Someone is causing Slovenian road congestion: experts have been ignoring facts for decades that the West has known for almost a century – Slovenian road congestion

It's a big ride for many 500 kilometers to Makarska, once a year, with the air conditioning at its maximum and nerves at its minimum. For some of us, a vacation is a journey of several thousand kilometers. This year, I 8,000 kilometers route through Austria, the Czech Republic, Poland, the Baltic states, Finland, Sweden, Norway, Denmark and Germany. Much of it on ordinary two-lane roads. Without five new viaducts and without a minister explaining to me on the radio that the congestion is a result of economic growth and the increase in vehicles. And yet almost no congestion. No sudden braking, panicked lane changes or an incident that brings half the country to a standstill ten minutes and five kilometers behind.

When you return home, you quickly see that our biggest traffic problem is not the road. He sits behind the wheel and in offices strongly connected to the road construction lobby. Geographically, we are in Central Europe, but traffic-wise, we are in Butale. Here, the driver in the left lane believes that 130 km/h is the minimum recommended speed, and the safety distance is the space that the state mistakenly left for another car to merge. A traffic expert supports him in this.

Due to a neurospecific syndrome, I don't just read the road with the steering wheel, but with my eyes. I read the floor lines, their lengths and spacing. I read the signs, where and how they're placed, when they slow you down and when they should, but don't. I look at the heights of the fences. I notice the intentionality that most drivers never notice. And every time the same illusion collapses: we think we have a problem with the density of cars. We don't. We have a problem with the density of something else. And you have neither the expertise nor the brains. 

Stagnation from nothing: physics that is unwanted in our country

You know that moment when you're stuck in traffic, slowly creeping forward, waiting for an accident or a construction site, and then there's nothing? No police, no wreckage, no reason. It's not bad luck. It's physics, and it even has a name.

Traffic engineers call this a phantom traffic jam. A team from MIT has shown that such a traffic jam spreads along the road in exactly the same way as a detonation wave after an explosion. The birth is always the same: someone in front gets a moment too close to the vehicle in front of them and slams on the brakes, the next one brakes harder, the third one even harder, and the thirty vehicles behind them stop. Meanwhile, the first three are already driving ahead and never know, that they had just set off an explosion. The Japanese proved the same thing in the laboratory in 2008: 22 vehicles on a circular track, 230 meters long, evenly at 30 km/h (19 mph), without a hitch. It ran smoothly for a few minutes, then a traffic jam formed on its own from minor differences. Estimates say that up to half of all traffic jams have no visible cause. They are caused by driving culture, not a lack of asphalt.

Physics is an unpleasant thing. It doesn't vote, it doesn't read Facebook comments, and it doesn't let itself be convinced by high beams.

Annoying math: why 130 gets you almost nothing

Now for the numbers that knock the Slovenian off his chair. A car at 130 km/h it has almost 40 percent more kinetic energy than at 110 km/h. At 130 km/h transport in one second 36 meters, and at 110 km/h, a good 30. That's almost six extra meters every second the driver is looking for his phone, setting up the navigation, or getting angry at the person in front of him who clearly didn't understand that Janez from Šentjernej was in a hurry.

More importantly: Traffic is not at its busiest when everyone is driving at their fastest speed, but when everyone drives as evenly as possible. Large differences in speed (in lanes), insufficient distance and sudden braking create a wave that travels back through the line. One brakes with 130 to 90 km/h, others on 70 km/h, The fiftieth one stands and listens on the radio that the increased traffic is to blame. That is why in developed countries they use the term speed coordination. Measurements show that standardization increases the throughput of the road by approximately 10 percent and almost halve the likelihood of traffic breaking up into a queue. German experience shows that the road carries the most vehicles somewhere around 80 km/h, not at 130.

We have proof at home. On the Styrian access road to the Ljubljana Ring Road, traffic jams occur as early as 3,700 vehicles per hour, because there are many trucks and the connections are too close together. On the Dolenjska access road through the tunnels, where the speed drops to 100 km/h, there is no congestion even with more than 4,300 vehicles per hour. There are even more examples. And before you start lamenting the lost time: on a half-hour drive, the difference between 100 and 120 km/h is about two minutes. Two.

