FOI Request - Road Condition Categories
1. Please provide the area in m2 of carriageway in the following 3 categories (if area data is not available please provide lengths in km and a nominal width): Strategic Roads, Classified Roads (anything not strategic, but classified), Local Roads (unclassified roads). Further split into Urban & Rural
(i) Green (resurfaced in the last 2 years)
(ii) Green - good condition
(iii) Amber - some deterioration present
(iv) Red - requires maintenance
2. Please provide a summary of how this information was formulated (the source of the data, the processing methodology, sample size, etc.)
3. Please provide an evaluation of the accuracy of the data.
4. If you usually classify your road network and its condition differently, please provide a summary of how you usually do this.
1. The closest data we have is the SRMCS RCI (Scottish Road Maintenance Condition Survey, Road Condition Indicator). This reports road condition in Red/Amber/Green categories broken down by Class (A, B, C & Unclassified) and Environment (Rural/Urban). The data is not broken down by Hierarchy, nor does it include a “Green (Resurfaced in the last 2 years)” category. The latest data which we have is the 2012-14 RCI (copy here) which is based on 2 year’s worth of surveys (2012-13 and 2013-14) for A, B and C class roads, and 4 year’s worth of surveys (2010-11 through to 2013-14) for unclassified roads. The data is reported in both lengths and percentages – to convert this to area you may use the following average road widths:- A Class (urban) = 8.76m, A Class (rural) = 6.66m, B Class (urban) = 7.37m, B Class (rural) = 5.88m, C Class (urban) = 7.54m, C Class (rural) = 4.63m, Unclassified (urban) = 6.38m, Unclassified (rural) = 4.14m.
2. As mentioned above, the source of the condition data is from the SRMCS survey. The SRMCS survey covers 100% of A Class roads, 50% of B & C Class roads and 10% of unclassified roads each year (in one direction). The road widths are derived from our digitised road network.
3. The SRMCS survey is carried out using a TRL accredited Scanner vehicle which ensures both accuracy and consistency across Scotland.
4. Our road network is classified by both road classification and hierarchy however the RCI results are only available by classification.