Table of Contents

3.3 Performance Monitoring and Prediction

The common approaches used by road agencies to predict the service life of other assets include:

  • manufacturers’ performance data
  • professional judgement of road agency staff
  • literature reporting service life experienced by others
  • documented road agency experience: for example, historical databases or other records of asset performance and service life
  • life-cycle cost analyses to compare the performance and costs of alternative components
  • predictive models or management information systems to support the management of these assets.

Guidelines for predicting the performance of specific road-related assets are presented in Table 3.3.

Table 3.3: Performance prediction for other assets

AssetAsset life-cycle (physical) performance
‘failure’ mode(s)
Predictability of physical service life of assetData required for monitoring
Roadside vegetation –- general
(incl. vacant land, medians and verges)
  • Dying vegetation
  • Unstable vegetation
  • Excessive growth into clearance envelope
  • Excessive growth creating fire fuel load
  • Litter accumulation
  • Weed infestation
  • Insect infestation
  • Infestation by feral animals
  • Storm damage
  • Professional judgement based upon local horticultural experience
  • Variable due to seasonal variations
  • Fuel load
  • Health of vegetation
  • Weed/feral animal infestation
  • Clearance envelope
  • Litter
Conservation areas

As above plus:

  • loss of population due to health, habitat or predator issues
  • As above
  • Number and health of species population
Landscaped areasAs above
  • As above
  • Reference landscape plan
FirebreaksExcessive growth creating fire fuel load
  • As above
  • Reference agreed standard of firebreak with fire authorities and land management agencies
Roadside sculptures and formsEnvironmental deterioration of surface condition and/or structural integrity
  • Prediction of physical performance will be specific to the design of the individual treatment, monitoring and maintenance regime
  • Surface and structural condition
Heritage assets in road reserveEnvironmental deterioration of surface condition and/or structural integrity
  • Prediction of physical performance will be subject to the site-specific maintenance plan
  • Surface and structural condition
Roadside rest areas – toilets, furniture, shelters, parking areas
  • Deterioration of access/paving
  • Deterioration of furniture/facilities
  • Malfunction of services (lighting/water/ sewerage)
  • Unstable vegetation
  • The physical performance of components (e.g. Furniture) may be estimated based upon prior local experience
  • Condition and serviceability of facilities
Transit interchanges, park and ride facilities
  • As for roadside rest areas, plus:
    malfunction of passenger information services (timetable displays etc.)
  • The physical performance of components (e.g. Furniture) may be estimated based upon prior local experience
  • Condition and serviceability of facilities
Culverts
  • Abrasion/scour of invert
  • Corrosion of steel culverts
  • Obstruction due to debris/siltation
  • Structural failure under loading/settlement
  • Differential settlement
  • Leakage
  • Physical performance predicted based upon time-series of condition data of similar structures in similar environments (using structures data base)
  • Clear waterway
  • Entry and exit conditions
  • Wall thickness*
  • Condition of invert
Catch and Table drains
  • Scour, siltation, debris or vegetation growth affecting flow
  • Predictions based on local experience and monitoring
  • Clear waterway
Kerb and gutter
  • Scour of invert
  • Obstruction due to debris/siltation
  • Differential settlement of sections causing ponding of water
  • Leakage into pavement
  • Physical performance not predicted.
  • Long life asset generally superseded by road improvements
  • Clear waterway
  • Continuous free draining invert
Drainage pits
  • Damage to lid
  • Obstruction due to debris/siltation
  • Physical performance not predicted
  • Long life asset generally superseded by road improvements
  • Clear pit and entry and exit conditions
Subsoil drains
  • Siltation
  • Crushing of subsoil drain due to wheel loads
  • Observation and local experience only
  • Outlet flows
Batter drains
  • Erosion of batter
  • Drain dislodged from embankment
  • Leakage from section joints or worn invert of batter drain
  • Observation and prior local knowledge of performance of similar materials and components
  • Continuity of drain
  • Drain invert
  • Signs of scour
Floodways and fords
  • Washouts and debris after flooding
  • Predictable after major storm events
  • Pavement condition and debris accumulation after major storm events
Pumping stations
  • System-specific characteristics
  • Physical performance predictions are system-specific
  • Flow rate
  • Power supply and functionality of switching equipment
Sedimentation basins and bio-treatment ponds
  • Siltation of basin
  • Death of plant & aquatic life due to excess pollutant levels
  • Inadequate water in dry conditions to sustain plant life
  • Physical performance predictions are system-specific
  • Outlet water quality
  • Water level and degree of siltation
  • Plant/ biological health
Gross pollutant traps
  • Siltation
  • Overloaded capacity
    system-specific characteristics
  • Physical performance predictions are system-specific
  • Outlet water quality
Leachate treatment plant
  • System-specific characteristics
  • Physical performance predictions are system-specific
  • Flow rate
  • Outlet water quality

