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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Korean Society of Transportation
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Korean Society of Transportation
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Volume & Issues
Volume 19, Issue 6 - Dec 2001
Volume 19, Issue 5 - Oct 2001
Volume 19, Issue 4 - Aug 2001
Volume 19, Issue 3 - Jun 2001
Volume 19, Issue 2 - Apr 2001
Volume 19, Issue 1 - Feb 2001
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Development of Automatic Incident Detection Algorithm Using Image Based Detectors
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 7~17
The purpose of this paper is to develop automatic incident detection algorithm using image based detector in freeway management system. This algorithm was developed by using neutral network for high speed roadway and by using speed and occupancy variable for low speed roadway. The image detector system with the developed automatic incident detection algorithm can detect multi-lane as well as several detect areas for each lane. To evaluate this system, field tests to measure the detecting rate of incidents were performed with other systems which have APID and DES algorithm at high speed roadway(freeway) and low speed roadway(national arterial). As the results of field test, it found that the detect rate of this system was highest rate comparing to other two systems.
A Study of Architecture for national Intelligent Transportation Systems (Methodology and Model)
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 19~31
In this paper, 3 layered architecture model and related design guidelines are proposed, which have been actually applied in our national ITS-Architecture design. The domain architecture as the 1st layer is to structure all ITS related domains for maximizing the co-operability in national level. The logical architecture as the 2nd layer is to structure all ITS related application-systems for minimizing duplications, conflicts and dead-zones in service level and maximizing the co-operability in application-system level. The physical architecture as the 3rd layer is to structure all IT(Information Technology) related physical resources for maximizing.
A psychological study of determinant factors on drunk-driving judgements
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 33~47
The purposes of this study are (a) to investigate which cognitive and psychological factors heavily influence on drunk-driving. (b) to examine the group difference between drink drivers and non-drink drivers on these factors. A total of 136 adult drivers (male= 122, female=13) were shown a checklist composed of factors that have an effect on drunk-driving. Based on the analysis, it identifies that drink drivers consider four factors into more important drunk-driving judgement factors than any others. More specifically, four factors are amount of drinking, passing time after drinking, discomfort moving without car and distance to home. Compared the means of drink drivers to that of non-drink drivers in each factors, this analysis also shows significant differences between drink drivers and non-drink drivers. 1) Drink drivers are less likely to aware possibilities of being in an accident and of being arrested for drunk-driving than non-drink drivers. 2) Drink drivers overestimate their driving ability while drunken. 3) Drink drivers are more sensitive to discomfort moving without car and distance to home. Finally, 4) drink drivers are more likely to underestimate amount of drink they consumed.
Principles for Government Involvement in Urban Logistics Planning
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 49~63
The pattern of urban transport activity has two major components: the movement of people and the movement of goods. Roads in urban areas carry large number of trucks laden with goods that support urban economy and lifestyle. Therefore urban goods movement plays a vital role, but at the same time, urban goods movement are an important source of congestion, and a major contributor to the adverse environmental and social impacts of urban transport. In addition, the demand for goods movement is growing at a faster rate than personal travel in many cities, due to changes in industry logistics and consumer purchasing patterns. As a result, the significance of urban freight activity is increasing in terms of both its role in urban economy and its adverse impacts on urban amenity. This study is focused on the role and involvement scope of metropolitan government in urban logistics aimed at increasing its efficiency and reducing its negative impacts. The major suggestions of this study are (a) development of a measure of urban goods movement activity, (b) evaluation of data requirements and availability, (c) dialogue between the public sector and private sector, and (d) the role of metropolitan government.
The AADT estimation through time series analysis using irregular factor decomposition method
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 65~73
Until recently, we use only weekly and monthly adjustment factors in order to estimate the AADT. By the way. we can suppose that the traffic is time series data related to flow of time. So we tried to analyse traffic patterns using time series analysis and apply them to estimate the AADT. We could divide traffic patterns into trend, cyclic variation, seasonal variation and irregular variation like as time series data. Also, in order to reduce random error components, we have looked for the weather conditions as an influential factor. There are many weather conditions such as rainfalls, but, temperatures, and sunshine hours among others but we selected rainfalls and lowest temperatures. And then, we have estimated the AADT using time series factors. To compare the results of, we have applied both irregular variation joined to weather factors and that not joined to. RMSE and U-test were opted at methods to appreciate results of AADT estimation.
