• Journal of Korean Society of Transportation
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• v.24 no.7 s.93
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• pp.65-79
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• 2006

The ATIS(Advance Traveler Information System), as one part of ITS, is a system aiming to disperse traffic volume on transportation networks by providing traffic information to transportation users on pre-trip and en-route trips. One of tools in ATIS is usage of VMS(Variable Message Signs). It provides to the drivers with direct information about state of processing direction. which is considered as the most effective method in ATIS. The purposes of providing VMS information are classified two categories. One is to provide simple information to drivers for their convenience. The other is to manage traffic demand to improve transportation network performance. However, for more effective and reliable VMS information, several strategies should be taken into account. The main VMS management strategy is "Traffic Diversion Strategy for minimum delay" when traffic congestion or incident are occurred. For effective operation. firstly. reasonable diversion traffic volume is determined by network traffic condition Secondly, it is necessary to make providing information strategy which reflects driver response behavior for controling diversion traffic volume. This paper focuses on the providing real-time route guidance information by VMS when congestion is occurred by the incidents. This sturdy estimates time-dependent system optimal diversion rate that inflects travel time and queue lengths using traffic flow simulation model on base Cellular Automata. In addition, route choice behavior models are developed using binary logit model for traffic information variable by traffic system controller. Finally, this study provides time-dependent VMS massage contents and degree of providing information in order to optimize the traffic flow.

• Journal of Korean Society of Transportation
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• v.29 no.3
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• pp.61-72
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• 2011

In the benefits of ITS, there are intangible gains from real-time traffic information as well as classical gains such as travel time saving. These intangible gains are difficult to be estimated by existing transportation investment appraisal commonly used in SOC investment. The major reason is not because of the absence of methodology but because of the absence of generalized values of particular benefits from real time traffic information. This research explores the value of real-time traffic information on VMS that is the most representative of ITS services, by using CVM with Double Bounded Dichotomous Choice Question. Willingness-To-Pay (WTP) functions of drivers are built with survival functions using various types of probability distribution functions such as Exponential, Log-logistic, and Weibull functions. The results reveal that Log-logistic distribution is the most appropriate distribution model to estimate WTP, and the estimated coefficients are stable through LR (Likelihood Ratio) test. For the further study, it is recommended to perform statistical tests of temporal and spatial transferability that is not examined in this research due to the lack of data.

• Journal of Korean Society of Transportation
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• v.25 no.6
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• pp.111-120
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• 2007

More accurate vehicle trajectory data are now readily available through Differential Global Positioning Systems (DGPS). A variety of research opportunities emerge with utilization of such high resolution traffic data. A novel approach of this study is to explore drivers' responsive behavior to variable message signs (VMS) by using individual vehicle trajectories extracted from in-vehicle DGPS data. Responsive characteristics of drivers traveling on urban freeways, which can be represented by speeds and acceleration rates, under the provision of real-time traffic information through VMS are statistically investigated. In addition to conducting an ANOVA test, probability density functions of acceleration rates were estimated. The findings of this study can be used to understand the impact of drivers' workload when providing VMS messages on traffic flow patterns. Furthermore, results can be important fundamentals to assist in conducting more realistic traffic simulations.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5D
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• pp.597-607
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• 2008

ATIS(Advanced Traffic Information System) provide valuable information as the travel time and traffic congestion, detour, traffic accident information to drivers, so it is being in the spotlight. But so far, the study on the consumer satisfaction with providing traffic information is incomplete. So, this study run a Canonical discriminant analysis and a Canonical correlation analysis by a QuantificationIItheory based on a Traffic Information Satisfaction image data through questionnaires, and found out the factors with influence on the consumer satisfaction. And this study definitely found out the correlation between consumer's recognition and traffic information satisfaction through understanding the change on the recognition about traffic information satisfaction by a QuantificationItheory. Finally, this study found out the change on the sensibility recognition of drivers by running the principal component anlysis, developed the traffic information satisfaction evaluation model considering the change on the recognition by using the structural equation model.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.4
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• pp.1-13
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• 2009

VMS(Variable Message Sign) which makes the traffic flow smooth by providing traffic information to road users in real-time has been being installed or operated on the road as part of the detailed ITS system. However, some problems were found as a result of survey on express way currently. In the part of the phase operation, the message interpretation time wasn't defined so that the phase operation was difficult. In the part of the information service, not considering characteristic of the VMS section caused the confusion to drivers. In the part of the message exposure, font, alignment, conversion and composition of the information were not consistent and use of superfluous words and inconsistent use of word having the same meaning brought about the problem on information communication This study established the detailed exposure method based on instructions relative to VMS operation. The method established by defining the number of appropriate phase and setting required function of each individual VMS installation location. The method is as follow. the font type is the GULIM, the message conversion method is simple conversion method, the alignment method is centering alignment method and the color is defined according to each situation. In this study, the preference survey was performed to review the validity of the proposed improvement through the common driver. The results were similar with the pre-study except for the font type. This study established the detailed exposure method based on instructions relative to VMS operation. The method established by defining the number of appropriate phase and setting required function of individual VMS installation location. For the evaluation of status and improvement, preference survey of ordinary drivers and statistics analysis was carried.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.4
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• pp.36-48
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• 2008

