• Proceedings of the KOR-KST Conference
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• 2007.05a
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• pp.319-326
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• 2007

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6D
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• pp.927-933
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• 2006

The Variable Message Signs (VMS) are useful way to reduce the socio-economic costs due to the traffic congestions and delays by providing the information on traffic condition to drivers. This study provided a methodology to determine the locations of VMS's in terms of the minimization of the delay by applying the genetic algorithm. The optimal number of VMS's was also derived by the economic analysis based on the cost and the benefit. The simulation considered the variation of traffic volume, the frequency and duration of the incident, and the traffic conversion in order to reflect the real situation. I've made a scenario to consider traffic volume and incident, and it can undergo through changing different traffic volume and incident in time and days and seasons. And I've comprised two kinds of result, one is based on empirical studies, the other is based on Genetic Algorithm about optimal allocation VMS. This result of using optimal location VMS, reduce total travel time rather than preceding study based on normal location VMS and we can estimate optimal location VMS each one.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.4
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• pp.125-144
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• 2022

When a variable message signs (VMS) system displays false information related to traffic safety caused by malicious attacks, it could pose a serious risk to drivers. If the normal message patterns displayed on the VMS system are learned, it would be possible to detect and respond to the anomalous messages quickly. This paper proposes a method for detecting anomalous messages by learning the normal patterns of messages using a bi-directional generative pre-trained transformer (GPT) network. In particular, the proposed method was trained using the normal messages and their system parameters to minimize the corresponding negative log-likelihood (NLL) values. After adequate training, the proposed method could detect an anomalous message when its NLL value was larger than a pre-specified threshold value. The experiment results showed that the proposed method could detect malicious messages and cases when the system error occurs.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.1
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• pp.13-27
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• 2012

According to the development of Intelligent Transportation System technology, VMS(Variable Message Signs) are operating on highway. But, VMS display information which don't reflect traffic condition and driver's human factor. So driver can't read VMS message during limited time, it makes to reduce VMS's reliability. This paper presents a model for VMS message reading time and distance considering traffic condition and human factor. We built driving simulator by Winroad package which is able to copy real driving condition. Subjects were comprised of 20 people who reflect domestic driver's condition such as sex. We did regression analysis with experiment results and draw the model. The model could be possible to develop message- set considering traffic condition and human factor.

• International Journal of Highway Engineering
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• v.13 no.4
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• pp.231-238
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• 2011

Variable message signs(VMS) in use are being displaying with the LED device as the luminous source, and it is a recent trend to be changed from the Lamp type to the Surface-Mount Devices(SMD) type. The LED device leads to get VMS display brightly and clearly, leading to have visibility and legibility better than the existing VMS. However, the lights which display off the road, the unnecessary energy, might have negative effect on ecosystem. This study developed the way of getting the lights be displayed only to drivers without the unnecessary energy and estimated the energy efficiency of the development by the optical testing. As a result, this study showed that the energy consumption of the developed display device appeared to decrease by about 36.1% compared to the existing device. Also the upward and downward angle of the lights changed from an angle of $24^{\circ}C$ to $0^{\circ}C$and from an angle of $-24^{\circ}C$ to $-11^{\circ}C$, respectively. Therefore, it anticipates that the developed device would benefit highway safety due to an improvement in visibility and legibility compared to the existing VMS and the energy consumption would be less lower than the existing VMS.

• Journal of Korean Society of Transportation
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• v.25 no.3
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• pp.99-109
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• 2007

Variable message signs (VMS), which are used for providing real-time information on traffic conditions and accident occurrences, are one of the important components of intelligent transportation systems VMS messages need to meet human factor requirements: messages should be readable and understandable while driving. Lab-controlled experiments on VMS messages were conducted to obtain useful data for analyzing drivers' responsive characteristics for VMS messages. Binary logistic regression (BLR) modeling techniques were applied to explore the relationships among drivers' message perceptions, message reading time, and amount of VMS messages. Probabilistic outcomes of the proposed BLR-based perception model could be greatly utilized to design VMS messages considering drivers' legibility performance. The major contribution of this study is to develop invaluable statistical models that can be used in designing VMS messages more effectively from the human factor point of view. The results could be further applied to establish the scheme of VMS message phase and duration.