Roadside signs

  • regulatory
  • warning
  • guide
  • parking
  • Fading of sign face, loss of colour, legibility and retro-reflectivity
  • Damage and vandalism
  • Sign obscured by vegetation
  • Functional obsolescence of sign or sign scheme design
  • Professional judgement based upon local experience plus manufacturers’ data on materials’ life
  • Condition
  • Legibility
  • Reflectivity

Guide posts

Snow indicator poles

Flood depth indicators

Kilometre posts

  • Reduced conspicuity due to dull/dirty paint and/or lost or degraded reflector
  • Loss of posts by damage or vandalism
  • Local experience of replacement rates
  • Condition
  • Visibility
  • Reflectivity
Poles and support structures for signs and lighting
  • Shear failure at base due to corrosion and/or fatigue cracking
  • Damage from vehicle crash or vandalism
  • No predictions for posts and minor supports
  • Physical modelling of major structures based upon design and time-series of condition data from structures database
  • Condition and cleanliness

Pavement demarcations

  • pavement markings
  • painted lines
  • long life markings
  • audio-tactile (rumble) strips
  • pavement symbols
  • coloured pavement surfaces
  • raised reflective pavement markers
  • Retroreflectivity
  • Wear
  • Damage/loss
  • Pavement maintenance /resurfacing
  • Professional judgement based upon local experience, traffic composition and manufacturers’ data on material life
  • Condition
  • Visibility
  • Reflectivity
Street lighting
  • Lamp failure (end of globe life)
  • Power supply failure
  • Functional obsolescence of lighting scheme design
  • Technical obsolescence of lamps, circuitry or power source
  • Professional judgement based upon local experience, manufacturers’ data on life of components and monitoring.
  • Operation(1)
  • Power supply(1)
  • Power usage

Traffic signals

Traffic sensing loops

Traffic signal controllers

  • Lamp failure (end of globe life)
  • System failure due to damage/deterioration of controller
  • Reduced conspicuity due to dirty lens
  • Damage from vehicle crash or vandalism
  • Technical obsolescence
  • Professional judgement based upon local experience, manufacturers’ data on life of components and monitoring
  • Operation(1)
  • Power supply(1)
  • Power usage
  • Condition and cleanliness

Electronic communications infrastructure:

