Third Lane on A1 Won't Save Us: Professor Reveals the Real Causes
Traffic expert Marko Ševrović warns that widening the highway alone won't eliminate kilometer-long queues. Key culprits are trucks, the Drežnik viaduct, and a lack of alternatives.
Traffic expert Marko Ševrović warns that widening the highway alone won't eliminate kilometer-long queues. Key culprits are trucks, the Drežnik viaduct, and a lack of alternatives.
This morning's traffic situation on the A1 highway towards Karlovac once again confirmed the summer nightmare for Croatian drivers. Following a traffic accident, the vehicle queue stretched to a full 25 kilometers, with traffic already extremely heavy from 4 a.m. Although Croatian Motorways (HAC) is preparing a major reconstruction and the construction of a third lane on this section, Marko Ševrović, an associate professor at the Faculty of Transport and Traffic Sciences in Zagreb, believes this is not the ultimate solution to the problem.
Professor Ševrović explains to Index.hr that congestion is no longer limited to weekends. "Building a third lane won't solve the problems. We've reached a point where even Monday is overloaded," he points out. He sees the main reason in the specific regime for freight traffic in neighboring countries, which prohibit vehicles over 7.5 tons from using highways on weekends. "That's why they hit the road on Monday," Ševrović clarifies.
An additional problem is caused by tourists who misjudge the situation. "Tourists think there will be less congestion after the weekend, so they also set off on Monday and end up in that jam," the expert adds. Thus, at the start of the week, the same section sees both trucks that were waiting out the ban and citizens trying to avoid the weekend collapse.
Although a third lane would increase flow, Ševrović warns of key points that will remain problematic. "The bottleneck will occur at the Drežnik viaduct, which has only two lanes and no hard shoulder," he emphasizes. Increased capacity between Zagreb and Karlovac would only mean vehicles reach the point where the highway narrows again faster, shifting the queue further south, towards the Bosiljevo interchange.
He sees short-term improvements in widening acceleration and deceleration lanes at rest areas and building new interchanges, but stresses that this is not enough. The problem must be viewed along the entire route, not just the most critical section.
As a long-term solution to relieve the A1, the professor proposes building parallel routes. One of these is a highway on the Popovača, Sisak, Bosiljevo route. "This would provide a parallel to the A1, onto which part of the traffic could be diverted in the event of an accident or other disruption," Ševrović explains. This route would be particularly useful for absorbing traffic coming from Slavonia via the A3.
He places even greater importance on connecting Rijeka and Ljubljana via the Rupa, Ilirska Bistrica, Postojna highway. "This highway would greatly help Croatia. Traffic from the entire northern Adriatic would use it, drastically relieving congestion," he claims. He also calls for greater state engagement: "Croatia needs to put more pressure on the European Commission to give this project higher priority."
Ševrović believes that traffic accidents, often caused by inappropriate speed, are one of the main generators of queues. He criticizes the local mentality, noting that drivers consider 140 kilometers per hour slow. He sees the solution in introducing section speed control and monitoring vehicle spacing.
"This would reduce the number of accidents and increase traffic flow. The third lane on the A1 won't work without section speed control. It's essential," he states firmly. Such a system, modeled on some European countries, would also allow dynamic adjustment of speed limits to road conditions.
Although Croatia is introducing an electronic toll collection system that will eliminate stops at toll booths, Ševrović warns it won't remove the main causes of congestion. "The Lučko and Demerje toll plazas aren't the biggest problem. These two toll plazas already have greater throughput capacity than the highway itself," he explains.
The real value of the new system, he believes, lies in the possibility of building more interchanges, which was previously limited due to toll booths. "When disruptions occur, you have alternatives and don't have to wait ten kilometers in a queue," he concludes. Nevertheless, during the multi-year expansion works on the A1, he doesn't expect complete traffic chaos, recalling the successful reconstruction of the roundabout in Zagreb where "during the works, the situation was even better than before."
