Jayasooriya

Nadika Keshan Jayasooriya, a gifted athlete, especially a skilled Badminton player, grew up in Colombo and witnessed the chaos on the roads of Sri Lanka and always felt that the situation should be improved. After his primary and secondary education at Royal College, Colombo, he entered the University of Moratuwa, and completed a Bachelor’s degree in Civil Engineering in 2014. He says, “I was keen to do something that could be practically applied, something that could better the conditions in Sri Lanka”. This was what motivated him to continue on to his PhD at the University of Moratuwa (UoM).

Nadika believes that one of the biggest problems on Sri Lankan roads and especially at intersections is the lack of effective traffic management. This leads to confusion, unnecessary delays and accidents. In urban areas, proper intersection control is very important, and proper traffic signal design and traffic signal coordination could improve the traffic flow. He says,“in particular, there is no uniformity in signal indications, signal head placement and phasing selection”. 

Nadika notes that different agencies have installed traffic signal lights in close proximity, with no proper coordination. "Signal coordination with similar type of intersections is well established in other parts of the world”, says Nadika, “but at non-similar intersections, there is a clear lack of guidelines”. So, Nadika, with his supervisor Prof. Saman Bandara undertook to develop suitable guidelines for traffic signal coordination of non-similar intersections.

Prof Saman Bandara is a senior professor in Civil Engineering at the University of Moratuwa. He has a Civil Engineering degree from UoM and is a PhD holder from the University of Calgary, Canada. He is an expert in Transportation and is acclaimed as a notable researcher in his discipline.

Both Nadika and Saman observed that at non-similar intersections, behavior of vehicular traffic is quite complex. This is because a direction of priority as well as variations in traffic during peak and off peak periods have to be determined. Due to such complexities, proper guidelines for traffic signal coordination at non-similar intersections is still missing.

Large amounts of data had to be analyzed to get to the heart of the problem. This was a project that needed simulation and big data analytics, and, “on the top of the list of things to do was to find a suitable simulation tool that could assist me with my project”, says Nadika.

The project benefited immensely from the generosity of the PTV group in Germany, who provided UoM with an educational license for VISSIM, a microscopic multi-modal traffic flow simulation software package. Nadika used this software together with third party vehicular traffic data to identify the possibilities of traffic signal coordination at intersections in Sri Lanka. He went on to develop guidelines for traffic signal coordination at individual intersections for both real time and fixed time systems as well as for non-similar intersections.

He was also able to develop a method to measure savings made on travel time and convert that into monetary terms that indicated the value of time that is saved. The estimated values of travel time savings were in the range of Rs.188 to Rs.528 per hour depending on the vehicle. He says that this method could be used in the evaluation of traffic management initiatives.

Nadika, together with his supervisor, has published their work in several local and international journals and presented at different forums. The paper presented at IESL Annual Sessions of the Institution of Engineers (IESL), Sri Lanka, in the year 2017 was awarded the "Eng. E. O. E. Pereira award" for the best paper.

Nadika is now an entrepreneur, and heads ACE Solutions, a company that provides transportation solutions. He is also working as a consultant in the Light Rail Project that is promising alternative transportation to road use. Further, He continues his research efforts and is currently working on a project to determine traffic signal timing adjustments using real time data. We hope Nadika’s work is well received by the transportation authorities and that he is able to continue his work as a solution provider for transportation in Sri Lanka.