Measurement of road surface
Foto: Satu/VTI
We offer road surface measurements and mobile mapping using the VTI Mobile Research Platform, MRP.
VTI Mobile Research Platform is a flexible and future-proof measurement system used to describe the condition of the road surface and the road surrounding. The measurement is carried out at traffic speed and the result is not affected by the speed of the measurement vehicle.
We also perform measurements according to the Swedish Transport Administration's standards and requirements. See what is measured and calculated in standard measurement.
The properties that can be measured with the measurement vehicle are divided into the condition of the road surface and the road surrounding.
Road surface condition
The measurement is done in a non-contact way by so-called non-destructive laser measurement. A high-resolution line laser is used to collect a continuous cross profile with sub-millimetre resolution. The longitudinal profile is collected with a spot laser. It describes the roughness of the road in wavelength ranges up to 100 metres.
Positioning of the measurement is done with GNSS-INS (Global Navigation Satellite System-Inertial Navigation System) and traveled distance, which means that data can be positioned with centimetre accuracy.
Collectable data on road surface condition:
- Longitudinal profile: to assess irregularities in the longitudinal direction of the road.
- Cross profile: Up to 4 metres wide with a grid of 1×1 mm. Used to assess wear and deformation
- Cross slope: To assess water run-off.
- Curvature: Describes road geometry.
- Rise and fall: Describes road geometry.
- Megatexture: Describes short irregularities.
- Macrotexture: Describes the surface texture, important for durability, fuel consumption, safety and noise.
- Cracks and surface defects: To assess the durability of the road.
- Temperature (air and road surface), fuel consumption, noise (environmental variables).
- Open channels dedicated to optional measurement sensors that can be used for research and development.
Variables normally used for maintenance planning and condition assessment:
- rut depth
- rut area
- theoretical water depth
- distance between rut bottoms
- edge slope
- fill volumes
- irregularities using a digitally simulated straightedge
- megatexture, RMS
- IRI, International Roughness Index
- MPD, Mean Profile Depth
- cracks
- raveling
In a standard measurement (i.e. according to the Swedish Transport Administration's specifications), the following is measured and calculated:
- rut depth; max, left and right (20 metres)
- IRI; left and right (20 metres)
- curvature, slope (20 metres)
- digital images (20 metres)
- macro texture, MPD (Mean Profile Depth) in three lateral positions (1 metre)
- megatexture; two lateral positions (1 metre)
- cross slope (1 metre)
- position (Sweref99TM)
The vehicle is equipped with two lidar scanners, a 360 camera and connected to coordinates. Photo: Satu/VTI
The surrounding survey uses the latest technology, with two lidar scanners imaging the road surface and the surrounding, up to 100 m at each side of the road. This is combined with a 360 camera to create a digital twin (3D model) of both the road surface and the road surrounding – all linked to a coordinate system.
The digital twin describes the terrain around the road to within 100 metres and can be used to detect and position objects such as signs, traffic lights and crash barriers.
Surrounding measurements and digital twins can be used in many different projects and do not necessarily have to relate to the area around a road.
The possibilities are many and the measurement system is flexible. VTI has a broad expertise so do not hesitate to contact us if you have questions or specific requests.