Dunedin High Speed Data Survey

Dunedin City Council
Type of Testing: 
  • High Speed Data Survey including: Roughness, Rutting and Texture
  • Validation and Annual Survey Report
Project Details: 

The high speed road condition survey was required along Dunedin City Council’s entire sealed road network totalling approximately 2000 lane kilometres. The contract commenced in 2013 and data was collected on an annual basis allowing the City Council to monitor the condition of their network.

The survey was completed utilising our Laser Crack Measurement System (LCMS) equipment. The LCMS is innovative new technology that uses two scanning lasers scanning 4096 transverse points across the full 4m lane width of the road and taking a measurement every 5mm longitudinally. This wealth of laser data allowed us to meet contract requirements and allowed for additional data sets such as automatic crack and pothole detection to be provided at a later date.

Before the survey commenced, the survey equipment and personnel had to undergo a rigorous validation to prove suitability and repeatability against reference device data and historical data (along a 10km loop). But the checks didn’t stop there, with routine validation checks being carried out each day.

"Dunedin’s network is challenging with a lot of narrow, steep roads to contend with including the world’s steepest road – Baldwin Street" says Diana Scruby, Division Manager. "The survey had to be undertaken between March and the end of May which meant that the bad weather was another challenge we had to contend with."

The Survey Team were local to the area and their knowledge gave us a greater understanding of which areas to prioritise as they were prone to frost / snow or were in valleys which tend to stay damp for long periods of time. This knowledge was valuable to ensure we met contract deadlines.

Quote from the Client: Jim McQueen, Roading Asset Engineer for Dunedin City Council:

"I am pleased with the way the survey has been carried out in all three years. We have historically carried out the roughness and the rating surveys in the period from March to May and choose to keep the same time each year for continuity. This does mean days are getting shorter and there is a risk that weather might affect progress. DCL have been focussed on timely completion and mitigated this by double shifting at the start when the weather was good. The weekly reports kept me informed of progress. The 10km loop surveyed at the set up stage and compared with previous surveys provided confidence the equipment was measuring correctly. This reflected in the final network result with Smooth Travel Exposure continuing to follow an expected steady positive trend."