PerRoad Software

Perpetual Pavement Design Software
The APA offers two versions of its software for the design and analysis of Perpetual Pavements. Both versions of the software are available as free downloads.

PerRoad 4.4
PerRoad LogoPerRoad is uses the mechanistic-empirical design philosophy. The program couples layered elastic analysis with a statistical analysis procedure (Monte Carlo simulation) to estimate stresses and strains within a pavement. Version 4.4 provides design results as percentile responses and as conventional designs with transfer functions. In order to predict strains that would prove detrimental for fatigue cracking or structural rutting, PerRoad requires the following inputs:

  • Seasonal pavement moduli and annual coefficient of variation (COV)
  • Seasonal resilient moduli of unbound materials and annual COV
  • Thickness of bound materials and COV
  • Thickness of unbound materials
  • Load spectrum for traffic
  • Location for pavement response analysis
  • Magnitude of limiting pavement responses
  • Transfer functions for pavement responses exceeding the user-specified level for accumulating damage

Click here to learn more about Perpetual Pavement design and PerRoad 4.4 software.

Download PerRoad 4.4 | Online Help and Guidance

PerRoadXpress 1.0
PerRoadXpress is an easy-to-use, all-on-one-screen program for designing Perpetual Pavements for low- and medium-volume roads and parking lots. The designer chooses a type of asphalt cement. PerRoadXpress then allows the designer either to use defaults for traffic and soil, or to input the actual values if they are known. Granular base thicknesses from 0 to 10 inches are included. The software quickly provides the user with a recommendation for the total thickness of asphalt pavement needed for a particular situation. PerRoadXpress was developed in response to requests by public works officials and owners of commercial property.

Download PerRoadXpress 1.0