There are no easy solutions, but could the introduction of larger freight spaces and combined vehicles on our roads alleviate both problems? In 2022, Marko Jürimaa defended his master’s thesis ‘Ways to utilize high-capacity transport in Estonia’ at Tallinn University of Technology (supervisor: Professor Dago Antov) to find answers to these questions.

So far, the link between roads and vehicles has been superficial

Jürimaa notes that the idea of researching this topic had been on his mind even before he started his master’s studies at TalTech.

‘For me, it was very tempting to link the road and the vehicle. Most of the time, different studies only look at one or the other, but the link between the two has remained somewhat superficial,’ he explains.

The more specific question Jürimaa was looking for an answer to in his research was the possibility of longer and heavier vehicles on Estonian roads. First, whether there is any demand for them, and second, if there is, what the infrastructure requirements – the carrying capacities and turning radii of the roads – are for such vehicles.

Jürimaa explains that, in the bigger picture, the shortage of lorry drivers is a major problem in Europe in general and therefore also in Estonia. In addition, to meet climate targets, CO2 production in the transport sector will need to be significantly reduced. The use of larger freight spaces could have a positive impact on both problems.

Surprising discoveries

Jürimaa, who works as a special transport coordinator in the Road Traffic Management Unit of the Transport Administration, says that he had some idea of what the results of the analysis might be, but there were some surprises.

The biggest ‘discovery’ was that the rotational geometry of the most commonly used combined vehicles with semi-trailers and the rotational geometry of the longer vehicles are very similar, and that in certain situations, the manoeuvrability of a combined vehicle with a semi-trailer is much worse than that of an EMS vehicle (EMS stands for European Modular System or a large-capacity combined vehicle).

It was also strange for Jürimaa that the EMS vehicle is described in the urban road standard, but not in the road design standards. ‘It seems as if it is possible to drive longer cars in cities, but not on the roads,’ he explains his surprise, adding that in reality, of course, standards and real life have little in common and that it is possible to drive longer combined vehicles on the roads.

The use of longer combined vehicles should be legalised

Jürimaa points out that the final result of the research was positive, i.e. longer combined vehicles could be used for road transport on Estonian roads. If the use of such vehicles were legalised, it would benefit everyone from transport companies to the final consumer of the goods transported.

Jürimaa explains that a reduction in the transport unit price could give a little back to all consumers. And the closer we get to our green targets with the help of different methods, the lower the future cost of fines for cars that emit more carbon dioxide than the norm, for example.

Jürimaa says that, of course, the use of longer vehicles in traffic makes the situation a bit more complicated. ‘For example, when overtaking, you have to take into account a slightly longer time than before, and on a cognitive level, such vehicles can be uncomfortable in traffic, but you cannot gain something without giving something in return,’ Jürimaa summarises.

The article was published on the Geenius portal in the blog ‘Teadus ja tulevik’ (‘Science and the Future’).