The results of a study carried out in the center of Turku in the early autumn shows that the Central Bridge, Tuomiokirkkosilta, is crossed by about 25,000 vehicles a day. One-fifth of the traffic on the bridge is traffic passing through the city center. About half of the vehicles that used the bridge were registered outside Turku.

 

The measurement period of the survey measuring and analyzing through traffic in the center of Turku took place at the turn of August-September 2021. License plate identification cameras were used to measure how much of the traffic is through traffic, where the traffic arrives and where it goes. With license plate identification, the vehicle type, propulsion power and emission class were also determined.

- The purpose of the study was to collect information on the through traffic of the Tuomiokirkkosilta to support planning and decision-making regarding traffic arrangements in the city center, says Juha Jokela, the City of Turku’s Development Manager.

During the measurement period, the traffic volume of the Tuomiokirkkosilta turned out to be about 25,000 vehicles per day. In the study, the definition of through traffic in the city center was met by about 20% of the bridge's total traffic. The highest number of through traffic came from Uudenmaantie and Tampereen valtatie. There was also a significant amount of traffic through the city center from Satakunnantie, Kuninkojantie and Littoistentie.

Average number of vehicles passing through per day from measuring points outside the middle ring (in gray) towards the Tuomiokirkkosilta (one way).

50% of the vehicles using the Tuomiokirkkosilta were registered outside the city of Turku and 27% outside the Turku region. The majority of the traffic at the measuring points, 90%, was passenger car traffic. When it comes to the share of vehicles passing through the Tuomiokirkkosilta, vehicles registered in Turku was lower, about 36%. The study also found that passenger cars are still predominantly petrol- and diesel-powered, but the propulsion of the latest passenger cars is shifting to hybrids.

- Similar kind of study has not been conducted in the city of Turku before. The chosen method served the purpose well and we obtained interesting results of the current state of the traffic in the center of Turku. In the future, the goal is to direct through traffic to the roads outside the city center, thus enabling better conditions for sustainable modes of transport and a more comfortable and safer city center, says Juha Jokela.

 

Research background

The City of Turku carried out a trough traffic study together with Nodeon in the city center of Turku 16.8.–7.9.2021. The research is part of the EU-funded HUPMOBILE project.

The study used three measurement setups with varying entry and exit points. In this way, it was ensured that the most comprehensive picture possible was obtained of the volume of through traffic and its share of the total traffic on the Tuomiokirkkosilta.

The trough traffic was defined occurring when the license plate was read at 1) the entry point, 2) the Tuomiokirkkosilta, and 3) the exit point within 15 minutes of the license plate being read at the entry point.