Norway introduces VTI's system for dimensioning roads

Norway is proceeding with the introduction of a design tool for building new roads developed by VTI. The system is already available for use by anyone with experience of road design.

VegDim, as the Norwegian system is known, uses detailed traffic, climate and materials data to predict road wear, such as the evolution of rutting and fatigue cracking.

“VegDim will give users a good idea of the consequences of different choices. They can see the implications for road lifespan of increasing or decreasing thickness or changing the type of material at one or more layers of the road superstructure,” explains Brynhild Snilsberg of the Norwegian Public Roads Administration in a press release.

The Norwegian system is based on the design tool ERAPave PP (Elastic Response Analysis of Pavements – Performance Prediction), developed by VTI researchers Abubeker Ahmed and Sigurdur Erlingsson for client the Swedish Transport Administration.

“The Norwegians are now jointly funding the project, so it’s no surprise that they have given the greenlight. However, they have also put a lot of effort into programming to make the online version of the tool as accessible as possible,” says Erlingsson.

“Sweden has chosen a different model. Here, the system is validated and used alongside earlier tools.”

To perform a calculation in VegDim, the user enters data on the number of lanes, speed limit, amount of traffic, percentage of HGVs, percentage of studded tyres, climate, ground and frost conditions and other parameters. The digital system then calculates the predicted impact on the road and how different layer thicknesses and material types may alter this.

The Norwegian Public Roads Administration is currently preparing training material for users of the tool, but the website is already up and running.

“We hope that many people will use VegDim and share their experiences and suggested improvements with us,” says Snilsberg in a press release.

VegDim and ERAPave can also be used to assess how the lifespan of the road will be affected by changes in traffic and climate impact. This may be useful in the long-term planning of maintenance and improvements. The tool may eventually be expanded into other areas of use, such as upgrading existing roads and designing pavements for car parks and airfields.

Here you can see how the tool works: VegDim

Read more about ERAPave PP (in Swedish): Nytt verktyg för vägbyggnad från VTI