Emir Smailović, Faculty of Traffic: From urban planning errors to traffic jams and accidents - how did Belgrade's traffic collapse come about?

In such a context, questions arise that go beyond individual driver behavior - from the role of social norms and risk perception, through infrastructure quality and planning solutions, to how speeds, traffic hierarchy and system control are defined. About why Belgrade is lagging behind European practices and where the key systemic problems are located, Dr. Emir Smailović, professor of the Faculty of Traffic in Belgrade, speaks.

- Another example of successful traffic safety management is the city of Helsinki, which has not had a person die in a traffic accident during the calendar year since the summer of 2025. In the question itself, you already indirectly pointed out that the improvement of one traffic safety factor, such as the road factor, is not enough for the complete improvement of the system. The traffic safety system is made up of human-vehicle-road-environment factors. The interconnectedness and complexity of the relationship between these factors create the final result - whether and how many victims will be trafficked in the city. Each of these factors is individually important and contains dozens of features that significantly affect traffic safety. The public often discusses the question of why the same driver sometimes parks illegally in Vračar, while he never does the same in other countries? In addition to other contributions, the answer to such a question can be found in social norms that have a significant influence on traffic behavior. Traffic participants tend to behave in accordance with the environment, i.e. other drivers, therefore they change their behavior very quickly and adapt to the majority. So, for safe participation in traffic, education is needed, knowledge and compliance with regulations, skills, social attitudes are important, but social norms and risk perception have a dominant influence. What percentage of the society condemns some dangerous traffic behavior? What percentage of young people condemns risky traffic behavior? These are precisely some of the measures of social norms that I am talking about... Then, what is the certainty that this improper behavior will be sanctioned in a timely and adequate manner, when we are talking about the perception of risk. In addition to other differences in the quality of the infrastructure, the state of the vehicle fleet, the key differences between Belgrade on the one hand and Helsinki or Vienna on the other are just the facts mentioned.

Belgrade, like the national level of the Republic of Serbia, had a very successful period of improving the traffic safety situation after the adoption of the Law on Road Traffic Safety in 2009. And that period lasted until 2017-2018, after which we can talk about stagnation and a very slight decline in the volume of the problem. The reasons can be found in every entity, but the key ones are insufficiently good management, reduction of financial resources for improving the state of traffic safety, and inadequate coordination of the activities of various entities. The capacities of the institutions for implementing measures and improving traffic safety are declining, which has significantly contributed to the stagnation of the scope of the problem.

- Traffic accidents tend to migrate. Most of the traffic safety challenges in the central parts of the city when it comes to infrastructure have been solved, but new and more extensive problems have appeared in new locations. In the scientific literature, traffic safety is a very current topic of social inequalities, which are the result of different levels of safety. Suburban settlements are just mentioned as an example of that. Traffic accidents show marked spatial inequality, with rural/suburban areas bearing a disproportionate ratio. The proof of this is the fact that ten years ago the state road number 319 of the second B row through Dobanovce and Ugrinovce did not represent a significant traffic safety problem. Today, it is one of the most risky roads in the territory of Belgrade. The road must be adapted to its function, traffic volume, participants and environment. The key problem that occurs during the so-called "transitions" of state roads into local streets. This is the period during which the function of the road is reduced, the structure of the flow changes, so that the road is no longer dominated by long-distance trips, but by local service and going to the store. Many lives are lost until such a road receives its new function and is adapted to new driving conditions in the settlement. Every local self-government has similar problems in this regard. A separate question is whether the planning was adequate and why we allowed the mixing of diametrically different functions on the same road. It is certain that during the planning of the development of the road network and the granting of permits for the construction of new buildings, we (decision makers) made numerous mistakes...

It is true that most of these roads, above all in the part of the cross section, are not adapted to the environmental conditions. In practice, this means that the driver has the perception that he can move at a speed of 80 km/h in the settlement, because the road profile was identical to him before the settlement, where that was the permitted speed. Because of such road characteristics, drivers often do not have a good perception of what speed they should be moving, the speed for outside the settlement or the speed in the settlement.

