The recent modernization of the D1 highway between Prague and Brno in the Czech Republic has successfully achieved a significant reduction in noise levels, surpassing officials’ expectations. Before the modernization, the 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), this noise reduction represents a substantial improvement of at least 3 decibels or more. A decrease of 3 to 6 decibels is equivalent to halving the traffic intensity at specific locations while maintaining the same proportion of passenger and freight vehicles.

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

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

The first map highlights sections with standard road surfaces in light green, while sections with specialized surfaces designed 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, reflecting up to an eight-year difference between certain sections. The highest noise levels are observed between the 75th and 66th kilometers, near the Hořice and Loket exits.

The successful reduction in noise levels on the D1 highway is a significant achievement for the modernization efforts. It not only improves the quality of life for nearby residents but also enhances the overall driving experience for motorists. The findings from this project provide valuable insights for future road design and noise reduction initiatives, contributing to a more sustainable and comfortable transportation infrastructure.

Article by Prague Forum