Table of Contents

1.2.5 Data reporting

Reporting interval

Network rutting data should be reported at intervals of:

  • 100 m (high speed non-contact survey methods)
  • representative of length ≤ 1.0 km, based on sample measurements at specific discrete points (manual survey methods).

Reporting parameters

Rutting for automated measurement and collection should be reported in terms of severity and extent for the left wheel path (and for the lane where available) for each reporting interval, as:

  • Severity:
    • mean rut depth (mm), to the nearest whole number
    • standard deviation of rut depths (mm), to one decimal point.
  • Extent:
    • the percentage of the length with maximum rut depths in ‘bins’ as follows:
      • rut ≤ 5 mm
      • 5 mm < rut ≤ 10 mm
      • 10 mm < rut ≤ 15 mm
      • 15 mm < rut ≤ 20 mm
      • 20 mm < rut ≤ 25 mm
      • 25 mm < rut ≤ 30 mm
      • 30 mm < rut ≤ 35 mm
      • 35 mm < rut ≤ 40 mm
      • rut > 40 mm
    • to the nearest whole number.

The mean, standard deviation and percentage values are derived from maximum rut depth samples measured at the recommended sampling intervals and frequencies in (Table 1.4).

Data must be properly referenced in order to be meaningful for use in decision making processes. Accordingly, rutting data must be reported using an established predefined location referencing system such as the Roads and Maritime Roadloc system (RTA NSW 2002). During the data collection survey, the location of significant road features such as bridges, intersections, administrative borders, etc. must be incorporated in rutting reports, to enable each 100 m segment to be uniquely referenced in terms of the road agency’s location system.

Reports of rutting severity should always show whether a taut wire or straight edge method was used, and the length of the straight edge (see Figure 1.4). Rutting reports must also clearly identify the lane surveyed and the direction of travel during the survey, as well as the date and weather conditions, and any impediment to the survey, or missing or invalid results and their cause (e.g. road works, traffic congestion, local area of wet surface, water over road, or other obstacle on the road, lane change manoeuvre for overtaking, etc.).

Figure 1.4 is a sample extract from a rutting survey report that complies with these guidelines.

Figure 1.4: Sample extract from a report on a rutting survey

Notes:

  1. Mean maximum rut depth within each 100 m section is as described in the rutting survey report.
  2. The right hand part of this pro-forma could be used to refer to ‘right wheel path rutting’, in lieu of ‘lane rutting’, or the pro‑forma could be modified to incorporate LWP rutting, RWP rutting, and Lane rutting, as required.