Highway maintenance works

The London Borough of Hounslow has a 25 year PFI for Highways Maintenance with Vinci UK / Ringway – locally known as Hounslow Highways – who manage and maintain in full our adopted highway network.

Our Borough includes the National Highways managed M4 between Chiswick and Heathrow, the A4 from Hammersmith to Cranford and other Transport for London Roads including the A30, A406 and A205. We have a Strategic Road Network to allow local traffic to move in and around the Borough, and hundreds of local residential roads. Each road type requires a specific inspection and maintenance regime which the PFI builds into its Asset Management principles.

The PFI is responsible for the maintenance of 45 Structures and there are 20 other structures in the Borough maintained by the Local Authority. The overall BCI average of the 45 Structures within the PFI is 92.10 and individual Structures are above 80 based on the latest inspections carried out in 2024.

The PFI has a five-year programme of maintenance of the Structures to keep the overall BCIav of 45 Structures above 90 and individual Structures BCI av. above 80. The Inspections are in line with the Code of Structures carried out yearly on the Structures and this programme updated in line with the outcome of the inspection.

Additionally, the PFI maintains 13,137 Traffic signs on the Network on which a 5% Audit is carried out every year to make sure the retro-reflection is above 144cd/lx/m2.

There are also 16,033 Lamp Columns on our Highway Network, and the PFI carries out Structural, Integrity and Electrical testing every six years to ensure that safety is not compromised.

Hounslow also has 21,908 Gullies on the Network; the gullies are cleansed in line with the Road Hierarchy with is based on a Link and Place matrix.

The figures in the above table are for like for like Planned and Reactive Maintenance works. As such they exclude all money spend on traffic improvement schemes which may include measure like town centre regeneration, sustainable transport schemes, and accessibility and safety schemes. This is normally funded from our LIP funding from Transport for London.

The following budget lines have been included in the headings above:

• Capital allocated by DfT:

1. Carriageway maintenance grant issued to Local Authorities since last year for additional investment for Planned Carriageway Maintenance.

• Capital spend includes:

1. Annual capital spent on carriageways renewal funded by the Hounslow PFI project.
2. Annual capital spent on footways renewal funded by the Hounslow PFI project.
3. Pothole Pledge Allocation funded by the Authority from 2018 to 2022
4. Footway Pledge Allocation form the Authority in 2025/26.

• Revenue spend includes:

1. Reactive maintenance budget funded by the Hounslow PFI on carriageway and footway defect repairs.

Programme output for Preventative Maintenance in 2024:

• Carriageways:

1. 49 locations treated equivalent to 16,604sq.m
2. Mixture of treatments including:
   • Full road resurfacing
   • Panel repair (machine lay)
   • Panel repair (hand lay)
   • High friction surfacing
3. Additional output from other significant Traffic Improvement schemes:
   • DfT surfacing grant: full road surfacing / 7,470sq.m
   • Cycleway 9 Brentford: full road surfacing / 9,500sq.m
   • Cycleway Southall Lane: full road surfacing / 3,300sq.m

• Footways:

1. 5 locations treated under planned maintenance equivalent to 2,332sq.m
2. Additional output from other significant Traffic Improvement schemes:
   • Cycleway C9 Brentford: footway relay / 4,500sq.m
   • Cycleway Southall Lane: footway relay / 2,700sq.m
   • Brentford Yorkstone Project / 3,000sq.m

Of the revenue budget, 65% is spent on footway and 35% is spent carriageway. Of the carriageway amount 75% is then spent on pothole repairs.

Preventative spend is made up of larger scale maintenance project on assets which are showing signs of deterioration but have not yet reached the Authority’s Intervention level for immediate reactive maintenance. The locations to be reviewed each year are determined by the output of our Asset Optioneering Model which uses an algorithm based on:

• the results from the yearly consistent condition surveys.
• the existing nature of the assets (geometrical size and construction make up)
• the current asset class based on a link and place categorisation
• pre-set rules for deterioration and repeat treatment over time

Reactive maintenance spend is made up of the smaller localised intervention on sections of the Network which have reached or exceeded the intervention level. These are identified as a result of Routine Safety Inspection from our trained Highway Inspector and Ad-hoc reports received from members of the public through our customer management system.

The above approach to Asset Management has received ISO 55001 certification.

