The Department of Roads and Transportation of the Faculty of Civil Engineering of the University of Sarajevo (UNSA) investigated how different types of intersections affect air quality in the capital of Bosnia and Herzegovina (BiH). Traffic signalized intersections and roundabouts were analyzed.
Ammar Saric, professor at the Department of Roads and Transportation of the Faculty of Civil Engineering, presented the results of a study called “The Influence of the Type of Intersection on air pollution”.
He explained that measures to reduce air pollution can be infrastructural and legal, such as the promotion of greater use of zero-emission vehicles and the ban on the use of certain fossil fuel vehicles. In the context of infrastructural measures, he highlighted the impact of intersections.
“Infrastructural changes, such as the reconstruction of intersections, can often solve the problem of traffic congestion and increase traffic safety. However, this can affect the increase or decrease of harmful gas emissions,” he said.
Research results
The research results showed that roundabouts at the three analyzed locations are not a good solution when it comes to air pollution.
“The results of the research can be viewed through two groups of intersections depending on the traffic load. The first group consists of two-lane roundabouts where the largest number of vehicles was recorded (eg on Dobrinja and Pofalici with more than 3.000 vehicles per hour). Compared to alternative solutions (traffic-lighted intersections and turbo rotors), these intersections cause more than 50 percent more emissions of harmful gases,” emphasized Saric.
Professor Saric further explained why certain roundabouts are problematic.
“Heavily traffic-heavy two-lane roundabouts cause the movement of vehicles in columns with a large number of stops and starts, which results in higher emissions of harmful gases. That is why their use is justified in conditions of continuous traffic flow with lower values of the degree of saturation (traffic)”, he pointed out.
The relationship between the type of intersection and the type of vehicle
The impact of replacing a certain number of vehicles with the lowest EURO standard with zero-emission vehicles and the impact of reducing the number of vehicles, i.e. the use of public transport, were also analyzed.
“The impact of 20 percent electric vehicles is the same for all intersections, and the reduction amounts to 20 percent of carbon dioxide (CO2) and fuel consumption, 29 percent of nitrogen dioxide (NOx), and 45 percent of particulate matter (PM). The impact of reducing the number of vehicles on reducing emissions is greatest at the roundabouts in Dobrinja, Buca Potok, and Pofalici, amounting to 40 percent, while at other intersections, it is 22 percent in the case of a 20 percent reduction in the total number of vehicles,” said Saric, Klix.ba reports.
E.Dz.
