Carrying capacity surveys

Road Consulting Oy has a KUAB FWD 50 falling weight deflectometer in its use. Similar devices have been used for capacity carrying surveys of Finland’s common road network since 1987.
The bending of the road surface describes how the road’s structural materials behave under strain from traffic. This strain caused by traffic loads is simulated with a falling weight deflectometer which measures the force targeted to the surface of the road and the bending caused by the strain. The duration of the strain caused by the falling weight deflectometer on the road structure is c. 22 ms, and it represents well the strain impact of heavy machinery traffic.
The interval of measuring points with a falling weight deflectometer can be freely chosen, and usually an interval of 50 meters is used. From the measuring results, the carrying capacity qualities of the road or street are calculated with calculation software, revealing possible deficiencies in the carrying capacity of structures. With the measuring software, the required increase in the thickness of structures in order to reach the carrying capacity requirements can be calculated for carrying out additional or improvement work.
A carrying capacity survey is a quick and low-cost way of ensuring the carrying capacity of the target.

Uses for the falling weight deflectometer:
Carrying capacity survey to gather initial information for planning



  • in a general road network
  • on streets
  • on private and forest roads
  • on yard and parking areas

Carrying capacity survey for quality control

  • paving jobs
  • land improvement jobs
  • new roads and streets

Our references include e.g.

  • Private road maintenance associations
  • Road hosts
  • The Finnish Transport Agency
  • ELY centres
  • Metsähallitus
  • Forest centres
  • Consulting companies
  • Cities, towns and municipalities
  • Forest companies