Maintenance

This section provides the following information:

• Explanation of asset life cycles and examples of activities within each phase
• The different types of maintenance activities that we undertake and why
• How we understand our network through asset knowledge
• The process we use to analyse this data to understand network need
• How we prioritise those needs into specific schemes
• Our approach to developing programmes of work

Maintenance of our assets is essential to keep the network in a safe, sustainable, and serviceable condition that delivers customer satisfaction. It is fundamental to managing risks, implementing a ‘safe system’ approach, and ultimately delivering our Asset Management Objectives.

We manage our network using a life cycle approach, which means we consider all stages of an asset’s life – from building new assets, through to maintenance and operation of existing assets, improvements to assets where specific needs are identified, and ultimately renewal or replacement of assets that are coming to the end of their service lives.

We develop life cycle plans for managing an asset, or group of similar assets, with the aim of providing the required levels of service, minimising whole life costs, and focusing on long-term needs. Individual life cycle plans for each of our asset classes are at the core of our approach to trunk road asset management planning and contain the detail that enables good practices, such as long-term cost projection, performance management, and risk management, to be applied consistently.

AMPS Note: AMPS supports the development and implementation of lifecycle plans, by providing data and analytical tools to support the planning, delivery, and recording of works across all stages of the lifecycle.

Examples of activities across our assets’ life cycles are outlined below, with further detail in ‘Our Assets’ and Appendix A to Appendix D

Asset Life Cycle

Building new assets

• Constructing new roads or bridges.
• Developing cycle lanes and footways.
• Installing new signage or lighting points.
• Planting trees and other green assets.
• Installing drainage or technology assets.

Maintaining assets

• Developing and implementing long-term plans for managing assets.
• Addressing defects such as potholes.
• Inspecting assets to establish their condition and check for wear or damage.
• Responding to incidents which affect asset performance – e.g., vehicle impacts, vandalism, fire, fly-tipping and flooding, so that defects can be fixed.
• Maintaining plants, trees and landscaping.
• Cleaning drainage channels and gullies to ensure water can drain effectively.
• Cleaning and replacing road signs and lighting.

Operating assets

• Communicating with customers about their journeys through Traffic Scotland.
• Planning to mitigate the risk of disruptions.
• Managing incidents and obstructions.
• Monitoring and responding to traffic levels.
• Keeping carriageways free of ice and snow.
• Managing diversions.

Improving assets

• Developing cycle lanes and footways.
• Removing accessibility barriers, such as installing dropped kerbs and tactile paving.
• Improving signage / junctions for schemes.
• Adapting assets such as drainage or embankments, to make them more resilient to climate change.
• Replacement assets such as vehicle restraint systems, to improve safety in the event of collisions.

Replacing and renewing assets

• Resurfacing roads to maintain their condition.
• Restructuring concrete roads to ensure their ongoing safety and reliability.
• Replacing or strengthening structures or their components that have deteriorated over time.
• Renewing road studs and markings.
• Replacing technology components, hardware and software

Making Asset Life Cycle Decisions

In each stage of the asset life cycle written in ‘Asset Lifecycle’ below together with our supply chain we make data-driven decisions about the interventions needed to maintain the asset in suitable condition, operate it effectively, or to renew, improve or replace it. Our focus is on extending the life of assets in line with the Scottish Government’s investment hierarchy. However, these decisions can also result in new assets being constructed or installed to deliver our objectives and meet customer requirements

Our approach for identifying and prioritising life cycle activities follows the five-step process below (our operational activities are detailed in, ‘Operating our Network’). Each step of this process is discussed in this Section, with further asset specific detail found in Appendix A to Appendix D.

Lifecycle Activities

1. Asset Knowledge - Gathering information through inspections and surveys
2. Maintenance - Keeping assets in a safe and serviceable condition
3. Analysis - Understanding future performance of assets based on funding scenarios
4. Scheme Development - Prioritising replacement, renewal or improvement schemes based on weighted criteria aligned to our objectives
5. Programme Development - Developing a programme of prioritised schemes including costs

Asset Knowledge

Understanding our assets enables delivery of a network that is safe and fit for purpose, especially given the scale of the Trunk Road Network, the wide range of assets that comprise it, and the natural deterioration of asset condition. We have developed a strong base of asset knowledge over time, and we continue to update and enhance this on an ongoing basis. To do so, we specify requirements for regular surveys and inspections to gather appropriate asset knowledge to support maintenance planning and decision-making.

The specific inspections and surveys carried out by our Operating Companies are outlined in the Scottish Trunk Road Network Management Contracts, including Transport Scotland Structures Manual (TSSM) and Trunk Road Information Manual (TRIM) and Traffic Scotland Operations & Infrastructure Services Contract.

