A traffic expert explains the causes of 'phantom traffic jams' (VIDEO)

Heavy rainstorms have dramatically altered traffic conditions across Slovenia, prompting warnings from road safety authorities about the dangers posed by sudden weather changes. On August 3, 2026, the Agency for Road Safety (AVP) issued urgent reminders to drivers about the risks associated with driving during severe thunderstorms, including reduced visibility, slippery roads, aquaplaning, and unpredictable wind gusts. These conditions can quickly transform otherwise safe roads into hazardous environments, particularly when drivers react impulsively to sudden downpours or hail. The AVP emphasized that one of the most common causes of dangerous situations is improper speed adjustment, insufficient following distance, and abrupt braking or lane changes. According to the agency, these behaviors significantly increase the risk of losing control of a vehicle. The agency warned that some drivers attempt to protect their cars by stopping on inappropriate stretches of road during heavy rain, which is extremely dangerous. Instead, they advised drivers to gradually reduce speed and find a legal parking area or rest zone if they feel unsafe continuing on the road. Aquaplaning, a phenomenon where vehicles lose traction due to water accumulation on the road surface, was highlighted as a particular concern. The AVP instructed drivers to remain calm if this occurs, keep the steering wheel steady in the direction of travel, ease off the accelerator, and avoid sudden braking or sharp turns. For manual transmission vehicles, pressing the clutch pedal could help regain control once tire contact with the road is restored. In addition to weather-related hazards, traffic experts have identified another issue contributing to unexpected delays on highways, so-called “phantom jams.” These occur when drivers maintain inadequate distances between vehicles, leading to unnecessary braking and lane changes. Erik Logar, head of Safe Mobility at the Auto-Moto Association of Slovenia, explained that phantom jams often happen near major cities where traffic density is high. He noted that frustration and impatience among drivers can exacerbate the problem, increasing the likelihood of accidents rather than resolving the congestion. Logar stressed the importance of maintaining a safety corridor within traffic jams, especially if the cause is unknown. This allows emergency services to reach the scene quickly if there has been an accident. He also cautioned against leaving vehicles during such situations, as it poses a serious risk to personal safety. Additionally, he recommended avoiding frequent lane changes, which can further complicate the situation. Intelligent transportation systems offer potential solutions to manage traffic flow more effectively. These systems use sensors to monitor traffic conditions and dynamically adjust speed limits in real time, helping prevent congestion before it starts. However, Logar pointed out that driver compliance remains a challenge, as many fail to understand why speed restrictions are imposed even when the road appears clear ahead. Traffic flow efficiency depends on multiple factors, including vehicle speed, traffic density, spacing between vehicles, and travel time. While higher speeds might seem beneficial, they require greater safety distances, potentially reducing the number of vehicles on the road simultaneously. Optimal traffic flow typically occurs at speeds between 70 and 100 kilometers per hour. If too many vehicles are present, speeds decrease, gaps shrink, and traffic can become stagnant. Conversely, very few vehicles result in fast-moving but low-volume traffic. Logar concluded that the number of vehicles on the road does not necessarily indicate inefficiency, as most drivers are traveling for essential reasons rather than leisure. He suggested optimizing passenger capacity in vehicles as a partial solution to reduce overall traffic volume. Improvements in infrastructure and the gradual introduction of autonomous vehicles could also contribute to smoother and safer traffic conditions in the future.