1. Chen, I.C., Chang, K.K., Chang, C.C., and Lai, C.H. The impact evaluation of vehicular signal countdown displays. Research Report. Institute of Transportation 2007, Ministry of Transportation and Communications, Taiwan.
2. Driver responses to green and red vehicular signal countdown displays: Safety and efficiency aspects;Chiou;Accident Analysis & Prevention,2010
3. Behavior and consciousness analyses on effect of traffic signals including countdown device for vehicles;Fujita;Journal of the Eastern Asia Society for Transportation Studies,2007
4. The effect of digital count-down display on signalized junction performance;Ibrahim;American Journal of Applied Sciences,2008
5. Krishna, K., C.V. Effect of countdown display on queue discharge characteristics at signal controlled intersections. M. Tech. Dissertation. [2014,] Indian Institute of Technology (IIT) Roorkee, Roorkee 247667, Uttarakhand, India.