Road Condition Assessment Manual

1. PURPOSE

The purpose of this manual is give assistance to staff and contractors assessing the condition of roads throughout the Bundaberg Regional Council. The definitions and examples given provide a basis for a uniform and consistent approach to condition rating a road.

Road condition assessment enables the Council to determine the overall condition of its road network as well as identify those road assets that require repair or renewal in future years.

2. DETERMINING SEVERITY

Severity is an indicator of how bad the defect is. Any one segment may have defects at a number of severity levels. The severity level that is chosen is the one that is most predominant across the segment.

3. CALCULATING EXTENT

For the purpose of field data collection, the raw measured data will be recorded against each road segment for each of the condition distresses.

After field data collection is completed, this area (in square metres) is then compared to the total area for the segment. This yields the percentage extent of the road area that is affected by each defect. Subsequently a score of 0 to 5 can be applied to each road segment and for each condition distress.

Examples have been provided in this road data condition assessment manual.

4. SEALED ROAD DEFECTS

4.1. Sealed Road Surface Type

Surface Type Code
Asphalt AC
Sprayed Seal SS

4.2. Carriageway Code

Road Function Code
Undivided or divided road A
Divided road + Direction (In direction of Segment Travel) B
Divided road – Direction (In opposite direction of Segment Travel) C
Car Parks P
Service Roads Q
Roundabouts R

4.3. Crocodile Cracking (Fatigue)

Crocodile Cracking is is interconnecting or interlaced cracking in a road seal resembling the hide of a crocodile.

In the case of Crocodile Cracking crack severity is a function of crack width.

Table 4.3.1 - Cracking Severity
Slight Moderate Severe
crocodile-cracking4.jpg crocodile-cracking3.jpg crocodile-cracking2.jpg
Average Crack Width < 2mm Average Crack Width > 2mm & < 5mm Average Crack Width > 5mm
Table 4.3.2 - Cracking Extent
Level Degree Area Affected
0 Nil No Defects Present
1 Negligible <2% of Total Area
2 Minor 2% to 5% of Total Area
3 Moderate 5% to 15% of Total Area
4 Extensive 15% to 50% of Total Area
5 Extreme >50% of Total Area

The level of cracking is determined by calculating the percentage of the road surface effected by cracking.

cracking-calculation.png

Taking the the above road segment as an example:

The total road segment area = 100 x 6 = 600 m²
The total area affected by crocodile cracking = 2.5m x 2.5m + 0.5m x 0.5m + (5m x 3m x 2) = 36.5m²
The percentage of the road surface effected by cracking is therefore = (36.5 / 600) x 100 = 6.1%

Looking at Table 4.3.2, 6.1% corresponds to a rating of 3 for this segment

The severity score for the segment is obtained by choosing the most predominant severity level identified.

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