IIT Bombay researchers develop framework to test decentralised traffic systems

Mumbai, Aug 28 (PTI) Researchers from Indian Institute of Technology (IIT) Bombay on Thursday said they have developed a computationally efficient mathematical framework based on network theory to test decentralised traffic control systems with the aim of improving urban traffic management and reducing congestion.

Dr Namrata Gupta and Professor Gopal R Patil from IIT Bombay, in collaboration with Prof Hai L Vu from Monash University, Australia, have introduced a new framework to evaluate certain traffic control systems.

Even resource-intensive simulations often fall short of capturing the full range of real-world traffic scenarios, said IIT Bombay researchers.

To address this limitation, researchers at IIT Bombay have developed a mathematical framework based on network theory that enables more efficient and comprehensive testing of decentralised traffic control systems.

This novel approach introduces two metrics to evaluate traffic control policies, where both metrics can be computed by simulating the policy on what are known as two-bin network systems.

The simulation requires much less computing power and time as the first metric measures how effectively a policy can avoid gridlock, where traffic in any direction comes to a halt. It indicates the ability of a policy to evenly spread vehicles across different directions and ensure smooth flow.

The second metric captures how quickly a policy can clear traffic jams.

"Our proposed metrics can be applied to any traffic control policy, including those based on machine learning, provided the policy can be adapted to the structure of the two-bin model," Prof Patil said.

A major advantage of this framework is its efficiency as network performance can be calculated based on just a few simple equations, without laboriously modelling every single car and intersection, said Dr Gupta.

"The two-bin model is a macroscopic abstraction, governed by two simple ordinary differential equations. We can obtain network optimal performance theoretically. Further, this model requires much less computation, enabling rapid evaluation of multiple traffic scenarios," she added.

Even though the method appears robust, it cannot simulate every possible traffic state, according to the research.

"While it is impossible to simulate all possible traffic states, we incorporate such theoretical results to design diverse scenarios that include variations in congestion levels, demand patterns, and network configurations, which are chosen to reflect diverse operating conditions," clarified Prof Patil.

Another limitation of the framework is that it cannot be applied effectively to complex road networks.

"Extending these bin-based models to capture pedestrians is not straightforward. Pedestrian movement is governed by different dynamics and constraints compared to vehicular flow," Dr Gupta added.

Looking forward, the researchers hope to link their new performance metrics to familiar quantities such as travel time and waiting time, making the findings even more practical. PTI SM BNM