The guidelines for the standardization of the superstructure of traffic areas, 2012 edition (RStO 12), were originally introduced in 2012 and published in General Circular Road Construction (ARS) No. 30/2012. Subsequent corrections and additions were made by ARS No. 27/2020. Based on accumulated experience and new findings, these guidelines were revised and published as the 2024 edition (RStO 12/24).

Innovations in RStO 12/24

The main changes include information on taking sustainable practices into consideration when dimensioning road pavements and adjustments to load classes and traffic types. In addition, the importance of the lane width factor is emphasized and the minimum deformation modulus of the unbound base or frost protection layer for the construction of cycle paths and footpaths is raised. In addition, there are further changes and editorial adjustments. The circular cancels previous editions and concludes with the recommendation to send the introductory decree to the Federal Ministry of Digital and Transport. The updated guidelines are available from FGSV Verlag GmbH.

Execution of paving work using the unbound construction method.

The RStO in brief

The guidelines for the standardization of the superstructure of traffic areas (RStO) are a recognized set of technical regulations that apply in Germany and are published by the Road and Transportation Research Association. It regulates the standard cases for new construction and renewal of traffic areas inside and outside built-up areas for the standardized superstructure. However, the RStO does not regulate rural roads, air traffic areas or traffic areas subject to special loads, for which separate technical regulations apply. When applying the standardized construction methods in accordance with the RStO, the assumed service life must be taken into account as a fundamental aspect in the sustainability assessment.

Unbound construction method in road building.