An Empirical Study on Evaluating the Value of Port
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 75~87
Inter-port competition is fiercer than in the past because of technological evolution in transport systems : the increasing side of containerships implies only a few calls in three or four ports at each end of the trade and the rest of the traffic being served by smaller feederships. It is therefore essential for big ports to be selected as one of these calls by the main shipowners, consortia and alliances to avoid rmarginalisation. In order to compete effectively, many ports have been obliged to modernise and extend considerably its existing ports or to build new port facilities. With the advent of major environmental legislation around the world, however, amenities such as fish and wildlife, clean air and water, access to the waterfront, and view protection took on greater importance. Ports are now being forced to incorporate environmental considerations into their planning and management functions in order to avoid additional costs or timing delays. The aim of this paper is to analyse the port value by which port comparison(or selection) will be made with HFP(Hierarchical Fuzzy Process) method. This was done by extracting and grouping the evaluation factors of port value by port experts : facility and location factor, logistics service factor environment and amenity factor, city and economic factor, and human and system factor. For empirical test of this method, 6 major ports in Northeast Asia were chosen and analysed. The order of importance for five evaluation factors were 1) facility and location factor 2) logistics service factor 3) human and system factor, 4) city and economic factor, and 5) environment and amenity factor. This means that geographical location and logistics services are still being considered as the most important factor to call the port by port users. even though environment and amenity factor shows relatively low figure. Among 6 major ports, Port of Kobe was ranked the first position in a comprehensive evaluation, while Ports of Busan and Kwangyang were 4th and 5th respectively. This implies that Port of Busan should make much efforts to enhance the existing facilities as well as management system.
Economies of Scale and Scope In Seoul's Urban Bus Industry
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 89~102
Using a multiproduct translog cost function model, this paper examines the existence or absence of scale and scope economies in Seoul's urban bus industry. The Paper then conceptualizes that the bus firm produces three outputs (city, seat and local bus-kilometers) using low input factors(labor, capital, fuel and maintenance). Using 1996 annual observations for 81 Seoul's bus firms, the equation system consisting of a cost function and three input share equations is estimated with the nonlinear iterative Zellner method. The findings show that the cost function corresponding to a non-homothetic production technology with separability between local bus outputs and inputs adequately represents the structure of cost for Seoul's bus firms, and that the demand lot all input factors is quite inelastic with respect to their own price. On the other hand, nearly all firms experience mild overall economies or scale, but rather marked product-specific economies of scale with respect to all the three outputs. In addition, there appear to be substantial economies or scope associated with the joint production of city and seat bus services, while considerable diseconomies of scope associated with that of city and local bus services. These results indicate that the merger of smaller firms into larger firms with a fleet of approximately 200 buses would result in more cost-efficient bus services.
A Study of Improving Methods for The Performance of Freeway Incident Detection Algorithm
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 105~118
Incident detection rate and false alarm rate are the key measures tot estimating the performance of automatic incident detection algorithms. It is, however inherently very difficult to improve the two measures simultaneously. The main purpose of this study is to present some methods for solving the problem. For this, an incident detection algorithm has been designed in this study. The algorithm is consisted of two functions, one for detecting incident and another for detecting congestion. A logic for distinguishing non-recurrent congestion from recurrent congestion was employed in the algorithm. The new algorithm basically requires speed, flow, and occupancy data for defining incident situation, but the algorithm is able to perform this task without one of the three parameters. The performance of the algorithm has been evaluated by using the field data collected from Interstate Highway 880 in Bay Area, California. The empirical analysis results are very promising and thus, the algorithm proposed may be very useful for the analysts. This paper presents some empirical test results for the performance of California incident detection algorithm, only for the reference purpose.
Development of Truck Performance Curves for Upgrade on Highways
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 119~129
The purpose of this study is to estimate the parameters of truck speed prediction model which are considered truck characteristics, road conditions and driving resistances in korea. First, the typical truck is selected by using the cumulative distribution of weight to power ratio which is adjusted for the gross weight of the truck of which the towing capacity is 11tons or more. Second, the entering speed of upgrade road section is analyzed by the data observed in the median lane of four-lane and two-lane highways selected level-straight section. The truck crawl speed prediction model is arranged in order to develop the truck speed prediction model. Truck gross weight(W), engine power(P), vertical grade(G) are set up as the independent variables, and the optimization are carried out to find parameters k,
. And, the data(gross weight, engine power, crawl speed, vertical grade) of the truck on the crawl speed collected from field survey is used in finding the parameters. Finally, the truck performance curves are illustrated by using the estimated parameters.
