Investigation of the discharge flow rate patterns at real-time traffic signal control intersections

Year 2023, Volume: 7 Issue: 1, 49 - 55, 15.01.2023

Nihat Can Karabulut , Murat Özen , Oruç Altıntaşı

https://doi.org/10.31127/tuje.1020765

Abstract

This study investigates the effects of variable queue lengths and green times on discharge flow rates at real-time managed intersections in Mersin, Turkey. For this purpose, traffic flow data were collected at two different signalized intersections during morning peak hours for two days. The traffic data including the time headways, queue lengths for each cycle were derived from video records via MATLAB coding while the signal timing data were obtained from Mersin Metropolitan Municipality. The impact of variable queue lengths and green times on discharge flow rate were evaluated separately via analysis of variance (ANOVA) tests. The results indicated that time headways of the first vehicles in the queue were statistically larger than the time headways of the remaining vehicles in the queue (p-value<0.05). On the other hand, the time headways of the remaining vehicles in the queue were not found statistically different at 95 confidence level (p-value>0.05). Furthermore, the effect of the variable green time on discharge flow rate revealed that the significant difference was only observed for the first twelve seconds of the green time. 

Keywords

Real-time managed intersection, Queue length, Green time, Time headway, Discharge flow rate

References

• Khosla, K., & Williams, J. C. (2006). Saturation flow at signalized intersections during longer green time. Transportation Research Record, 1978 (1), 61-67.
• Denney, Jr. R. W., Curtis, E. & Head, L. (2009). Long green times and cycles at congested traffic signals. Transportation Research Record, 2128 (1), 1-10.
• Lin, F. B. & Thomas, D. R. (2005). Headway compression during queue discharge at signalized intersections. Transportation Research Record, 1920 (1), 81-85.
• Stanić, B., Tubić, V. & Čelar. N. (2011). Straight lane saturation flow and its rate in Serbian cities. Transport, 26 (3), 329-334.
• Chaudhry, M. S. & Ranjitkar, P. (2013). Capacity and signal timing analysis of signalized intersections with increasing saturation flow rate. Transportation Research Board 92nd Annual Meeting (No. 13-3396).
• Dey, P. P., Nandal, S. & Kalyan, R. (2013). Queue discharge characteristics at signalised intersections under mixed traffic conditions. European Transport, 55(7), 1-12.
• Tanyel, S., Koyuncu, M. & Çaliskanelli, S. P. (2018). Sürücü davranışlarının sinyalize kavşak başarımı üzerindeki etkisi. Teknik Dergi, 29 (5), 8563-8588.
• Li, H. & Prevedouros, P. D. (2002). Detailed observations of saturation headways and start-up lost times. Transportation Research Record, 1802 (1), 44-53.
• Day, C. M., Sturdevant, J. R., Li, H., Stevens, A., Hainen, A. M., Remias, S. M. & Bullock, D. M. (2013). Revisiting the cycle length: Lost time question with critical lane analysis. Transportation Research Record, 2355(1), 1-9
• Gao, L. & Alam, B. (2014). Optimal discharge speed and queue discharge headway at signalized intersections. In 93rd Annual Meeting of Transportation Research Board, CD-ROM. Washington, DC, United States.
• Transportation Research Board (TRB) (2010). Highway capacity manual (5th Edition). Washington, D.C.: Transportation Research Board, National Research Council.
• Cohen, S. L. (2002). Application of car-following systems to queue discharge problem at signalized intersections. Transportation Research Record, 1802(1), 205-213.