Laplace distribution models for road topography and roughness
Journal article, 2017

Gaussian models are frequently used for road elevations. However, these models are often only valid for short sections of the road. Here we present a comprehensive approach to describe various aspects of road surface/elevation by using extensions of Gaussian models arising from random gamma distributed variances. These random variances result in the Laplace distribution and thus we refer to the so defined models as Laplace models. The approach is shown to perform well in modelling road topography, road roughness and multi-valued responses of forces and bending moments containing transients. The different Laplace models are presented together with numerical examples and Matlab code for simulation.

ISO spectrum

fatigue damage.


international roughness index

generalised Laplace distribution

road roughness

autoregressive process



road profile

power spectral density

non-Gaussian process


Pär Johannesson

Krzysztof Podgorski

Igor Rychlik

University of Gothenburg

Chalmers, Mathematical Sciences

Int. J. Vehicle Performance

Vol. 3 224-258

Areas of Advance


Subject Categories


Probability Theory and Statistics