System, not miracle: Netherlands 100, Norway 80

That's why countries with well-organized traffic have something that we lack. A system. The Netherlands is the general daily limit on motorways 100 km/h (62 mph), even on six-lane roads. In Norway, outside built-up areas, there is a general speed limit 80 km/h (50 mph). Not because their cars can't go faster, but because their decision-makers understand that the goal of the road isn't to achieve the highest speed between two braking points. The goal is to get to your destination safely and predictably. Simple, boring, efficient.

The Ljubljana Ring: How Half of Europe North of Us Does It

Anyone who has ever driven towards a large Scandinavian city knows what comes next. Oslo, Helsinki, Stockholm, Gothenburg, Copenhagen. All these rings start to slow down traffic well before the city. According to my measurements on the ground, somewhere 20 kilometers before the ring. The limit is gradually lowered, in Scandinavian countries often from 110 to 90 km/h (56 mph), and this limit applies regardless of the road order. It is not set according to how much the road can carry, but according to how many cars use it during peak hours.

The most beautiful proof is the Swedish Essingeleden. An eight-lane highway through Stockholm, the busiest road in Sweden with 150,000 to 170,000 vehicles per day, is limited to 70 km/h (43 mph). Not because it couldn't handle 110, but because it would collapse at 110 during rush hour. The same applies through Gothenburg. Helsinki's Kehä I ring road never exceeds 80 km/h due to density. Finnish city access roads run at 100 instead of 120 km/h. The Danes are lowering the speed limit on Copenhagen's Køge Bugt with dynamic signs. The Norwegians go the furthest: their highest motorway ceiling is 110 km/h, while city sections of bypasses are 80 or 70 km/h.

It is also fair to say that Macarolo's analysis is not propaganda. The Scandinavian ceiling is not a single magic number. Norway stops at 110, Sweden allows 120 in some places, Denmark even 130 km/h. So the point is not the number on the board. The point is the rule by which this number is generated: it follows the expected density, not the order of the road.

Now our ring. The Northern and Western Bypasses are expressways with a speed limit. 100 km/h, the southern highway is 130 km/h (81 mph). Western transport around 77,000 vehicles per day and has connections so dense that it almost acts like a city street on steroids. According to Scandinavian logic, the calming should start already in Vrhnika, Lukovica and Grosuplje, at about 100 km/h. The southern bypass would carry 90 during peak hours, while the northern one would be lowered to 70. Not because of noise and not because of fines. Because of fluidity. Our problem is conceptual: we copied the outdated German model, which ties the limit to the order of the road, but we didn't go and look at the Norwegian one, which ties it to risk and density.

Speed kills twice: once in a convoy, once in a ditch

Both stories, the columns and the fatalities, meet in the same variable. In speed. The energy of a collision increases with the square of the speed, and the probability of a fatal outcome increases even faster. So speed kills twice: once by turning a small mistake into a column, and twice by turning a small mistake into a ditch.

Now, let's be honest, because this post is not an election flyer. Slovenia is not the Balkans on the road, at least when it comes to deaths. With around 70 victims, 2024 was the safest year ever since we started keeping statistics. With around 32 deaths per million population, we were below the EU average of 44, and among the eight safest countries in the Union. The real Balkans look different: Croatia 62, Bulgaria 74, Romania 77.

And yet. Behind every impressive number, there's another one that raises an eyebrow. In the same year, Norway recorded 16 deaths per million, Sweden 20, Denmark 24. So almost twice as many people die on our roads as on Norwegian ones. Twice. According to the first data for 2025, Slovenia has slipped to around 44 deaths per million, which is about 37 percent more than the year before and just above the EU average, while Norway remained among the safest in the world with about 19. The entire favorable trend collapsed in our country in one year. Silently, the number of seriously injured people is growing. Fewer dead, more maimed. Each fatality costs society an estimated 1.5 million euros. Not because of statistics, but because of an empty chair at the table.