The performance of OD estimation from link traffic counts in varying OD matrix structure
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 131~142
Previous OD matrix estimation methods from link traffic counts have focused on the formulation of mathematical model and its solution algorithm. Thereby those methods have assumed that true or real OD is similar to the target OD and paid little attention to the properties of the change of OD structure. Although it is general situation that each OD pair increases or decreases due to significant land use and to large time variation between target OD with real OD, those methods have set unrealistic assumptions that target OD increases or decreases uniformly and that the OD structure does not change. Therefore those methods have showed poor performance of OD estimation in general situation. To cope with the problem. this paper suggests a new concept of OD matrix structure and shows the shortcomings of previous method′s dependancy on target OD matrix. We divide "OD trips" into "OD scale" and "OD structure". Where OD scale is a quantitative magnitude of OD trips and "OD structure" is ordinal OD scale. This paper use the same solution algorithm developed by Baek et al. (2000) for analysing the OD structure. Results of numerical examples show that the performance of the method is better than that of previous methods, while the previous methods have better performance in estimation only when OD trips increase or decrease. In addition to, if OD structure does not change, the results show that the error of estimation is low relatively regardless of the large difference of trips between target OD and real OD. This paper also shows that the model performance on OD structure and on OD trips is low as the number of origins that OD structure is changed increase. From the results we suggest that the change of OD structure can be more important information than the difference between target OD and real OD in OD estimation steps.
Development of a Micro-Simulator Prototype for Evaluating Adaptive Signal Control Strategies
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 143~160
Micro-simulation models have been recognized as an efficient assessment tool in developing traffic signal control technologies. In this paper a prototype of a microscopic simulation model which can be applied to evaluate the performance of traffic-adaptive signal control strategies was developed. In the simulation process, space-based arrays were appled to estimate parameters of car following and lane changing models. Two levels of link types, a micro-type and macro-type links, were also embodied in the simulation process. The proposed model was tested on a test network consists of 9 intersections. The performance of the proposed model was evaluated in link by link comparisons with the results of NETSIM. The results show that the proposed model could appropriately simulate traffic flows of the test network. The model also produces traffic adaptive signal timings, cycle lengths and green times for turning movements, based on the detector data. It implies that the optimization process of the model produces reasonable signal timings for the test network on the cycle basis.
A Study On the Image Based Traffic Information Extraction Algorithm
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 161~170
Vehicle detection is the basic of traffic monitoring. Video based systems have several apparent advantages compared with other kinds of systems. However, In video based systems, shadows make troubles for vehicle detection. especially active shadows resulted from moving vehicles. In this paper a new method that combines background subtraction and edge detection is proposed for vehicle detection and shadow rejection. The method is effective and the correct rate of vehicle detection is higher than 98(%) in experiments, during which the passive shadows resulted from roadside buildings grew considerably. Based on the proposed vehicle detection method, vehicle tracking, counting, classification and speed estimation are achieved so that traffic information concerning traffic flow is obtained to describe the load of each lane.
On-Line Travel Time Estimation Methods using Hybrid Neuro Fuzzy System for Arterial Road
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 171~182
Travel Time is an important characteristic of traffic conditions in a road network. Currently, there are so many road users to get a unsatisfactory traffic information that is provided by existing collection systems such as, Detector, Probe car, CCTV and Anecdotal Report. This paper presents the results achieved with Data Fusion Model, Hybrid Neuro Fuzzy System for on - line estimation of travel times using RTMS(Remote Traffic Microwave Sensor) and Probe Data in the signalized arterial road. Data Fusion is the most important process to compose the various of data which can present real value for traffic situation and is also the one of the major process part in the TIC(Traffic Information Center) for analyzing and processing data. On-line travel time estimation methods(FALEM) on the basis of detector data has been evaluated by real value under KangNam Test Area.
