Exploring impacts of countdown timers on traffic operations and driver behavior at a signalized intersection in Bangkok

Selection and assessment of the relevant data for reducing the number of red-light running

“…Deviation for the seconds of RLR after red-light onset as well as taking 75th percentile it could be concluded that most of RLR occur in the first 3 seconds after red-light onset, compared to Limanond et al (2010) who showed the mean time of RLR was 4.13 seconds after onset of red phase. Countermeasures that could affect on the reduction of this problem are introduction of counters, extension of the protective time between red-light phases for opposite direction (for about 3 seconds), introduction of RLC etc.…”

“…Similar as Yan et al (2009), Awadallah (2009 suggested pavement marking with delineation of a yellow transverse line at the calculated decision line, where drivers should decide to stop or to move through the intersection. Limanond et al (2010) have researched impacts of countdown timers on traffic operations, but also driver behavior at a signalized intersection and found that timers decrease number of violation for 50% (mean time of RLR was decreased or about 25%, from 4.13 to 3.08 s) after the onset of the red phase. Ma et al (2010) have also examined effects of countdown devices on RLR and found significantly reducing in RLR.…”

“…(Elmitiny et al 2010;Wu et al 2012, Saunier, Sayed 2007, Ismail et al 2009, Limanond et al 2010. Tiwari et al (2007) also used a video camera but to examine pedestrian behaviour at signalized intersections.…”

Effects on Road Safety and Functionality of Installing Countdown Timers to Traffic Lights

“…Limanond et al, (2009) concluded that in Thailand countdown timers reduced the average vehicle start up delay by roughly one (1) second, which slightly increased the intersection capacity [5]. The next year, Limanond et al, (2010) found that the installation of timers in Bangkok decreased the start up delay time by 22%, there was no difference in drivers' behavior during the yellow signal and red light violations were reduced [6]. Sharma et al, (2009) analyzed queue discharge characteristics of two intersections, one with a timer and one without, in Chennai, India, through the use of a videotaping technique [7].…”

Analysis of car-following behaviors considering the green signal countdown device

“…Lum and Halim [1] estimated the difference in driver response along an approach of a signalized intersection installed with a green signal countdown device and found that it was practically effective in encouraging red-stopping actions under heavy traffic flows and that the longerterm performance of it would only help to encourage stopping but not curbing red violations. Limanond et al [2] explored the effects of the signal countdown timer at various stages of the signal cycle by using two approaches: a traffic analysis and a public opinion survey conducted in Bangkok and found that the presence of the green signal countdown device at the intersection can reduce the number of red-light violations during the beginning of the red phase by 50 %, help to relieve the frustration caused by stopping for uncertain amounts of time during the red phase, and slightly reduce the saturation flow rate during the green phase. Chiou and Chang [3] investigated the effects of the green signal countdown display and red signal countdown display on driver behaviors on intersection safety and efficiency and found that the number of vehicles ejecting to cross the intersection reduces following the provision of a green signal countdown device.…”