  • CCTV camera equipment
  • electronic signs
  • electronic speed zones (incl. school zones)
  • emergency help phones
  • height gauges
  • ice detection and warning stations
  • SCATS regional computers
  • smart bus signs
  • traffic counting loops and data station
  • overhead lane controls (incl. tidal flows)
  • tidal flow controls
  • in-pavement lights
  • school speed zones – electronic
  • red light cameras
  • speed cameras
  • bus lane cameras
  • System failure due to damage/deterioration
  • Damage from vehicle crash or vandalism
  • Technical obsolescence
  • Professional judgement based upon local experience, manufacturers’ data on life of components and monitoring
  • Operation(1)
  • Power supply(1)
  • Condition and cleanliness
Roadside barriers and median barriers (wire rope and other)
  • Environmental deterioration of barrier surface appearance and supports (especially timber supports)
  • Deterioration of anchorage conditions
  • Damage from vehicle crash or vandalism
  • Local experience regarding environmental degradation of timber support posts
  • Condition
  • Appearance
Movable medians
  • Failure of connectivity between units
  • Failure of relocation equipment and vehicle
  • Physical performance predictions are system-specific
  • Operational condition
  • Appearance
  • System-specific maintenance plan
Weighbridges
  • System-specific
  • Physical performance predictions are system-specific
  • Operational condition
  • Calibration
  • System-specific maintenance plan
HV inspection areas
  • Pavement failures under concentrated loading
  • Pavement management system model may be used to give indication
  • Pavement condition
  • Level of use
Weigh-in-motion devices
  • System-specific
  • Physical performance predictions are system-specific
  • Operational condition
  • Calibration
  • System-specific maintenance plan
Noise walls
  • Deterioration of surface integrity ( e.g. Cracking)
  • Deterioration of quality of appearance of surface finish
  • Predictions are based upon condition monitoring and analysis of like-types in structures database
  • Appearance
  • Surface integrity
  • Structural condition(2)
Boundary fencing of road reserve
  • Environmental deterioration of fence materials and loss of integrity (especially timber posts)
  • Deterioration of appearance
    damage or vandalism
  • Predictions based upon local knowledge of patterns of deterioration, particularly timber components in local environment
  • Condition
  • Appearance
Pedestrian fences
  • Environmental deterioration of fence materials and loss of integrity (especially timber posts)
  • Deterioration of appearance damage or vandalism
  • No predictions of physical life – commonly replaced due to fence damage
  • Condition
  • Appearance
Rock protection fences
  • Environmental deterioration of fence materials and loss of integrity (especially timber posts)
  • Deterioration of appearance damage or vandalism
  • No predictions of physical life – commonly replaced due to fence damage
  • Condition
  • Appearance
  • Build-up of material behind fence
Bicycle paths
  • Deterioration of path surface and ride quality
  • Root damage to path
  • Intrusion of abutting vegetation
  • Damage or vandalism to path, signs or furniture
  • Simplified PMS modelling can be applied at network level
  • Condition of path
  • Signs, furniture and pavement markings
  • Vegetation clearance
Pedestrian paths
  • Deterioration of evenness of path surface
  • Root damage to path
  • Intrusion of abutting vegetation
  • Differential settlement of concrete paving slabs
  • Simplified PMS modelling can be applied at network level
  • Condition of path
  • Signs, furniture and pavement markings
  • Vegetation clearance
Railway crossings
  • Failure of train sensing mechanism
  • Failure of gate closing/opening mechanism
  • Failure of warning lights and bells
  • Physical performance predictions for crossing components are system-specific
  • Condition of roadway
  • Signs, furniture and pavement markings
  • Performance of gates and warning systems (sometimes monitored by remote sensing)
Utilities and other 3rd party owned assets (in road reserve – in pavement or roadside) including service covers
  • Environmental deterioration of service conduit (e.g. Overhead lines damaged by wind, water pipes ruptured by ground movements)
  • Damage to access paths by vehicles
  • Failure at point of service junction to abutting property
  • Physical performance predictions are specific to each utility service
  • Condition of access
  • Signs of impacts (of service operations or maintenance) on the road reserve and road pavements
Irrigation channels
  • Rupture of channel and uncontrolled flow affecting road formation
  • Local knowledge – not modelled
  • Condition of access
  • Signs of impacts (of service operations or maintenance) on the road reserve and road pavements
Navigation lights on bridges
  • Power outage
  • Lamp failure
  • Location-specific
  • In accordance with system specification and operations plan and in liaison with responsible maritime authority.

Tunnel services

  • ventilation
  • lighting
  • dewatering
  • fire fighting
  • PA/communications
  • signs
  • System-specific
  • System -specific
  • Tunnel environment (air quality, temperature, smoke, drainage water, visibility) and operation of tunnel services assets in accordance with system specification and operations plan
  1. Remote monitoring.
  2. Structural details recorded in structures inventory and inspections in accordance with structures inspection policy.