Norway's success is not the magic of moose

The Norwegian result is not made by Nordic magic, moose, or the price of oil. An analysis of the period between 2000 and 2019 showed that 68.6 percent a drop in the number of deaths. Among the explanations were safer cars, better roads, sectional speed limits, median strips and physical barriers. And now the point that we in Butale find hard to swallow: the biggest individual contribution was made by the reduction in average speed. So exactly what the average driver understands as a personal attack on his constitutional right to rush to work at 150 km/h.

In the north, the median strip is not a decoration. It is a rough-hewn surface that jolts the driver awake in an instant when he is carried over it by fatigue. On a dangerous stretch of ordinary regional road, there is not a bouquet of flowers by a tree, but a median fence separating the lanes. The system anticipates human error and tries to prevent it from ending in a funeral.

Why I advocate 110, even though our roads are not bad

Here I will break down a favorite objection. Slovenian roads are not bad. In many places they are among the best in Europe. But they have a characteristic that the Netherlands or the Baltic states do not have: they are not straight. Our motorways wind through hills, over viaducts and through tunnels, where lanes narrow and traffic is jammed. That is why a unified, slightly lower speed suits them better than a flat 130 km/h. Not because the asphalt is bad, but because the terrain is demanding.

That's why I've long advocated for a trial restriction 110 km/h (68 mph) on the busiest and most structurally demanding sections of motorways. On the Ljubljana ring road, there should be restrictions during peak hours 70 km/h, before critical exits, junctions and motorway narrowings 90 km/h. Not just the scoreboard, but sectional measurement, dynamic limits and actual penalties.

I am not advocating slowness. I am advocating a higher average travel speed. Between a person who drives at a steady 110 km/h and a hero who accelerates to 150 km/h ten times, brakes to 70 km/h ten times and then stands in front of Lukovica for twenty minutes, the former often arrives at the destination earlier. The latter at least has the better feeling that he drove very fast for a while. Similar to a hamster in a wheel. I will not claim that this would eliminate exactly 70 percent of traffic jams, because numbers are not pulled out of a hat, although this is a popular methodology for election promises in our country. But it would certainly reduce speed differences, sudden braking, collisions, secondary accidents and the resulting traffic jams. This is not ideology. This is traffic mechanics.

We read and place road signs incorrectly

Here is another silent disaster. We don't play with driving psychology at all here. We place signs and markings according to the rules, not according to how the human brain reads speed. Engineers from Scandinavia to Japan have been using tricks for decades that force the driver to take his foot off the gas. Narrower and denser floor lines, patterns, colors that lie to the brain about speed. Cheap, quiet, no penalties.

I often hear the objection that the driver gets used to the illusion. He doesn't. I know a man who works in the Museum of Illusions, but after years of illusions, he still hasn't gotten used to it. The key is to use these techniques dynamically. You change the type of dashing and the way the fences are marked depending on the risk of the section. If 300 kilometers of road are marked exactly the same, the brain falls asleep, and the road becomes a monotonous straight line that invites you to accelerate. At the same time, we have the opposite problem elsewhere. A sign loses its meaning every hundred meters because the brain stops reading the forest of signs. In the north, speed is not controlled by multiple signs, but by geometry, surface and color.

The most painful lesson is the construction site. Let's take a section Kranj-Naklo. On a narrow lane, the speed limit is lowered to 60, then raised to 80 km/h, and that's in four kilometers. Each such change is a new opportunity for a wave, because someone brakes when they see 60. Why isn't it simply slowed down and reduced to 60 km/h, as the Scandinavians do according to the laws of physics. Slowing down should start two kilometers before the work site, not 500 meters. The driver needs time and space to remove his foot softly, not to brake in panic.

Third lane or bypass? Graz answered decades ago

It remains an important domestic issue. Do we need a third lane? In some places, definitely. But the third lane has a nasty characteristic: it fills up almost as quickly as you build it. A third lane without a change in driving culture is just a wider stage for the same show.

