• Journal of Korean Society of Transportation
• /
• v.29 no.6
• /
• pp.57-65
• /
• 2011

After heated discussion, National Police Agency decided not to install Red Arrow signal at such major intersections as Gwanghwamoon, Sejongro. The major issues can be summarized in the following reasons. The one is the conflict of color and symbol (red means STOP and arrow means PROGRESS), and it would confuse drivers and may cause traffic accident. The other includes high replacement cost. This paper delivered how much red arrow signal would affect (1) drivers start up delay time, (2) saturation flow rate and (3) vehicle headway. The result showed that there was no statistical difference in those even when a red arrow signal is placed.

• 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.