These set out Transport Scotland’s requirements for asset data, inspections, maintenance, and competence to achieve both our corporate objectives as well as our asset management objectives. Clear guidance and training is provided to support delivering the required inspections and surveys in line with our requirements and industry good practice.

The following sections outline how we build a full understanding of our assets, through the inventory that makes up our network, the defects that need to be addressed through maintenance, and the inspections and surveys that inform us of safety hazards, condition of assets, and accessibility of the network

Inventory Surveys

Good quality information is fundamental for asset management, and a detailed trunk road inventory is an essential prerequisite of establishing a cost effective and adequate maintenance regime. It tells us what assets we have and where they are, and it is the foundation on which asset management is built and when analysed in combination with other data, provides crucial decision support information.

Our supply chain is responsible for maintaining the accuracy and integrity of the inventory data within AMPS to meet the requirements set out in our contracts.

Defects

It is natural for any road infrastructure to deteriorate over time. This creates defects on the Trunk Road Network that need to be managed to provide safe and reliable journeys. A defect to an asset is defined as something that:

• Causes an unintended hazard, nuisance, or danger to the users of the trunk road network
• Represents a deterioration from the normal condition
• Prevents the asset from acting in its intended manner
• Is damaged
• Is likely to increase the rate of deterioration of another asset

A defect can cause a potential hazard to network users. The level of risk is dependent on the nature and severity of the defect and the surrounding environment. Defects are divided into two categories (as detailed below) to enable prioritisation of budgets and resources, to rectify defects that require prompt attention, and support the implementation of a safe system approach.

Category 1

A category 1 defect is a defect which due to its nature and location represent an immediate or imminent hazard.

Response time

Rectified through temporary or permanent repairs, removing the hazard or by taking any other measures to protect trunk road users within 24 hours of identification, or by 6am the following day for carriageway defects. If a temporary repair has been carried out, the deferred permanent repair period is 28 days, but sometimes longer for specialist assets.

Category 2

A defect which, following risk assessment, does not represent an immediate or imminent hazard or risk of short-term structural deterioration.

Response Time

Scheduled and prioritised into programmes of work by our Operating Companies. Category 2 defects that should have been resolved as part of cyclic maintenance will be rectified within 28 days of identification.

Safety Inspections

Safety inspections are generally vehicle-based visual inspections (driven at a maximum speed of 50mph, stopping as necessary) designed to identify Category 1 defects. This includes identifying defects which impact the sightline and visibility of the trunk road network (e.g. vegetation encroaching the visibility of traffic signs). Safety inspections are also undertaken at night-time to identify Category 1 defects associated with illuminated (e.g. lighting point) and reflective assets (e.g. road studs). Structures also have three-monthly on-foot safety inspections to check parts not visible from a vehicle on the trunk road, e.g. debris building up in culverts, barrier damage to piers on the local road below. These inspections are critical to implementing the ‘safe roads and roadsides’ element of the safe systems approach.

Asset Inspections and Surveys

We use a range of inspections and surveys, with established condition scoring systems, to assess the condition of our assets and facilitate the following:

• Informing our maintenance strategies
• Identifying Category 2 defects to incorporate into future maintenance schemes
• Comparing the performance of assets across the trunk road network
• Providing information on deterioration of assets to support long-term financial planning
• Informing key performance indicators with respect to the safety and serviceability of the network

Visual condition inspections are generally carried out on foot by suitably experienced inspectors using traffic management, where required, to allow the inspectors to safely assess assets. These inspections are designed to establish programmes of routine maintenance tasks not requiring urgent attention (Category 2 defects) and capture condition data to support the identification and prioritisation of renewal schemes. The frequency of these inspections varies according to the asset.

Other methods of collecting asset knowledge include a range of machine surveys for carriageways, and specialist inspections where specific knowledge and/or equipment is required, for example electrical testing or assessment of hidden bridge components.

Further detail on asset specific inspections and surveys can be found in Appendix A to Appendix D.

Accessibility Inspections

We are committed to developing a programme to enhance and improve accessibility on the trunk road network.

Accessibility inspections are undertaken to identify any barriers to access, and are required to comply with the Equality Act and the Trunk Road Action Plan document ‘Roads for All’. This knowledge is then used to inform inclusive design in the construction, operation and maintenance of road infrastructure.

AMPS Note: AMPS contains detailed data on our assets, including condition, inspection histories and defects.

