weighting technique in Multi-Attribute Utility Theory. In addition, a case study was conducted and identified weights were applied to routes. In result, drivers commonly prefer short route when they considered their routes. Also, male drivers prefer speedy and shorter route than that of female drivers. Elderly drivers prefer safe routes that represent low accidents rate. Moreover driving career under a year drivers prefer safe and easy routes. Therefore, we may conclude that the necessity of diversified route information is essential in the future car navigation system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.10a
• /
• pp.236-238
• /
• 2022

According to the current Road Traffic Act, the 2020 amendment bill is currently in effect as a system that designates vehicle types for each lane for the purpose of securing road use efficiency and traffic safety. When comparing the number of traffic accident fatalities per 10,000 vehicles in Germany and Korea, the number of traffic accident deaths in Germany is significantly lower than in Korea. The representative case of the German autobahn, which did not impose a speed limit, suggests that Korea's speeding laws are not the only answer to reducing the accident rate. The designated lane system, which is observed in accordance with the keep right principle of the Autobahn Expressway, plays a major role in reducing traffic accidents. Based on this fact, we propose a traffic enforcement system to crack down on vehicles violating the designated lane system and improve the compliance rate. We develop a designated lane enforcement system that recognizes vehicle types using Yolo5, a deep learning object recognition model, recognizes license plates and lanes using OpenCV, and stores the extracted data in the server to determine whether or not laws are violated.Accordingly, it is expected that there will be an effect of reducing the traffic accident rate through the improvement of driver's awareness and compliance rate.

• The Journal of Engineering Geology
• /
• v.23 no.3
• /
• pp.257-269
• /
• 2013

Prevention plans for landslide and slope disasters should be appropriate for a country's budget when considering a systematic investment plan. The systematic management of slopes adjacent to national highways should incorporate reasonable investment risk and the expected degree of damage should be calculated by considering the investment priorities. In terms of priority of investment, the major factors used to determine the degree of hazard are gradient, soil characteristics, RMR (Rock Mass Rating), stability interpretation, type of discontinuities, and history of collapse, among others. The likely consequences of slope failure can be determined by considering traffic volume, the number of lanes, and average vehicle risk. We performed such calculations regarding the priority of investment and performed a regression analysis for 392 slopes located in Yeongseo region, Gangwon province. The calculation results show that collapsed slopes have a higher priority for investment, as do slopes with a high proportion of dangerous sections and locations in valleys.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.6 no.3
• /
• pp.17-28
• /
• 2003

The objective of this study is to review and verify whether the functions and effect of roadside trees generally known in theory are actually realized in urban roads and how well they are performed if the function and effect are really realized. The study was conducted with a focus on air purification effect of roadside trees. The m헤r study result is as follows. First, calculation of air purification effect of roadside trees showed that it is minimal. However, 7.4 units of broad-leaved trees is necessary in order to purify $SO_2$ discharged by one passenger car and 1,803.3 trees to purify $NO_2$. Second, regarding pollutant absorption capacity, air pollutant absorption capacity increased as the number of rows planted gets higher (i.e., 2-row plantation absorbs pollutant better than I-row plantation). In particular, "2-row plantation + lower-level shrub + buffer green belt" was as eight times high as "I-row plantation" in absorption capacity. Third, out of 30 roads with over 8 lanes in 15 cities, only 33.3% or a total of ten roads in seven cities had a median strip. Out of these ten roads, nine roads were planted in a double-layer consisting forest trees, shrubs, ground plants (grass). Analysis showed that out of six tree species planted along these roads, about a half of them were weak to air pollution. Also, based on the outcome of this study, charging a "plantation due" when people purchase a new car, improving layout of roadside trees, and reinforcing plantation of air purification tree species when selecting tree species for roadside trees were proposed.

• International Journal of Highway Engineering
• /
• v.11 no.1
• /
• pp.47-58
• /
• 2009

Calibrating toll roads of highway networks needs additional weights within volume delay functions not like other general highway lints. However, current methods assigning additional weights in the volume delay function of toll roads are not sufficiently enough to predict real toll road volumes measured, since it does not consider discounting rates and an extra charges. This study develops methods to improve relevant and reliable volume delay functions. Suggested ideas include a method of weighting volume delay functions considering a value of time of vehicle types, a method of weighting volume delay functions considering lane distributions of vehicles, and a method of weighting volume delay functions considering percentages of link lengths per a number of lanes of toll roads. It is found that the method of weighting volume delay functions considering lane distributions of vehicles show most reliable and appropriate results, while the first method shows overestimation and the third method does underestimation of highway link volumes. In terms of assignment methods, total OD equilibrium assignment shows better results than PCU based assignment.

