Accuracy Limits of Geometric Analysis Based on Data Collection Vehicles

Many techniques are currently available for measurement and interpretation of the geometric features of the roadway. Traffic speed, pavement survey vehicles such as the ARAN, are readily equipped with highly accurate location referencing equipment, and have proven to be a time and cost effective means of collecting horizontal and vertical curvature parameters. The accuracy of a survey vehicle's combined Geographical Positioning System (GPS) and Inertial Navigation System (INS) allow for the very effective measurement of the driven path to be collected at traffic speed, and under a range of satellite interference conditions. The real world accuracy of an ARAN with combined GPS and INS system allows for a trail with a positional accuracy of under 0.5 m to be reported. Curve-fitting algorithms, used to post process collected position data, is highly capable of interpreting the location coordinates into paths of correctly assigned tangent sections and circular curves / parabolas along horizontal and vertical alignments. Factors such as vehicle wander within lanes, lane changes, and lane closures have the potential to affect the integrity of geometric data. The level of error induced by these movements is very dependent on the arc radius and arc length. This curve alignment process of combining data collected by traffic speed, survey vehicles with curve fitting post-processors, has been found to be very effective means of measuring a range of geometric policies. When planning roadway geometric surveys it is important to understand the purpose and accuracy level necessary for the different data uses. For the covering abstract of this conference see ITRD record number 201310RT334E.


  • English

Media Info

  • Pagination: 20 p.
  • Monograph Title: 2013 Conference and Exhibition of the Transportation Association of Canada - Transportation: Better - Faster - Safer

Subject/Index Terms

Filing Info

  • Accession Number: 01517943
  • Record Type: Publication
  • Source Agency: Transportation Association of Canada (TAC)
  • Files: ITRD, TAC
  • Created Date: Mar 11 2014 10:55AM