Maintenance Types

There are four types of maintenance that we undertake on the trunk road network, each with a different purpose and a range of different maintenance activities. The four types are as follows:

Reactive Maintenance

Covers a range of unplanned activities that may arise on the trunk road network, including essential maintenance to fix a defect. Examples include pothole repairs and urgent works to make other high-risk defects safe.

Cyclic

Day-to-day servicing, rather than repair, of assets to keep them operating. Examples include cutting of vegetation, cleaning of drainage systems, servicing of mechanical components, and litter picking.

Programmed Maintenance

Moderate to major work which aims to improve the condition and functionality of the asset and is planned one or more years in advance. Examples include carriageway resurfacing and replacement of bridge components.

Winter Maintenance

Activities to prevent snow and ice endangering the safe passage of pedestrians and vehicles on the trunk road network. Examples include gritting of roads and snow ploughing.

Further asset specific detail on reactive, cyclic, and programmed maintenance can be found in Appendix A to Appendix D, while winter maintenance is covered in more detail in ‘Operating our Network’

Analysis

We have a long-term responsibility to maintain the trunk road network in a way that supports our vision, aims and objectives. As with all infrastructure, the life cycle of our assets can be maximised by regular maintenance but also requires significant renewal after years of permanent use.

We combine our asset knowledge, gained through delivering the processes outlined in ‘Asset Knowledge’, with well-proven analytical techniques to help us understand the needs of the network and decide how we should invest funds and deliver activities.

This enables the development of appropriate schemes and maintenance programmes which:

• Use our well-established long-term life cycle planning approach considering all key stages of an asset’s life – from construction, maintaining, and operating of existing assets, improvements to assets where specific needs are identified, and renewing or replacing of assets as needed. The service life and renewal frequencies for our assets vary by asset class due to the function of each asset and the network risks it mitigates, as detailed in ‘Our Assets’. Appendix A, Appendix B, Appendix C and Appendix D provide detailed information on lifespan renewal frequencies for each asset class.
• Aligns with our asset management objectives and our asset management framework detailed in ‘Our Approach to Asset Management’ ensuring we plan, deliver, maintain, and improve in a consistent and efficient way.

More information on the long-term investment scenarios that we develop is outlined in ‘Investment Scenarios’.

AMPS Note: AMPS incorporates powerful tools which use asset data to support important decision-making processes and secure future investment. This includes optimisation of budget allocation between asset classes, determination of budget required to deliver specified service levels, and whole life costing of maintenance options.

Scheme Development

Investment scenarios determine the forecasted funding required at network level, as outlined in ‘Analysis’, but this then needs to be translated into potential schemes for delivery on the network. This process needs to consider the competing demands both within and across asset classes, and the financial constraints where available budgets may not be sufficient to cover all potential work required.

While most schemes are expected to be focused on maintenance, we also deliver adaptation and resilience schemes and active travel schemes. By considering the network as a whole, we look to combine these types of work where possible, for example addressing defects during adaptation and resilience schemes. This approach will provide greater efficiencies and reduce the impact of network disruption on road users, as repeated visits to the same location are avoided.

AMPS Note: ‘Everything is an Asset’ approach means the data for adjacent asset classes is readily available when making asset maintenance and investment decisions. As a result, cross-asset activities are more easily identified, bringing opportunities to share traffic management and reduce network disruption.

Maintenance Schemes

Potential maintenance schemes are developed and assessed to identify where funding should be spent on the most deserving sites that offer best value with a demonstrable maintenance need. We develop schemes based upon a range of criteria that is described in asset specific guidance and standards:

• Roads structural maintenance schemes – requirements contained within Transport Scotland's Pavement Maintenance Guidance apply
• Structures maintenance schemes – the results of assessments and inspections are analysed and processed in accordance with the Transport Scotland Risk Prioritisation tool
• Ancillary assets schemes – the requirements within Transport Scotland’s Ancillary Assets Scheme Development Guidance apply
• ITS – as defined in the Traffic Scotland Operations and Infrastructure Services Contract

Adaptation and Resilience Schemes

Transport Scotland’s Roads Delivery and Operations Directorate is responsible for delivering improvements to the trunk road network, in the form of casualty reduction schemes and climate mitigation schemes.

Casualty reduction schemes support our commitment to the safe system approach and delivering our Road Safety Framework to 2030. Climate mitigation schemes may involve rock slope remedial works, vehicle restraining system replacement, and upgrades as well as layby improvements and upgrades.

The development of schemes considers traffic volumes, length of diversion routes, potential disruption to communities, sustainability factors, road condition, and natural hazards. Larger schemes are undertaken by the Infrastructure Projects Directorate.

Adaptation and resilience schemes can be designed to mitigate a wide range of vulnerabilities, often bringing overlapping improvements to road safety (‘Our Organisation’), overall network resilience (‘Operating our Network’), and climate change adaptation (‘Environment and Sustainability’).

