Understanding the Mystery Behind Unexplained Traffic Jams

A phantom traffic jam, also known as 'jaminton' or 'ghost jam,' is a traffic jam that occurs without any apparent reason. The term was coined by mathematicians and engineers studying traffic flow theory. Phantom traffic jams are also called 'highway waves' because they appear wave-like when plotted on a graph. These sudden stop-and-go patterns emerge out of nowhere, frustrating drivers who can't see any reason for the delay. These strange occurrences were first identified in the 1930s, but their complex dynamics have puzzled researchers ever since. In the absence of accidents, construction work, or other apparent obstructions, it's unclear why they happen. The simplest explanation for phantom jams is that they arise from disturbances caused by small changes in vehicle speed. Suppose there's a temporary perturbation - someone swerves or brakes suddenly. At the same time, this disturbance would usually die away if the road's traffic volume is above a certain threshold; this doesn't happen. Instead, it amplifies into a backward-traveling wave, which means vehicles further back have to slow even more until it becomes a stop-and-go shockwave. Some research indicates these phantom jams can be resolved with adaptive cruise control systems in newer vehicles that could calm the human causes of these events. Lastly, maintaining uniform speeds and distances between cars could help prevent these ghostly gridlocks, leading to smoother and more efficient driving experiences for everyone on the highway [1]. Sources: [1] Nakayama A., Sugiyama Y., Hasebe K., Nishinari K (2019). 'Instability of Traffic Flow – A Review from Full Vehicle Automation Perspective.' Discrete Dynamics in Nature and Society. https://doi.org/10.1155/2019/8214608