• Journal of Korean Society of Transportation
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• v.25 no.5
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• pp.23-32
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• 2007

Variable message sign (VMS), which is used for providing real-time information on traffic conditions and incidents, is one of the important components of intelligent transportation systems. VMS messages need to meet the requirements with the consideration of human factors that messages should be readable and understandable while driving. This study developed a legibility distance model for VMS messages using in-vehicle differential global positioning data (DGPS). Traffic conditions, highway geometric conditions, and VMS message characteristics were investigated for establishing the legibility model based on multiple linear regression analysis. The height of VMS characters, speed, and the number of lanes were identified as dominant factors affecting the variation of legibility distances. It is expected that the proposed model would play a significant role in designing VMS messages for providing more effective real-time traffic information.

• Journal of Korean Society of Transportation
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• v.26 no.1
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• pp.155-164
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• 2008

Variable Message Signs (VMS) is one of the major components for Intelligent Transport Systems (ITS) services that provides real-time traffic and incident information to drivers. The objective of this research was to develop a method determining the optimal location of VMS considering safety and driving characteristics of various drivers. A driving simulator was utilized to evaluate how drivers can safely exit to off-ramp depending on various VMS locations while information relating route diversion was provided. The binary logistic regression and factor analysis were applied in developing a probability model that predicts the success of safe off-ramp exiting. Based on the developed probability model, a method to estimate the spacing between VMS and off-ramp is suggested. It is expected that the products of this study would be utilized as a tool in determining VMS locations for ITS planners and designers.

• International Journal of Highway Engineering
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• v.17 no.5
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• pp.47-56
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• 2015

PURPOSES: The purpose of this study is to estimate the impact of variable message signage (VMS) on traffic safety as a function of road curve radius using statistical methods. METHODS: In order to analyze the impact of VMS installations on traffic safety, travel speed, lateral distance, and geometric data relating to road curvature in each study area was acquired and analyzed for the impact of providing VMS information on driver performance and traffic safety using statistical methods including student t-test, Mann-Whitney test, and the Anderson-Darling test for estimating traffic safety hazard zone in each lane. RESULTS: As a result of analyzing driver performance characteristics before and after providing VMS information, it was determined that by providing VMS information, mean travel speed is deceased and vehicles are driven with increased precision, following the centerline in the first and second lanes. Also the results of analyzing traffic safety impacts of VMS indicate that traffic safety performance factors in the first lane of the Gapyeong section can, on average, increase in the left and right side of the lane by 19.22% and 68.98%, respectively, and in the case of the second lane, safety impacts, on average, can increase in both sides by 100%. For the Hongcheon section, traffic safety impacts in the first lane, on average, can increase along the left and right sides of the lane by 32.31% and 47.18%, and within the second lane, traffic safety can be increased along the left and right side of the lane by 10.97% and -0.01%, respectively. CONCLUSIONS: Based on the results of this study, the impact on traffic safety obtained by providing VMS information for road sections with smaller curve radii is greater than can be obtained for road sections with larger curve radii.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.1
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• pp.89-99
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• 2018

The number of traffic accidents in Korea has been increasing since 2014. In most school zones, safety signs are installed to prevent children's traffic accidents. However, it has been known that the effects of those signs are not significant. A variable message sign(VMS), one of the components of Intelligent Transport System(ITS), has emerged as an alternative method. Therefore, this study examines relative effects of two different VMS messages(Timely vs. Continuous) on vehicle speed. Experiments were conducted in two school zones. 6,676 vehicles were measured for speed limit compliance. A counterbalanced multiple baseline design was adopted. The results showed that both types of message are effective in reducing the speed of vehicle. Specifically, A timely message was more effective in slowing down vehicle speed and improving speed limit compliance than a continuous message. The present study suggested that a VMS with human factors can be effective.