• International Journal of Highway Engineering
• /
• v.17 no.1
• /
• pp.91-98
• /
• 2015

PURPOSES : Although signalized intersections have been considered the best way to control traffic volume in urban areas for several decades, roundabouts are currently being discussed as an alternative way to control traffic volume, especially when traffic is light. Because a roundabout's efficiency depends on the load geometry as well as the traffic volume, design guidelines for roundabouts are recommended only if the incoming traffic volume is very low. It is rare to substitute a roundabout for an existing signalized intersection in urban areas. This study aims to estimate the benefits from the transformation of an existing signalized intersection into a roundabout in an urban area. When there is a more moderate volume of traffic, roundabouts can be effectively used by optimizing signals located at an approaching roadway. METHODS : The methodologies of this paper are as follows: First, a signalized intersection was analyzed to determine the traffic characteristics. Second, the signalized intersection was transformed into a roundabout using VISSIM microscopic traffic simulation. Then, we estimated and analyzed the effects and the performance of the roundabout. In addition, we adjusted a method to improve the benefits of the transformation via the optimization of signals located at an approaching road to control the incoming traffic volume. RESULTS : The results of this research are as follows: The signal-optimized roundabout improved delays compared with the signalized intersection during the morning peak hour, non-peak hour, and evening peak hour by 1.78%, 12.45%, and 12.72%, respectively. CONCLUSIONS : According to the simulation results of each scenarios, the signal-optimized roundabout had less delay time than the signalized intersection. If optimized signal control algorithms are installed in roundabouts in the future, this will lead to more efficient traffic management.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.10
• /
• pp.3858-3874
• /
• 2021

As an essential part of the urban transportation system, precise perception of the traffic flow parameters at the traffic signal intersection ensures traffic safety and fully improves the intersection's capacity. Traditional detection methods of road traffic flow parameter can be divided into the micro and the macro. The microscopic detection methods include geomagnetic induction coil technology, aerial detection technology based on the unmanned aerial vehicles (UAV) and camera video detection technology based on the fixed scene. The macroscopic detection methods include floating car data analysis technology. All the above methods have their advantages and disadvantages. Recently, indoor location methods based on wireless signals have attracted wide attention due to their applicability and low cost. This paper extends the wireless signal indoor location method to the outdoor intersection scene for traffic flow parameter estimation. In this paper, the detection scene is constructed at the intersection based on the received signal strength indication (RSSI) ranging technology extracted from the wireless signal. We extracted the RSSI data from the wireless signals sent to the road side unit (RSU) by the vehicle nodes, calibrated the RSSI ranging model, and finally obtained the traffic flow parameters of the intersection entrance road. We measured the average speed of traffic flow through multiple simulation experiments, the trajectory of traffic flow, and the spatiotemporal map at a single intersection inlet. Finally, we obtained the queue length of the inlet lane at the intersection. The simulation results of the experiment show that the RSSI ranging positioning method based on wireless signals can accurately estimate the traffic flow parameters at the intersection, which also provides a foundation for accurately estimating the traffic flow state in the future era of the Internet of Vehicles.

• Journal of Institute of Control, Robotics and Systems
• /
• v.18 no.8
• /
• pp.719-724
• /
• 2012

A traffic detection system is a device that collects traffic information around an intersection. Most existing traffic detection systems provide very limited traffic information for signal control due to the restriction of vehicle detection area. A signal control scheme determines the transition among signal phases and the time that a phase lasts for. However, the existing signal control scheme do not resolve the traffic congestion effectively since they use restricted traffic information. In this paper, a new traffic detection system with a zone division signal control scheme is proposed to provide correct and detail traffic information and decrease the vehicle's waiting time at the intersection. The traffic detection system obtains traffic information in a way of vehicle-to-roadside communication between vehicles and sensor network. A new signal control scheme is built to exploit the sufficient traffic information provided by the proposed traffic detection system efficiently. Simulation results show that the proposed signal control scheme has 121 % and 56 % lower waiting time and delay time of vehicles at an intersection than other fuzzy signal control scheme.

• Journal of IKEEE
• /
• v.23 no.4
• /
• pp.1381-1386
• /
• 2019

As traffic congestion in cities becomes more serious, intelligent traffic control is actively being researched. Reinforcement learning is the most actively used algorithm for traffic signal control, and recently Deep reinforcement learning has attracted attention of researchers. Extended versions of deep reinforcement learning have been emerged as deep reinforcement learning algorithm showed high performance in various fields. However, most of the existing traffic signal control were studied in a single intersection environment, and there is a limitation that the method at a single intersection does not consider the traffic conditions of the entire city. In this paper, we propose a cooperative traffic control at multi-intersection environment. The traffic signal control algorithm is based on a combination of extended versions of deep reinforcement learning and we considers traffic conditions of adjacent intersections. In the experiment, we compare the proposed algorithm with the existing deep reinforcement learning algorithm, and further demonstrate the high performance of our model with and without cooperative method.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.2 no.1 s.2
• /
• pp.41-52
• /
• 2003

The purpose of this study was to test the effects of the pedestrian green signal adjustment on clearance of the turning vehicles impeding the through traffic flow at the signalized intersections, and thereby, suggest some operational criteria for adjustment of the pedestrian green signal. In order to test such effects, the pedestrian green time was adjusted so that it could started a few seconds later than the vehicle green time during peak hours, and thereby, the turning vehicle volume not cleared at the intersection was measured by extending the time gap by 2 seconds. (In general, the pedestrian green signal turns on at the same time as the vehicle green signal.) The results of this test can be summed up as follows; first, the longer the time gap was, the turning vehicle volume not cleared from the intersection decreased more. Second, in case there existed a storage space between intersection and crosswalk the effect of the turning vehicles on the through traffic flows was minimal. Third, at the pelican, the effect of the turning vehicles on the through traffic flow was minimal due to the structure of the intersection and the phase sequence. In conclusion, it was found that the adjustment of pedestrian green signal had the effect of enhancing the intersection operation. When adjusting the pedestrian green signal, it was deemed necessary to thoroughly survey the geometric structure of the intersection and collect the data on the turning traffic volume and thereby, apply the results of analysis flexibly to each intersection.

