Ask
the Contract Director!
We understand that as members of the public, you probably
have a lot of burning questions regarding the roads around Buckinghamshire.
Well, we’re giving you the opportunity to get your questions answered by
Transport for Buckinghamshire’s Contract Director!
In each blog post in this exciting new series, we will be
focusing on a different frequently asked question. This week, we’re answering:
How do you decide which potholes to repair?
Buckinghamshire County Council’s 3,200km highway
infrastructure is its most valuable asset, valued at £4.2 billion. It provides
a vital transportation network for both businesses and private users.
Under our Routine Maintenance Service Principle, Transport
for Buckinghamshire (TfB) is to maintain the highway infrastructure in a safe
and serviceable condition for its users, whether driving, walking or cycling.
In order to identify any defects on the highway, regular inspections are
carried out by TfB Highways Inspectors and Local Area Technicians (LATs).
Carrying
out inspections
Highway Safety Inspections are supplemented by other
inspections and assessments carried out in line with national standards and/or
good practice, including but not limited to:
- Inspections
undertaken in response to specific matters identified through correspondence
(e.g. Fix My Street reports)
- Specialist
inspections of certain assets within the highway boundary (e.g. street lighting
and structures)
- Technical
assessments of carriageway condition, generally undertaken using machine based
equipment
- Streetworks
Inspections
The frequency for safety inspections of individual roads is
based upon the Carriageway Maintenance Hierarchy adopted by Buckinghamshire
County Council, which considers:
- Road
Category: Strategic roads, main distributer and secondary distributor roads are
inspected on a monthly basis whereas local link-roads are inspected on a
quarterly basis and local access roads are inspected annually.
- Traffic
use, characteristics and trends
- Characteristics
of adjoining roads
- Wider
policy or operational considerations
Although the road category within the hierarchy, in
combination with traffic use, will determine the inspection frequency, site
specific factors may contribute to a decision to temporarily or permanently
increase or reduce the frequency of the inspection of a specific location.
Factors that may contribute to this kind of decision may include accident rates
and unusually high defect levels.
Identifying
a defect
Like many authorities, TfB used to repair potholes based
on their ‘size’. A large pothole with jagged edges would be repaired more
quickly than a small one, regardless of its location. However, we now follow a
risk-based approach when it comes to repairs, meaning that we take in to
consideration:
- The
risk posed to the public
- The
extent, depth and surface area
- The
volume and speed of traffic of the road the defect is on
- The
location, such as junctions and bends
- Forecast
weather conditions
Applying this risk based approach is beneficial to road
users, as it means that we are able to target our resources to higher risk defects.
Lower risk defects can be fitted in to repair programmes that allow us to
operate far more efficiently.
Defect
Categorisation
TfB’s Safety Inspection Policy defines defects in three
categories:
Emergency
(Category E) – Those that require prompt attention because
they represent an immediate hazard.
Emergency defects will be permanently repaired or made
safe at the time of the inspection, if possible. Making the defect safe may
constitute displaying warning notices, coning or fencing off to protect the
public from the defect or other suitable actions. If the inspection team are
unable to effect a “make safe” then we do have repair teams available to attend
within the 2hr time frame.
Category E defects will be permanently repaired within 28
working days if a permanent repair was not possible upon the first visit.
Category
1
– Those that require priority
attention because they represent a potential risk to road users or reduce the
reliability of the highway.
Category 1 defects will also be permanently repaired or
made safe at the time of the inspection, if possible. If it is not possible to repair
or make safe at the time of the inspection then an appropriate repair will be
carried out within two working days
of the identification of the defect and a permanent repair made within 28
working days.
Category
2 – All
other defects.
Category 2 defects are those which are deemed not to
present an immediate hazard and which can be repaired within longer timescales
– they are either programmed for repair within 28 calendar days or included in
a forward works programme. Category 2 defects are categorised according to
priority:
- High
(Cat 2H)
- Medium
(Cat 2M)
- Low
(Cat 2L)
Inspectors are able to determine which sub-category the defect
falls into by using their Safety Inspection Guidance Manual which provides
examples of defects that may be encountered on the network and their potential
categorisation. However, our on-site assessment will always need to take
account of other particular circumstances. The inspector will also take into
consideration the likelihood of further deterioration before the next scheduled
inspection, and where this is a high probability, a higher classification may
be determined.
Minimum
Investigatory Levels
It is recognised that on any highway network a multitude
of minor defects will exist which do not pose any risk to either the safety or
the reliability of the highway. As a result, it would be impractical and inefficient
to use limited financial resources to undertake repairs. These types of defects
are described as ‘not meeting the Minimum Investigatory Levels’, which for
potholes is defined as 40mm or under in depth and less than 300mm across in any
direction.
Any defects that do not meet the Minimum Investigatory
Levels will be recorded if the inspector deems this appropriate (for example,
where a cluster of such defects may form a potential preventative maintenance
scheme in the future). These kinds of
defects will be recorded as Category 2L defects.
To
find a more detailed copy of our Defect Risk Assessment, visit the web page
here.
