Simply put - Potholes are formed by water penetration through the blacktop surface of the road/ highway through cracks generated by traffic. When the temperature drops, the penetrating water freezes, subsequently expands and causes the running surface to shatter. When the ice melts, it leaves a void below the road surface, which caves in under the stress of vehicles and eventually forms a pothole.
Snow and ice are the worst weather conditions for exacerbating existing road defects, due to the repetition of the freeze-thaw process.
The impact of 2 extreme (back to back) Scottish winters in 2009 & 2010 created further misery on Scotland's roads & footpaths for both motorists and cyclists alike.
Scotland Transerv, as Trunk road Maintenance Authority don't appear to have any shame given the NCN 7 issue is known to them:http://www.inverness-courier.co.uk/Feat ... 102012.htm
This neglect appears to extend between Dalwhinnie and Calvine. - The Scottish Route Development page at http://www.sustrans.org.uk
states: “The path does have some surface issues, but is easily passable along its whole length with a mountain bike or hybrid".
I haven't ridden this section, but the news article seems to suggest that poor engineering has led to drainage gravel being scoured onto the newly laid (2011) black top - not ideal for skinny tyres. http://www.transportscotland.gov.uk/fil ... _2011_.pdf
Cycling by Design 2010 (Revision 1, June 2011)
10 Construction and Maintenance
Construction and maintenance are important aspects of any cycle facility. The quality of
surfaces and edge details are particularly important to cyclists, who are more vulnerable to
minor defects and poor construction than other road users. It is therefore important to
ensure that construction details and materials for the cycle facility are appropriate and that a
suitable maintenance regime is established.
Designers should ensure that the the materials and level of construction specified for cycle
facilities are appropriate for purpose and that over specification does not lead to needlessly
expensive facilities. However, the specification used should seek to ensure the least
amount of future maintenance required as possible.
10.2.2 Surface Condition
The surface of a cycle facility should have an even profile, be free of major defects and
conform to the Specification for Highway Works. Where necessary, defects should be
rectified in accordance with the maintenance requirements.
Complaints should focus on the referenced obligations that the Contractor appears to be defaulting on.