• Journal of Korean Society of Transportation
• /
• v.24 no.4 s.90
• /
• pp.93-101
• /
• 2006

The signalized intersections near highway-railroad grade crossing are operated without signal preemption in Korea when trains are approaching the crossing. This signal operation is very dangerous because queues from the intersection can extend back over the track, thereby creating the Potential for a serious vehicle-train accident. And the queues from the crossing can extend to the intersection with the normal signal operation while trains Pass the crossing. In this case the intersection is disrupted, and delay and the Potential for vehicle accident increase highly In order to improve the intersection performance and Protect the accident the crossings and intersections. signal Preemption designed to provide a special control mode should be implemented. In this study it was shown that intersection Performance near highway-railroad grade crossing improved using signal preemption. When signal Preemption is implemented at the test site, the delay was reduced by about 9sec/veh. Even though there were vehicle-train accidents at the crossing in all 30 simulations without signal preemption. there was no vehicle-train accidents at all when signal preemption is used.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.6
• /
• pp.296-301
• /
• 2020

Three types of traffic signal systems are two-color signal systems that flash red and green and are mainly used on crosswalks, next, three-color equalization systems mainly used at T-shaped intersections with red and yellow lights and a green arrow, and third, four-color intersections that generally have red, yellow and green colored lights and a green arrow. In what is known as the "dilemma zone" area, a driver collects information that influences his/her decision whether to stop, speed, tail, interrupt, or violate a traffic light, depending on the intersection width, vehicle speed, cognitive response time and reference yellow signal time. This study examined the impact of changes in the length of the dilemma zone areas based on changes in yellow signal times, the speed of the intersection passages, and signal lamps. Downward adjustments of 50km/h and 60km/h affected yellow signal time. The yellow signal time increased by 0.1 to 2.3[s] due to this effect and the dilemma zone area increased by 1.22 to 26[m]. The driver of the dilemma zone could quickly decide to reduce the time remaining of the straight (3color, 4color) green signal to reduce the potential of a traffic accident at the intersection traffic. Safe entry of red (LED palm) and left-turn signals for entering flashed at the intersection and operated at midnight.

• International Journal of Highway Engineering
• /
• v.11 no.3
• /
• pp.61-74
• /
• 2009

Traffic accident risk index Computation model's development apply traffic level of significance about area of road user group, road and street network area, population group etc.. through numerical formula or model by countermeasure to reduce the occurrence rate of traffic accidents. Is real condition that is taking advantage of risk by tangent section through estimation model and by method to choose improvement way to intersection from outside the country, and is utilizing being applied in part business in domestic. However, question is brought in the accuracy being utilizing changing some to take external model in domestic real condition than individual development of model. Therefore, selection intersection estimation element through traffic accidents occurrence present condition, geometry structure, control way, traffic volume, turning traffic volume etc. in 96 intersections in this research, and select final variable through correlation analysis of abstracted estimation elements. Developed intersection design model taking advantage of signal type, numeric of lane, intersection type, analysis of variance techniques through ANOVA analysis of three variables of intersection form with selected variable lastly, in signal crossing through three class intersection, distinction variable choice risk in model, no-signal crossing risk distinction analysis model and so on develop.

• Proceedings of the IEEK Conference
• /
• summer
• /
• pp.365-370
• /
• 2004

In this paper, we wish to construct a optimal traffic cycle using wire remote control. if police vehicle or ambulance suddenly enter the traffic intersection, it will increase the traffic accident. In this paper, wireless traffic light use the radio traffic control signal and research about the hardware manufacture to check special detectors on urgency vehicles may safety and rapidly enter traffic intersection. Also, this paper present a traffic signal control conditions that analyzes different traffic intersection flows in cases of saturated flows, where the real traffic volume demand is large and the capacity constraints of bottlenecks have significant effects on the flow patterns. Through computer simulation this wireless traffic light has been proven to be much more safety and efficient than fixed traffic signal light which does not considering emergency vehicles for safety escort.

• Journal of Information Technology Services
• /
• v.16 no.4
• /
• pp.223-234
• /
• 2017

The audible pedestrian signal (APS) is an add-on device which connects to the pedestrian signaling device and informs the contents and changes of the signaling by sound. It provides walking direction information of the pedestrian crossing so that the blind people can safely cross the pedestrian crossing. In an intersection where a plurality of audible pedestrian signal (APS) are installed at an intersection crosswalk, existing audible pedestrian signal (APS) operate simultaneously in the communication radius of a wireless remote controller, which may cause confusion for the blind people and the public may complain about the noise. In this paper, we developed a BLE (Bluetooth Low Energy)-based audible pedestrian signal (APS) system capable of supporting two-way communications with a smart-phone that can cross the intersection safely and improve the walking comfort and traffic safety for the blind people. The proposed method is a method in which the BLE beacon communication based audible pedestrian signal (APS) presents active service to the blind people, and the existing audible pedestrian signal (APS) is a way of requesting the passive service by the blind people with the wireless remote control by the unidirectional communication based on 358Mhz. The developed system is installed in the crossroad of Doma-dong, Seo-gu, Daejeon, and it is tested and operated by the blind people. The satisfaction evaluation and analysis of the audible pedestrian signal (APS) for the blind people have good results and are planned to be expanded in the future.