Effects of countdown timers on queue discharge characteristics of through movement at a signalized intersection

Limanond, Thirayoot; Chookerd, Suebpong; Roubtonglang, Natcha

doi:10.1016/j.trc.2009.05.005

Cited by 43 publications

(18 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Additionally, it would also decrease the lost time in the change of phases and perhaps increase capacity. However, some studies indicate that the start-up lost time can have some reduction (17-32%) although the saturation headway improvements are trifling (Limanond et al 2009). Nevertheless, the effect on safety of this SCD is still dubious, because the data in literature are controversial.…”

Section: Introductionmentioning

confidence: 99%

Comparison between common traffic lights and three types of traffic lights with visual cycle – a safety and capacity analysis

et al. 2015

View full text Add to dashboard Cite

Article Info AbstractKeywords: before-after study traffic lights countdown time devices traffic safetyThe objective of this paper is compare the common traffic lights (CTL) to three different types of traffic lights with countdown displays (SCD) and assess their effects on road safety and capacity. This comparison is required because the results found in the literature are divergent among countries and cities, and one of the SCD analyzed in our study is different from the SCD used worldwide. An observational before-after study was conducted to evaluate the safety and capacity in a period of one year before and one year after the implementation of the SCD in three Brazilian cities. The results indicate that the SCD models 1 and 3 had around 35%±14% reduction in the total number of accidents; the model 2, does not have significant reduction. In order to perform the capacity analysis a framework for data collection and an adaptation for estimation of initial lost time in each phase were developed. Considering the capacity analysis there was a reduction around 11% in the lost time in SCD model 1, 7% in SCD model 2 and 3% in SCD model 3. However the implications of this on capacity are trifle due to a small increase in the average headways for all SCD models compare to CTL.

show abstract

Section: Introductionmentioning

confidence: 99%

Comparison between common traffic lights and three types of traffic lights with visual cycle – a safety and capacity analysis

et al. 2015

View full text Add to dashboard Cite

show abstract

“…By definition, it is obvious that the saturation flow rate is independent of s d , so we emphasize that our surprising finding is that even the start-up lost time is invariant with s d due to the effect of latent heat. Previous reports have characterized how the start-up lost time can be affected by inclement weather [48], countdown timers [49,50], the time of day or speed limit [51], and distracted drivers [52,53]. However, to our knowledge there are no reports where the effects of the initial (static) car spacing on the start-up lost time were investigated, which is the novelty of our present work.…”

Section: Car Motion Through a Traffic Light 21 Smart Road Experimentsmentioning

confidence: 95%

Latent heat of traffic moving from rest

et al. 2017

View full text Add to dashboard Cite

Contrary to traditional thinking and driver intuition, here we show that there is no benefit to ground vehicles increasing their packing density at stoppages. By systematically controlling the packing density of vehicles queued at a traffic light on a Smart Road, drone footage revealed that the benefit of an initial increase in displacement for close-packed vehicles is completely offset by the lag time inherent to changing back into a 'liquid phase' when flow resumes. This lag is analogous to the thermodynamic concept of the latent heat of fusion, as the 'temperature' (kinetic energy) of the vehicles cannot increase until the traffic 'melts' into the liquid phase. These findings suggest that in situations where gridlock is not an issue, drivers should not decrease their spacing during stoppages in order to lessen the likelihood of collisions with no loss in flow efficiency. In contrast, motion capture experiments of a line of people walking from rest showed higher flow efficiency with increased packing densities, indicating that the importance of latent heat becomes trivial for slower moving systems.

show abstract

“…Concerning safety, the percentage of cycles where drivers violated the red light was measured slightly higher when timers were used; 30% against 24%. 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].…”

Section: Literature Reviewmentioning

confidence: 99%

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

Botzoris¹,

Papakatsikas²,

Profillidis³

et al. 2017

IJT

View full text Add to dashboard Cite

show abstract

Effects of countdown timers on queue discharge characteristics of through movement at a signalized intersection

Cited by 43 publications

References 8 publications

Comparison between common traffic lights and three types of traffic lights with visual cycle – a safety and capacity analysis

Comparison between common traffic lights and three types of traffic lights with visual cycle – a safety and capacity analysis

Latent heat of traffic moving from rest

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

Contact Info

Product

Resources

About