Percentage of A roads in each condition category surveyed yearly

Percentage of B and C roads in each condition category surveyed yearly

Percentage of U roads in the red condition category

We carry out Detailed Visual Inspection on carriageways and Footway Network Survey on 100% of the U roads. We are ISO:550001 accredited since 2017. 

The Project Network is divided in Road Section Lengths (RSL) and Footway Section Lengths (FSL) which are surveyed each year in accordance with the latest guidance on asset management.  

Condition is monitored through: 

• Detailed walked visual inspection (DVI)looking at defect such as; surface deterioration, fretting, cracking scaring, edge deterioration, stone loss vegetation damage and delamination on carriageway and Footway Network Survey (FNS) on footways. 

and

• Mechanised vehicle mounted SCRIM & SCANNER survey equipment looking at longitudinal profile, rutting, surface friction. 

The results from the survey are then used to establish scores for key attribute for each RSL and FSL in the Project Network and prioritise intervention.  

Overall strategy

Hounslow Highways are responsible for managing the highway assets in Hounslow. The Project Network is divided in Road Section Lengths (RSL) and Footway Section Lengths (FSL) which are surveyed each year in accordance with the latest guidance on asset management.  

The surveys which include both visual and mechanised inspection are carried out by an independent accredited company in line with industry best practice. The results of the survey are then fed into our Asset Optioneering Model (AOM) which informs our planned capital maintenance programme based on the available funds, condition, construction type, and deterioration rates.  

Design solutions are selected in close collaboration with our pavement engineering consultancy focussing on the life cycle of the proposed treatments to minimise the need for repeated intervention. 

Immediate defects are identified through a mixture of punctual residents’ reports and scheduled road safety inspections done by Highways Inspectors in accordance to the roads’ hierarchy. These defects are then addressed as part of our reactive maintenance programme. 

All relevant strategies and targets are set in accordance with the Hounslow Highways Highway Asset Management Plan (HAMP) and conform with our ISO 55001 accreditation.  

The process in use to manage highway assets in Hounslow have been devised at the start of the PFI Contract to align with best practice. The quality of our approach and data is monitored each year through a stringent regime of intenral and external Audits.  

Hounslow Highways have achieved ISO 55001 accreditation status.    

Hounslow Highways work closely with Jean Lefevre Ltd, our technical advisors, to ensure both the accuracy of the survey process and compliance with the latest regulations and guidances.  

Innovation is also pushed through Early Contractor Invovlement and partnership with our surfacing Contractor Eurovia that enables us to trial and promote new products as they become avaiable. Recent example of these include the recent introduction of warm asphalts and low carbon asphalts.  

We are trialling Vaisala and Road AI to carry out Network inspections.  

There are daily war rooms taking place between the Network Management and Operations team to make sure correct type of jobs are raised.

Specific plans for 2025 to 2026

Carriageways: 

• 56 Carriageway locations are planned to be treated from the Capital funding budget in 2025 totalling 23,929 sqm from with the PFI Annual Major Maintenance Programme. 
• The DfT allocation for 2025/26 will be used to resurface a further 8 carriageways totalling 15,784sq.m including:
  • Whitton Dene which is a strategic route between Hounslow and Twickenham, facilitating easier travel between Twickenham Stadium and transport hubs in Hounslow. 
  • Chatsworth Crescent, Hounslow;  
  • New Road, Bedfont; and  
  • Holly Close, Hanworth 
• A further 4,600sq.m of carriageway resurfacing have been confirmed through the implementation of Council commissioned traffic schemes with more expected to be confirmed throughout the year 

Footways: 

• 6 Footway locations are to be treated from the Capital funding budget in 2025 totalling 1,800sq.m 
• A further 3,200 sqm of footway relay has been confirmed. 
• An additional £2million funding from the Authority Capital Fund for footway surfacing is expected to be spent in 2025/26 across 22 locations.  
• 100% of the allocation will be spent on Preventative Maintenance 

How many miles of carriageway are you planning to resurface?

• 44,313sq.m in 2025/26 based on current agreed programme 

How many footways do you plan to improve?