That's why I'm also betting on bypass connections that will remove transit from the ring road, and on a serious study of tunnels modeled after solutions like those known in Graz. The Plabutsch tunnel there, almost ten kilometers long double-tube tunnel on the A9 motorway, has been guiding traffic around the city for more than thirty years, relieving it of traffic congestion during peak hours. 50,000 vehicles per day from city streets. The most expensive kilometer is not necessarily the one underground. The most expensive is the one where 10,000 people stand every day.

An open invitation to Minister Vrtovec: 10,000 kilometers without PowerPoint

The new Minister of Infrastructure and Energy, Jernej Vrtovec, has openly made congestion one of the central issues of his mandate and has announced, among other things, the expansion of the motorway network and the implementation of night-time works on roads where work during the day disrupts traffic. He is right about night-time works and I congratulate him, because this is exactly the psychology I am talking about. But let's go a step further.

Minister, the offer is valid. We are transporting by electric car. 10,000 kilometers across northern Europe and documenting the journey on video. Without a protocol and without a PowerPoint presentation. We will measure average speed, consumption, sudden braking, traffic jams, restrictions and road solutions. Let's look together at why the centre line in Norway is roughly cut and not just painted, why the Dutch have set a speed limit of 100 and not 130 km/h on six-lane roads, and why there is a fence on a dangerous regional road, while here we have a cross and candles in the same place. Then we sit down at the table and look at the data instead of political feelings. Maybe in the end I will find out that I am wrong. Maybe the minister will be wrong. The physicist will not care at all.

The profession knows all this, the question is why does it ignore these things?!

And here I come to my conspiracy theory, which I can't prove, but I also can't believe it wouldn't. It is impossible for the profession not to know all these facts. The physics of traffic flow, speed coordination, the psychology of signs, dynamic limits: all of this has been known, measured and internationally recognized in the West for decades, some facts for almost a century. This is evidenced by both my simulators and the studies on which they are based. The people who regulate this in our country are educated and informed. So it's not about ignorance. Therefore, my personal opinion is that these unwaveringly recognized facts and standards are simply not taken into account because the profession itself is strongly connected to the road construction lobby. And a lobby that thrives on construction, expansions, and renovations simply cannot be satisfied with a cheap solution with paint and a smart board. I emphasize, this is a theory and my opinion, not a proven claim. But the longer I look, the harder it is for me to believe in coincidence.

Reformator broadcast: traffic as the first topic, and your vote counts

All these notes and experiments are part of the preparations for the first Reformator broadcast. Each month we will tackle one important topic for the country, and the first one on the program in September is transport. Not by chance. Transport is one of the key foundations of economic development and at the same time what hurts us the most every day.

Because I don't like to be taken at my word, I've compiled tools from international studies that you can try out for yourself. They're completely physical and run on research numbers. S road marking simulator you adjust the markings yourself and play with the perception of speed. With traffic jam simulator you see how the column forms without any obstruction. With simulators of the impact of autonomous driving but take a peek at what happens when cars start working together. I'll add a few more soon. All in the context of preparing for the show, which is coming in the first week of September. The main thing is a public debate on traffic policy. How traffic is a foundation that we should master and why this also affects real estate prices in Ljubljana and urban centers.

Every comment under every post will be recorded and analyzed using artificial intelligence. Included in the ideas presented in the show.  This way, together we will get both the public's and the professional's voice, not just the louder ones. Share, vote, comment. The more of us, the stronger the evidence.

A few words about simulations, because this is not improvisation. I have been working on app development and user experience and app development for decades, and in these I have prepared two simulations, and a third is on the way, so that you can understand it all more easily and test the consequences of increased speed yourself. Everything is open source. This means that in the name of science you can use this code, modify it and create your own. Each project is documented, with an explanation of the principles by which it works and what studies it is based on. That is why I ask you for two things: confirm the numbers and, if you have the appropriate knowledge, add your analysis. Science is not persuasion. It is verification.

You see, the problem was never the density of cars. The problem was the density of something else. And, unfortunately, a wider road doesn't fix that. A smarter head does.