The mentioned suburban roads have a large traffic flow, which is obstructed by numerous facilities and connections along these roads. Spontaneously, linear settlements appeared along state roads, which create huge problems in traffic safety and are not managed.

- In a project from 2016, the Faculty of Traffic proposed to the Secretariat for Traffic of the City of Belgrade to increase the speed limit to 70 km/h in Vojvode Mišića Boulevard and Radnička Street. Even some objects of uneven pedestrian movement were built on that stretch towards Obrenovac, which seemed to be going in that direction. Today, in the year 2026, we witness that the limit is still 50 km/h on that road, with occasional speeding measurements at the borders of the settlements on that road. This is precisely one example of social inequality, because certain social groups are more often exposed to traffic enforcement measures that are, to say the least, debatable.

Bulevar Heroja from Košar is another example of a road that was designed and built for the most part for safe movement at speeds above 50 km/h. On most of this street, today`s conditions allow safe movement at speeds higher than 50 km/h, but the speed limit is 50 km/h. An automatic speed detection system has even been installed.

I`m not sure that the problem only in the design of the northern tangent led to today`s paradox that we have a cross-section of an expensive and multi-lane road where the speed is limited to 50 km/h. Much bigger problems arose during the construction and the changes that occurred during the project implementation.

- Technical means for slowing down traffic. We even have a rulebook for it! (Regulation on technical means to slow down traffic on the road.)

From an engineering point of view, a technical means to slow down traffic is the last measure to be used, when other measures have been exhausted and there is no other way to regulate traffic. Previous measures are education, training, construction of roads that indicate the speed to the driver with their profile, cameras for automatic detection, etc. A particularly significant measure is the construction of roads that show the driver the speed limit on that road with all profiles. For example, we in Belgrade, as well as in the rest of Serbia, very rarely use zones 30, which are very efficient in speed control. Even when we use them, we just place the traffic sign zone 30, while the road curtain remains asphalt 6 m wide, which is the case in Strahinjića Bana street. This street does not differ in its profile from Cara Dušana street, where 50 km/h is allowed. And actually the idea of ​​zone 30 is to have a special road curtain and arrangement such that a speed of 30 km/h is acceptable for every driver.

Of course, there are other technical means to slow down traffic, such as vibrating belts, rustling belts, plateaus, narrowing of the roadway, etc. An effective measure that is not used enough is narrowing the roadway.

First of all, it is necessary to develop adequate plans in the short term, which would define the dynamics of the realization of the key infrastructure challenges. Solving these challenges is not simple, nor can it be realized in the short term. But it is important to work on it every budget year, as well as every calendar year.

- The urban network of Belgrade, as well as other cities, is very far from the necessary requirements of autonomous vehicles. Newly built parts of expressways in some parts can meet the demands of autonomous vehicles. A wide set of measures is needed, from design, through quality and traffic signal equipment, to maintenance. Currently, the biggest challenges are in the area of ​​maintenance, which cannot respond to much smaller demands than those of autonomous vehicles.

- In the coming period we can expect a further increase in the level of motorization. Currently, Belgrade has about 440 passenger cars per 1,000 inhabitants. According to the experience of others who have gone through similar phases, we can expect a continuation of the rapid increase in the degree of motorization above 500 vehicles per 1,000 inhabitants. Which certainly means more crowds. The key requirement would be to develop a strategy and work towards implementing it. Not that we allow the system to spontaneously develop without our management. Therefore, in that part, the development of the capacity of the institutions that should implement strategies and action plans is key. The certainty of the implementation of strategies will depend on the capacity of institutions.

The most important strategies are, of course, shortening the travel time by public transport (which can be achieved by building the subway); multimodal transportation and land use planning; more secure infrastructure adapted to all users; safer behavior of participants; effective response to accidents by strengthening one`s own capacities; development of pedestrian and cycling traffic (scooters); consistent application of regulations; construction of key missing infrastructure (eastern part of the ring road); the development of urban corridors with higher speeds; application of zone 30 on all city streets with one lane per direction, etc.