1. Effects of Countdown Traffic Signal On Driving
By : Elyas Jazayeri

2. Outline Introduction Previous Studies and Results Case Study Results
Conclusion and Future Recommendation
Technology

3. Introduction Pedestrian Traffic signal countdown
Good estimation for pedestrian
Comfortable
Policy
It should be implemented in united states with timer unless it is under 7 seconds

4. Introduction Purpose of Countdown Devices for Traffic signals
Improving capacity of signalized intersections by reducing lost time
Helping drivers better understand traffic flows
Enabling drivers to make decisions on the remaining time left on the green or red phase
Reducing the crash frequency of the intersection

5. Previous Studies First In 1970s, Texas and Florida , (Why abandoned?)
Singapore Experiment
China Case
Li dong and Yu
Limanond( Bangkok)
in Singapore case after 1.5 month, red lighting decreases and then came back to the previous level after 7.5 months
In china case, they investigate red and green countdown, they found green countdown extends the dilemma zone by 28 m which increased accident risk, but red countdown reduced early tart ups and after a while it came back to previous number,
Li dong and Yu, the green countdown signal increase number of accident in intersections and reduce safety for drivers. But they conclude that red countdown had good effect on traffic flow, drivers start earlier.
Limanond, in Bangkok , they concluded that start up lost time decreased from 8.32s to 6.53s. The result shows that it decreased 50% of crossing red light violation

6. Technical Issues Technical Issue 1 Technical Issue 2
Relying a lot on timer after a while
Most of the time driver get used to some technical issues but the new to the road drivers will get in trouble

7. Slovenian Case Study Based on three hypotheses
Based of vehicular countdown signals, the start up lost times at urban signalized intersection will decrease
Because of vehicular countdown signals, the number of amber light running violation at urban signalized intersections will be lower
Because of vehicular countdown signals, the number of red light running violation at urban signalized intersections will be lower

8. Slovenian Case Study Experiment: A-C , and C-A
The research was in 2007
They installed countdown timer and started their field research measurement
The experiment carried out in afternoon when cycle time was 100s
7 days period and first and last two days the counter was off
Both duration in red light and green llight

9. Slovenian Case Study Start up Lost time Video surveillance camera
Auto scope 2004
They mount surveillance out of sight of drivers
It records the traffic light as well as the queue of drivers
All videos will be processed in laboratory
It can say the amount of time when drivers pass the stop line automatically and also manually
We needed start and the end of red light phase, the amount of car that passes and the dilemma distance

10. Slovenian Case Study Policy Measurement
In Slovenia passing red is against the law, and passing amber light is against the law as well unless you cannot brake and you feel it is better to pas the intersection
Number of red light, amber light and amber and red light will be recorded for the calculation
Each measurement here will be calculated two times for accuracy and using enlarged video image, which is a feature of video player

11. Public Opinion Survey Short questionnaire survey 411 replies
Between the answers we can conclude that most of the drivers are satisfied with this system

12. Results
Rate of running violation before turn off was 14.5% and it increased immediately after turn off by 12%
Number of violation increased when the counter was off
84% of the respondents believe countdown is a good device
10% of respondents believe it is not good
6% of respondents believe it can be good and bad simultaneously
Overall the red time countdown has more positive influence than green one
The start up lost time doesn’t have differences between on and off

13. Future Recommendation
Percentage of congestion can be a parameter for the effectiveness of countdown timer
Effect of getting used to countdown traffic signal

14. Technology
EnLighten App

15. Question?