Multiple Path-Finding Algorithm in the Centralized Traffic Information System
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 183~194
The centralized traffic information system is to gather and analyze real-time traffic information, to receive traffic information request from user, and to send user processed traffic information such as a path finding. Position information, result of destination search, and other information. In the centralized traffic information system, a server received path-finding requests from many clients and must process clients requests in time. The algorithm of multiple path-finding is needed for a server to process clients request, effectively in time. For this reason, this paper presents a heuristic algorithm that decreases time to compute path-finding requests. This heuristic algorithm uses results of the neighbor nodes shortest path-finding that are computed periodically. Path-finding results of this multiple path finding algorithm to use results of neighbor nodes shortest path-finding are the same as a real optimal path in many cases, and are a little different from results of a real optimal path in non-optimal path. This algorithm is efficiently applied to the general topology and the hierarchical topology such as traffic network. The computation time of a path-finding request that uses results of a neighbor nodes shortest path-finding is 50 times faster than other algorithms such as one-to-one label-setting and label-correcting algorithms. Especially in non-optimal path, the average error rate is under 0.1 percent.
Analysis of Critical Time Headway and Capacity for Freeway Merging Area
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 195~205
The objective of the paper is to analyze the traffic characteristics for freeway merging area. Freeway merging area is different from basic section due to ramp vehicles. Therefore, to understand the traffic characteristics of (leeway merging area, this study focused on two factors including critical time headway required in merging maneuver and maximum possible merging volume. In this paper, new model that adopts critical time headway instead of critical time gap in calculating the maximum possible merging volume based on probability function was developed In previous studies, for calculating the maximum possible merging volume, it was considered that merging vehicles could merge freely if a given time gap was greater than the critical time gap. Also, the critical time gap was used as the same value in all traffic flow conditions. But, a time gap required in merging maneuver could be changed, even to the same driver, because difference of relative speed varies in different traffic flow conditions. So, in some cases, the critical time gap could be insufficient value in merging maneuver. Therefore, in this study. a calculating procedure for critical time headway in all traffic flow conditions was presented. Also, the maximum possible merging volume and capacity for freeway merging area were calculated by using the previously found critical time headway.
Development and Application of Traffic Accident Forecasting Model for Signalized Intersections (Four-Legged Signalized Intersections In Kwang-Ju)
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 207~218
As a city and industries are developed rapidly, a traffic accident and congestion take places on the road link become serious and it can be a large problem of the society in the future. Especially, most of the traffic accidents on the signalized intersection are caused by the human factor, vehicle and environmental factor mutually. The relation of the traffic accident and volume is acting on the outbreak of the traffic accident and the mistake of driver altogether as a major cause. The purpose of this paper is to develop a model for the forecasting of the traffic accident and to use research data gained to predict many traffic accidents. The data of this study were used with real one of the 73 areas of the four-legged signalized intersection in Kwang-ju city from 1996 to 1998 for three years to develop a model for the forecasting of the traffic accident. The statistical methods used in this paper are the principal component, regression and correlation analysis. We studied accident models to find out useful data from the statistics method and applied the data to the different area of the Choun-La province for the verification of the model. So, the result of this paper showed a reasonable model for the forecasting or the traffic accident and possibility of the model for simulating on real case. Finally, This study would be made of a study continually for the safe design and plan for the four-legged signalized intersection.
Development of a traffic simulation model analyzing the effects of highway incidents using the CA(Cellular Automata) model
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 219~227
In this study, the simulation was constructed using CA(Cellular Automata) rule to analyze the effect of incidents, which was verified using real-time VDS data and data collected on the field. The study analyzed the effect of incidents on highways by the simulation. The result appears to be statistically available with 5% of significance level. In order to analyze the effect of incident, the study classified time period of incidents and types of incidents in relation with traffic volume. Also, the effect of each type of incidents was analyzed in terms of time difference in sectional travel and delay time. In conclusion, little effect of incidents on traffic flow is noticed with light traffic volume but it becomes serious as the traffic volume increases. In addition, the delay happens to appear without incidents as the traffic volume increases over 2000 veh/hour. Also, when incidents happened during 45 minutes, the delay was about 425-722 veh·hour.
A Study on Taxi Revenue Analysis in Seoul
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 241~251
Econometric analysis of the effect of roadway geometric and roadside features on run-off-roadway accident frequencies and severities
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 255~256
Analysis of Traffic Actuated Signal Control Strategies at Urban Diamond Interchanges
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 257~257
A Study on Planning Methodology of Location and Management for Loading/Unloading Facilities on CBD
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 258~259
An International Comparative Analysis of the Characteristics of Energy Consumption, Accessibility and Mode Choice by Density between Compact City and Sprawl City (In the case of Korea's Songnam and Japan's Fukuoka)
Journal of Korean Society of Transportation, volume 19, issue 6, 2001, Pages 260~261