• Journal of Korean Society of Transportation
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• v.19 no.3
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• pp.75-88
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• 2001

Signal optimization model for alternative use of lanes at a signalized intersection with an stop-line added backward was presented in this paper. The simulation results shot-ed that the traffic fed from the stop-line passed the intersection in each specified phasing interval for left and through traffic. The experimental results indicated that the proposed model was much superior to traditional signal optimization methodology in reducing delay, fuel consumption, and disutility index for delay and stops. The effects for reducing delay were greater than those for doing fuel consumption and disutility index due to the added stop-line. The proposed model is expected to alleviate traffic congestion at intersections, both which have no left turn pocket, and which have large left turn volume. The model is recommended to adapted for intersections spaced long among them with no near driveway.

• Journal of the Society of Disaster Information
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• v.11 no.4
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• pp.597-606
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• 2015

Until now, u-turn lane installation methods have been studied variously. But, There is no specific standard yet. This study ranges are commercial area in Incheon metropolitan city through field investigation and presents specific design standard for efficient operation of left turn using a field data through calculating relevant permitted u-turn lane length and minimum separation distance from the front intersection to starting point of permitted u-turn lane in urban signalized intersections in commercial area. Relevant permitted u-turn lane length is found to be 32m and minimum separation distances from the front intersection to starting point of permitted u-turn lanes are 72m, 40m, 24m in case of 1 left turn lane, 2 left turn lanes and 3 left turn lanes respectively. By comparing result values and field data, they had a large difference under the similar situations in their lengths. This result is caused of no specific standard about design of u-turn lanes. If results of this study applied to design of u-turn lanes, signalized intersections in urban commercial areas would be operated more safety and efficiently.

• Proceedings of the KOR-KST Conference
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• 1999.10a
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• pp.223-228
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• 1999

• Journal of Korean Society of Transportation
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• v.22 no.4 s.75
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• pp.43-56
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• 2004

The KHCM procedure is a micro level analysis at signalized intersections requiring a lot of input variables and complex computations. The research was to investigate the possibility of simplifying the analysis procedures by using the generalized or the combined variables that less influence on the adjusted traffic volume and through-car equivalents of left or right turns. It was also tried to make lane grouping into directional flow ratio(v/s) based on a field surveys. The maximum and minimum values of each variables were compared with each other through the KHCM analysis procedures in terms of control delay. The lane grouping and the synthetical influence of a simplified method was evaluated with the scenario built in prevailing maximum and minimum conditions. The study showed that the control delay was not significantly sensitive to the selected variables and the lane grouping and their synthetical influence as well.

• Journal of Korean Society of Transportation
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• v.34 no.5
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• pp.449-464
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• 2016

The purpose of this study is to test applicability of cut-through roundabouts at a congested intersection and to provide the traffic volume ranges for theirs application. Various test scenarios were developed according to variation of total traffic volume, left-turn ratio to total traffic volume, and ratio of major road traffic volume to minor road traffic volume. In addition, three intersection types of cut-through roundabout, roundabout, and signalized intersection were compared with respect to delay times for each scenario, resulted from the simulation using VISSIM. In case of the ratio of major road traffic volume to minor road traffic volume, 6:4, the delay times of cut-through roundabout decreased up to 30% of left-turn ratio to total traffic volume for 400vphpl, up to 20% for 500vphpl, up to 10% for 600vphpl. In case of the ratio, 7:3, they are the same as 6:4 for 400vphpl, 500vphpl, and 600vphpl but they decreased up to 30% for 300vphpl and up to 10% for 700vphpl. In case of the ratio, 8:2, they are the same as 7:3 for 400vphpl, 500vphpl, and 700vphpl but they were reduced by 10% to 30% for 300vphpl and 20% for 600vphpl. It is concluded that the smaller left-turn ratio to total traffic volume as well as the ratio of minor road traffic volume to major road traffic volume is, the more effective in reducing delay times the cut-through roundabout is. Cut-through roundabouts can be expected to reduce delay times at a signalized intersections with traffic conditions above-mentioned.

• Proceedings of the KOR-KST Conference
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• 1999.10a
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• pp.211-216
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• 1999

• Journal of the Korea Society of Computer and Information
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• v.27 no.8
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• pp.69-75
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• 2022

In this paper, a method for predicting the speed for each lane from the link speed using an artificial neural network is presented to increase the accuracy of predicting the required time of a driving route. The time required for passing through a link is observed differently depending on the direction of going straight, turning right, or turning left at the intersection of the end of the link. Therefore, it is necessary to predict the speed according to the vehicle's traveling direction. Data required for learning and verification were constructed by refining the data measured at the Gongpyeong intersection of Gukchaebosang-ro in Daegu Metropolitan City and four adjacent intersections around it. Five neural network models were used. In addition, error analysis of the prediction was performed to select a neural network experimentally suitable for the research purpose. Experimental results showed that the error in the estimation of the time required for each lane decreased by 17.4% for the straight lane, 4.4% for the right-turn lane, and 3.9% for the left-turn lane. This experiment is the result of analyzing only one link. If the entire pathway is tested, the effect is expected to be greater.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.5 no.1 s.9
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• pp.21-30
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• 2006

For urban highway network, traffic control strategy paradigm has been shifted from the private auto-oriented to the public transit-oriented. Introduction of exclusive median bus lanes (EMBL) in Seoul, Korea, has especially accelerated such changes in transportation policy and thus highway environment. Left-turning movement treatment at signalized intersections where EMBL pass through has been emerged as one of the rising problems associated with a current signal head with 4-signal lens, the Korea standard. This study proposes a new signal phase operation scheme for signal operation at an isolated intersection where EMBL pass through. The authors propose to use of an exclusive bus signal head indicating right-of-way of transits on EMBL only. Based on it, three different phase operation scheme were developed for left-turn treatments for traffic control with (1) traffic responsive control mode and (2) time-of-day traffic control mode. In addition, methodologies to design and develop signal maps for the proposed signal phase schemes are also developed. The proposed operation can only be possible when additional uses of signal state relay boards are allowed.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.1
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• pp.13-21
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• 2015

This study focuses on operational analysis of 2 types of intersection shared lanes. First, the analysis showed that a through & right-turn shared lane is always less used than the adjacent through-only lanes and as a result, operational efficiency deteriorates. To improve the efficiency fine-tuning in signal timing optimization using lane-by-lane traffic volume data is required. Further improvement can be achieved by guiding drivers to equally use the shared lane. For left-turn & U-turn shared lanes, it was found that saturation flow rate is affected by interference between U-turn and conflicting right-turn movements. However, since such interference does not occur in every cycle, a statistical model must be established to develop realistic adjustment factor for saturation flow rate of the shared lane.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.5
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• pp.45-58
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• 2021

It is generally known that a two-lane roundabout has some problems in safety such as increasing conflicts, typically merging and diverging conflicts and conflicts between entering traffic and exiting as well as turning traffic. To solve these problems, a turbo-roundabout had been developed and has successfully brought safer and more efficient operation in other countries. In this study, micro simulations using VISSIM were conducted to investigate the maximum value of service traffic volume. It was found that operation of turbo-roundabouts was influenced by traffic volume for each turning traffic, and the maximum values of traffic volume were values between 2,400 and 2,800 vehicles per hour as rates of traffic volume for each turning traffic. Typically, turbo-roundabouts have limited to operate in conditions with more than 30% for left-turning traffic volume.