Modernization Reduces Noise on D1 Highway: Traffic Seems Half as Loud, Say Officials

The recent modernization of the D1 highway between Prague and Brno has successfully reduced noise levels by 3 to 6 decibels, surpassing officials’ expectations. Previously, noise levels on the oldest Czech highway ranged from 101 to 104 decibels. After the reconstruction, the noise levels have dropped to approximately 98 decibels.

According to Radek Kropelnický from the Road and Motorway Directorate (ŘSD), the noise reduction represents a significant improvement of at least 3 dB or more. This decrease in noise is equivalent to halving the traffic intensity at specific locations while maintaining the same proportion of passenger and freight vehicles.

As part of the project, a noise map of the highway has been created to monitor the development and behavior of noise levels over time and across different road surfaces. Selected highway sections feature asphalt and concrete road surfaces, providing drivers with varied experiences.

The noise levels were measured using the CPX method, which directly measures noise at its source – in this case, the specialized trailer tires moving along the road. The measurements covered all sections of the highway that were put into operation between 2014 and 2022.

On the first map, sections with standard surfaces are highlighted in light green, while sections with specialized surfaces for reduced noise are depicted in a darker shade of green. The second map illustrates the current noise levels and shows the changes over time, up to an eight-year difference between certain sections. The highest noise levels are observed between the 75th and 66th kilometer, near the Hořice and Loket exits.

The successful reduction in noise levels on the D1 highway is a significant achievement of the modernization efforts. It improves the quality of life for nearby residents and enhances the overall driving experience for motorists. The findings from this project provide valuable insights for future road design and noise reduction initiatives.