Trunk Road Active Travel

To increase the numbers of people walking, wheeling and cycling, our communities must put people and place before the movement of motor vehicles. New and upgraded infrastructure that makes active and sustainable travel safer, easier and more convenient is essential to meet our 2030 vision that ‘Scotland’s communities are shaped around people, with walking or cycling the most popular choice for shorter everyday journeys’.

Active travel infrastructure can come in a range of different forms, from footways that are smooth and wide enough for everyone's needs, including wheelchair users and people pushing prams, to cycle tracks that are protected from traffic. Transport Scotland funds new and upgraded active travel infrastructure through a variety of programmes.

Transport Scotland has been working in partnership with the Trunk Road Operating Companies to develop and deliver active travel schemes on the trunk road network since 2021. Funding of over £11 million between 2021-22 and 2023-24 has delivered over 24km of new or improved paths, three signalised pedestrian crossings, and funding to construct more than 26 active travel infrastructure schemes.

Scheme Identification

Our programmed maintenance work plans are developed based on asset condition data including results from inspections and condition surveys. Each asset type has defined thresholds or triggers that when reached indicates that maintenance is required. The actual need for maintenance is assessed through further site inspections and appropriate testing which are used to validate initial findings and refine appropriate treatment options.

For example, our Operating Companies identify assets that with a potential maintenance need through the following sources:

• Condition data: data gathered and held in AMPS is used to identify potential areas of maintenance need
• Defects: identified through safety and detailed inspections, and are used to inform the timing of maintenance in an area
• Route tours: used to identify areas of potential maintenance for consideration
• Accessibility inspections: where potential barriers have been identified
• Data from other surveys and inspections: the information gathered through other surveys and inspections can inform of locations where maintenance should be considered
• Other sources: includes ministerial requests, customer feedback and complaints.

Whole Life Costing

To assist in determining the most appropriate treatment option for an identified maintenance scheme we have developed a whole life costing model. This model is used to assess the economic efficiency of various potential treatment options for an individual scheme to assist us in determining the most advantageous treatment option that delivers the best value for money over the life cycle of the asset.

The use of the whole life cost model provides us with the mechanism to assess how the most appropriate maintenance is delivered at the right time whilst reducing the whole life costs of maintenance.

Scheme Prioritisation

Transport Scotland operates within the allocated budgets we receive from the Scottish Government as per ‘How Transport Scotland is Funded’, and programmed maintenance budgets are unable to fund all activities that we would like to undertake. This means different maintenance needs are competing for the same money. The available budget is spent on the most deserving sites with demonstrable maintenance needs in a manner that is consistent with our maintenance policies and objectives. We have developed and implemented a formal value management process for assessing the benefits of undertaking maintenance and the associated risks of not undertaking maintenance. The process involves deriving a value management score which subsequently informs the priority of the scheme. The factors that are taken into consideration in calculating a value management score are described below.

Value Management Score

Safety

Assess the level of risk to the road user, e.g. schemes that are safety critical or have a high level of risk will have the highest priority scoring.

Functionality

Assess the level of risk to the service either at asset or route level, e.g. route availability, journey time reliability.

Environment & Climate

Assess the impact of the scheme on the environment, e.g. noise reduction, recycling, sustainability and climate resilience / adaptation.

Value for Money

Consider the value for money of the scheme, future profiles of workload and opportunities to minimise whole life costs, e.g. invest now for savings later.

We work with our Operating Companies to apply this value management process and help us consider the relative importance of different schemes on a consistent basis. This allows us to adjust our forward programme, so we can deliver schemes earlier where they will provide greater benefits.

The benefit of a rolling value management process is that it enables review and refinements to the network and individual scheme condition throughout the year. This means that available budgets can be used to target the most deserving schemes at the right time, providing the opportunity to reduce risks across our network, reduce potential costs, and reduce network disruption from interim maintenance that may otherwise be required, such as urgent patch repairs.

Programme Development

Programmes of work are required to deliver the maintenance activities that have been described in this section, including cyclic and programmed maintenance activities. Our Operating Companies use identified future maintenance needs when developing the programmes, building on the schemes identified, assessed and prioritised in ‘Analysis’

The analysis of assessments and inspections is presented in sufficient detail to review the proposed programme of maintenance schemes. Further investigations required to clearly define schemes and provide detailed estimates are included as part of the Operating Company’s proposed programme.

All maintenance programmes are recorded within AMPS, where the Operating Companies create, and record detailed one-year programmes and financial profiles to allow activity monitoring and appropriate financial control.