- Published on 19 April 2022
A new approach to simulating traffic considers how drivers will change lanes at different rates depending on the density of traffic surrounding them
Many urban areas worldwide are now rapidly expanding, often with major negative impacts on traffic congestion. To address this issue, researchers have constructed models aiming to simulate the flow of traffic – but so far, they haven’t widely considered the impacts of drivers changing lanes. In a new study published in EPJ B, Nikita Madaan and Sapna Sharma at the Thapar Institute of Engineering and Technology, India, show how the lane-changing behaviours observed in real drivers can be incorporated into simulations of two-lane roads.
The duo’s results could provide valuable guidance for urban planners as they aim to minimise traffic congestion within fast-expanding cities. In the past, the models used to study flows of traffic could be divided into two broad categories: while ‘discrete’ models treated each vehicle individually, ‘continuous’ approaches didn’t distinguish between vehicles, and instead considered their average density. In this second case, traffic flow is comparable to the motion of a fluid.
More recently, a hybrid between these approaches has emerged, which models traffic a flowing lattice of discrete vehicles. These models are notably easy to simulate and analyse, and today, they have been extended to consider factors including weather conditions, accidents, and road quality. But so far, models of two-lane traffic have generally assumed that drivers change lanes at a constant rate: a behaviour which isn’t observed in real traffic.
For the first time, Madaan and Sharma have applied the lattice model to simulating more accurate lane-changing behaviours on a two-lane road. Their approach acknowledges that drivers tend to change lanes more frequently as traffic density increases; while above a certain density, this rate begins to decrease. It also shows that when drivers are more timid than aggressive, travelling waves in traffic density will tend to increase in length, and exhibit higher variations in density – decreasing the stability of traffic flow. In their future research, the duo hopes to incorporate more lanes into their simulations, and even consider the behaviours of self-driving vehicles.
Madaan, N., Sharma, S. Influence of driver’s behavior with empirical lane changing on the traffic dynamics, Eur. Phys. J. B 95:6, https://doi.org/10.1140/epjb/s10051-021-00270-0