Variable Message Signs(VMS) is one of the important subsystems of Intelligent Transportation Systems (ITS), which is useful for providing drivers with real-time information on traffic, roadway or weather conditions. In order to maximize the effectiveness of the VMS system, it is required to reflect drivers's preference on designing and operating the system. In this context, this study was conducted to develop strategies to deliver the messages in an efficient manner while many other previous studies focused primarily on the contents of the messages, from drivers's perspectives. Drivers's preference on message expression formats and message display orders were investigated through image analysis in the perspectives of a total of 40 subjects. With respect to message expression formats, drivers preferred Gulim or Dodum in font style, middle arrangement of the letters, pictogram combination as opposed to letters only, blank time less than 0.5 sec, appearing message in animation effect, messages in single phase, non-flashing message. In the matter of message display orders, drivers preferred to obtain link or traffic information in the lust place. Then, they desired to be informed of roadway condition and instructions or recommendations for drivers to cope with unexpected events among various messages for traffic condition.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.3
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• pp.52-61
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• 2020

This study developed a legibility distance(LD) model for three colors used in VMS according to luminance under foggy conditions through experiments. For this, a simulated environment was created, and LD values of red, green, and yellow color were collected by increasing the luminance. From the test results, the LDs for red at luminance levels of 2,000 cd/㎡ and 20,000 cd/㎡ and a visibility distance of 10m were 10.2m and 18.8m, respectively, which was an improvement of 84%. The LD was improved by 34% and 17% at a visibility distance of 20 m and 30 m, respectively. For green, the LD was improved by 69%, 63%, and 19% at visibility distance of 10m, 20m, 30m, respectively. For yellow, the LD was improved by 100%, 47%, and 36% at visibility distance of 10m, 20m, 30m, respectively. The LD models for three colors were developed by using two independent variables, luminance value and visibility distance. The adjusted coefficients of the red, green, and yellow model equations were calculated as 0.982, 0.978, and 0.915, respectively, and the explanatory power of all models was very high.

• International Journal of Highway Engineering
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• v.7 no.4 s.26
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• pp.151-162
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• 2005

Variable Message Sign (VMS), which provides drivers with direct information about state of traffic congestion and for prevent an accident, is the most effective method among the methods of providing information in Advanced Transportation Management System. Currently establishment and the VMS which is operated foundation lets in Guidelines on the use of Variable message sign (a book of the VMS) of 1999 November the Ministry Construction & Transportation, these contents mean main viewpoint on physical part such as message special quality variable (font, character size and line space, word interval) and position mainly among standard about establishment in general. But, it is true that using without effect verification on the character of VMS display and that using mode of stationary-centered. In this paper, it executed significance test to effort verification on the character of VMS display for more practical and effective information transmission based on the driver viewpoint For the researches; develop 3D-Simulation, select characteristics of driver's visual cognition behavior (the conspicuity, the legibility and the comprehensibility), evaluation each issue (day or night, 80km/h or 100km/h). Especially, that used the Eye Marker Recorder to measure of reading-time (legibility) thus, confirmed objectivity and reduce an observational error. The results showed that the conspicuity is Flashing> Stationary>Scroll. The legibility is not deference that Flashing between stationary form. Also the comprehensibility result showed that Flashing> Stationary>Stroll form.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.3
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• pp.11-19
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• 2009

At present, an intelligent transport system (ITS) is being actively introduced as an alternative plan to solve various transport problems, and a traffic information provision service, a field of ITS, is being provided to users through diverse media. However, the evaluation of how useful the traffic information provided to the road users is limited to a simple questionnaire, and the systematic evaluation about what factors affect the usefulness of traffic information has not been realized. Therefore, it is impossible to calculate user convenience occurring due to traffic information, This paper aimed to develop an index to evaluate user satisfaction levels with traffic information and develop a user satisfaction level model. A result of establishing a user satisfaction level model by executing a questionnaire survey for the analysis object of variable message sign (VMS), a representative information provision medium, showed that 'desire satisfaction', 'trust', 'understanding', and 'efficiency' have an effect. Of them, the 'understanding' showed the highest level, so it was seen that, in case of VMS, how easily the character, figure, expression, etc. provided in the information was understood by users has the biggest effect on the satisfaction level of the information. The next levels of effects on the satisfaction was in the order of 'user trust', 'efficiency', and 'desire satisfaction'.

• The Journal of the Korea Contents Association
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• v.22 no.10
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• pp.526-534
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• 2022

In August 2014, the Ministry of Land, Infrastructure, and Transport (MOLIT) devised an innovative ITS measure in which private and public sectors share roles to maximize investment efficiency and effectiveness in collecting and offering traffic information that had been separately implemented by the state and private sector. The main details of the innovative measure include the following: For communication information, the information collected by the private sector is used, and the state concentrates on safety-related information collection, such as unexpected situations, including construction, accidents, and deteriorating weather conditions. Consequently, safety-related information is offered in real-time through smartphones and navigation, in addition to electric road signs that have limitations in providing unexpected real-time situations due to installation at specific spots. This study presented a connected traffic information priority coordination plan to improve the accuracy of traffic information offering by analyzing problems of related traffic information, including a general national highway case study to enhance the efficiency of national highway ITS implementation, according to actual public-private traffic information sharing. In addition, this study reviewed whether to operate or demolish the information collection equipment by analyzing traffic volume level and availability of related traffic information in the existing ITS operation sections and presented ITS collection equipment installation judgment standards based on the cases concerned.