• International Journal of Highway Engineering
• /
• v.18 no.6
• /
• pp.69-76
• /
• 2016

OBJECTIVES : The objective of this study is to propose a capacity analysis methodology for riverside bike-exclusive roads. METHODS : Three steps were performed to develop a methodology to estimate bikeway capacity. First, we reviewed previous studies on the vehicle-road capacity analysis and proposed their applicability to bikeways. Second, two assumptions were made based on the traffic flow characteristics of bikeways: (1) the capacitated state in bikeways occur within a bicycle platoon, and (2) a bicycle platoon consists of more than three bicycles running in close proximity. In addition, it is assumed that the mean time headway of a bicycle platoon represents the characteristics of the platoon. The normality of the mean-time headway of a bicycle platoon calculated using the central limit theorem leads to the development of a method that estimates the riverside bikeway capacity using data collected from two different riverside bike-exclusive roads (Han-river and Anyangcheon). We used a location-fixed video camera to record videos of running bicycles and wrote a special-purpose software program to code the time-headway data from the videos. RESULTS : Time headways from 189 bicycle platoons were analyzed. The estimated mean-time headway of the capacitated bicycle flow is 1.01 s, from which the capacity of the bikeway is found to be 3578 vehicles/h. CONCLUSIONS : The proposed method that estimates bikeway capacity could be applicable to the analysis of short-range congested area rather than planning the number of lanes. In other words, it determines the sections that are temporarily highly congested and proposes appropriate strategies to mitigate the congestion.

• Computers and Concrete
• /
• v.19 no.6
• /
• pp.725-736
• /
• 2017

This paper presents the two-, three-, and four-lane transverse reduction factor based on FEA method, probability theory, and the recently actual traffic flow data. A total of 72 composite girder bridges with various spans, number of lanes, loading mode, and bridge type are analyzed with time-varying static load FEA method by ANSYS, and the probability models of vehicle load effects at arbitrary-time point are developed. Based on these probability models, in accordance to the principle of the same exceeding probability, the multi-lane transverse reduction factor of these composite girder bridges and the relationship between the multi-lane transverse reduction factor and the span of bridge are determined. Finally, the multi-lane transverse reduction factor obtained is compared with those from AASHTO LRFD, BS5400, JTG D60 or Eurocode. The results show that the vehicle load effect at arbitrary-time point follows lognormal distribution. The two-, three-, and four-lane transverse reduction factors calculated by using FEA method and probability respectively range between 0.781 and 1.027, 0.616 and 0.795, 0.468 and 0.645. Furthermore, a correlation between the FEA and AASHTO LRFD, BS5400, JTG D60 or Eurocode transverse reduction factors is made for composite girder bridges. For the two-, three-, and four-lane bridge cases, the Eurocode code underestimated the FEA transverse reduction factors by 27%, 25% and 13%, respectively. This underestimation is more pronounced in short-span bridges. The AASHTO LRFD, BS5400 and JTG D60 codes overestimated the FEA transverse reduction factors. The FEA results highlight the importance of considering span length in determining the multi-lane transverse reduction factors when designing two-lane or more composite girder bridges. This paper will assist bridge engineers in quantifying the adjustment factors used in analyzing and designing multi-lane composite girder bridges.

• Journal of Korean Society of Transportation
• /
• v.34 no.6
• /
• pp.499-509
• /
• 2016

The pedestrian traffic flow has more complicated microscopic features than vehicular traffic flow. Without any designated lanes or any guidance, pedestrians naturally move and change their routes in two dimensional domain with ease. Thus the assessment of pedestrian comfort level should be considering the microscopic features of pedestrian flow. This study is aimed at developing pedestrian comfort criteria based upon pedestrian flow simulation model. This study suggests three criteria to determine pedestrian comfort level; the deviation of route, the acceleration of walk, and the number of collision. Each criterion, which can address the unique walking patterns of pedestrian flow, is represented as each different function with respect to traffic flow rate. The criteria can be the additional indicators to determine the level of service of pedestrian flow together with traffic flow rate and walking speed.

• International Journal of Highway Engineering
• /
• v.12 no.2
• /
• pp.63-69
• /
• 2010

Since speed limit enforcement in school zones is the most important to reduce the occurrence of severe child related accidents, school zones typically have a speed limit of 30km/h. However, it is found that the majority of vehicles passing school zones are traveling over 30km/h. This indicates that school zones are not being effectively operated to achieve the main objective which is the reduction of child related accidents. This study aims to identify the factors affecting the violation of speed limits in school zones through the results of field survey from 8 elementary schools. The results showed that time period, the number of lanes, the width of sidewalks, and the status of colored pavement were found to be highly associated with the violation of speed limits in school zones at the 95% significance level. The results of this study may provide some insights for making safe environments around schools.