• 29 individual footway sections will be improved 

• Routine maintenance will continue to be carried out as required on the 45 structures forming part of the Hounslow PFI. 
• Strand on The Green river wall in Chiswick is also currently under investigation to assess the scope of forthcoming repairs. Finite scope and timescale of the works will be subject to agreement with the Environment Agency. 
• Further planned maintenance is also under review for Stourton Bridge and Kendal Bridge although these are unlikely to start on site until 2026.    
• 937 – based on an average of the total number of potholes filled over the last 5 years. 

Minimising disruption due to Street and Roadworks – Key objectives

To increase the efficient running of the highway network by minimising the disruption and inconvenience caused by road and street works and other highway events and activities through proactive management of activities on the highway. 

The introduction of the permit scheme has enabled controls not previously available under legislation to be used to improve the management of all activities on the road network through increased co-ordination and timing of works with all works promoters, including works for roads purposes. 

The scheme has provided improved control, planning and coordination of works and a more robust framework for checking and challenging activities. These measures have promoted a reduction in the total duration of works taking place within the highway and ensures that the conditions attributed to permits promote the expeditious movement of traffic through works thus reducing disruption and promoting safety at works sites. 

The scheme is to ensure journey reliability on the road network with a focus on the busy routes defined as traffic sensitive and type 0, 1 and 2 roads, that carry the greatest volume of traffic and provide important public transport routes. 

• Encouragement of partnership working between the permit authority, all Activity Promoters and key stakeholder groups in the borough 

• Enhanced coordination and cooperation  

• Provision of more accurate and timely information to be communicated between all stakeholders including members of the public 

• Letter drops, Advance Warning Signs, the relevant websites, social media etc. 

• Promotion and encouragement of collaborative working 

• Improvement in timing and duration of activities, particularly in relation to the busiest streets within the network 

• Promotion of dialogue regarding the way activities are to be carried out 

• Enhanced programming of activities and better forward planning by all activity promoters 

• To ensure parity of treatment for all activity promoters particularly between statutory undertakers and highway authority works and activities. 

• Continue developing process and procedure to ensure agreements are best reflected within the permit details to aid co‐ordination. 

• Continue to build working relationships with neighbouring road authorities to ensure coordination is effective across boundaries. 

• Continue to focus on the identification of collaborative working opportunities at the planning stages through early engagement with all stakeholders 

• Continue the coring programme to gather data and feedback performance to works promoters to better understand reinstatement compliance and their effect on the longevity of the asset. 

• Continue developing process and procedure to ensure agreements are best reflected within the permit details to aid co‐ordination. 

• Continue to build working relationships with neighbouring road authorities to ensure coordination is effective across boundaries. 

• Continue to focus on the identification of collaborative working opportunities at the planning stages through early engagement with all stakeholders.

Regular performance meetings with utilities are held to enable a shared understanding as to why non-compliance has occurred and what measures can be introduced to prevent future reoccurrences.

Also, the enforcement measures taken such as the number of FPNs and Overruns issued over a period are reviewed.

This contributes to improving the safety of road users in terms of signing and guarding whilst protecting the highway asset by ensuring the quality of works on the highway.

We have a strategy to use the PFI to test, trial and transfer any operational equipment and, depot improvements and industry techniques to more climate friendly solutions, including: 

• Electric Tools 
• Electric Vehicles 
• Electrification of the depot 
• Get it right first time to avoid re-visit 
• Efficient scheduling to reduce travelled miles on the Network  
• Warm asphalt mix 
• Rainwater harvester 
• Solar Panels 
• Additional planting additional trees in the depot and across the network 
• Full LED of all electrical assets plus dimming and trimming throughout the hours of darkness 
• High efficiency jet washing machines (50% reduction in consumption) 
• Re-use, Reduce and Recycle materials 
• Green travel plan. 
• SUDS 
• The impact from climate change require an update of Asset Management Plan and maintenance strategy in line with ISO 55001. 
• Increase demand and traffic volume on the Network. 
• Supporting modal shift 
• Varying maintenance regime based on modal shift. 
• Management of the integrity of the assets and the impact form weed growth in a biodiverse way.

The London Borough of Hounslow’s Transport Strategy was adopted at full Council on 25 March 2025. This details how the Transport Strategy will be delivered in line with TfL's policies.

The Transport Strategy clearly set out the overarching vision, objectives and focus areas for the Council.

There are 4 key focus areas of the strategy setting our vision to provide a Safe, Inclusive, Efficient and Healthy transport and highway network over the coming years.