Loud vehicles and quiet tires

Motorcycle
© Fraunhofer IBP
Motorcycle on the Fraunhofer IBP vehicle test stand.

The goal of the state government of Baden-Württemberg is to reduce noise pollution from road traffic to a tolerable level. Among other measures at state and federal level, particular attention is being paid to motorcycle noise and the potential of quiet tires.

As far as motorcycle noise is concerned, very little reliable data is currently available on noise emissions specific to vehicles and driving conditions. This hinders an objective public discussion and restricts the targeted legal measures which can be used to achieve a noticeable reduction in road traffic noise.

Due to stricter limits and rising e-mobility, external rolling noise from tires is increasingly becoming the focus of attention in the quest to further reduce noise levels. The external rolling noise rating is marked on tire labels, which are intended to enable consumers to identify quiet tires and make an informed decision when buying them. At present, however, it is not clear how comprehensible these labels are to the customer, or how much they influence their choice of tire.

Project goals

Loud motorcycles

Particularly in the case of motorcycles, noise emissions much depend on driving behavior. In practice, these can deviate significantly from standardized driving cycles for acoustic pass-by measurements relevant to approval. This is one of the reasons for conflicts among the parties concerned in discussions. The extent of these differences between standard cycles and the way motorcycles are driven on roads in practice is not sufficiently known, nor has it been investigated and documented in studies. Consequently, the data base needs to be extended on an impartial level. To this end, Fraunhofer IBP is using its vehicle test stand to conduct systematic acoustic tests on representative motorcycles.

The results of these investigations will create the necessary data basis for objective discussions as well as the foundations for targeted legal intervention to noticeably reduce noise emissions from motorcycles in road traffic.

Quiet tires

As noise emissions from vehicle powertrains steadily decrease and vehicle noise limits become even stricter, the pressure on tire manufacturers to produce quiet tires with reduced external rolling noise has risen constantly in recent years. As a result, more and more quiet tires are coming onto the market. The external noise rating is marked on tire labels, which are intended to enable consumers to recognize quiet tires and make an informed decision when buying them. However, consumers currently still seem to lack an overview of available products and the correlations between noise-reducing properties and the other tire parameters. Fraunhofer IBP is therefore compiling an up-to-date market overview of quiet tires and tire labels, as well as making the impact of key parameters on the acoustics of quiet tires understandable to the customer. Surveys will also be conducted to obtain an up-to-date picture of the acceptance and comprehensibility of tire labels among experts and the general public.

Concepts for stimulating communication and increasing awareness about noise protection when purchasing tires will be derived from the market assessment results and from the feedback from market participants.

Elke Zimmer, State Secretary of the Ministry of Transport Baden-Württemberg
© Fraunhofer IBP
Elke Zimmer, State Secretary of the Ministry of Transport Baden-Württemberg visits the Department of Acoustics.
Logo Ministry of Transport, Baden-Württemberg.
© Ministry of Transport Baden-Württemberg.