Road Network Operations
& Intelligent Transport Systems
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Performance Indicators

The primary use for performance indicators for road network operators is to provide a feedback loop to enable them both to monitor their performance and also to improve the services they provide in a way that is beneficial to their “customers” the road users and society. Therefore their use of the indicators will differ according to the local context and may require additional factors to enable the operator to make proper use of the indicators.

Some of the major reasons for adopting performance indicators include:

  • accountability: performance measurement provides a means of determining whether resources are being allocated to the priority needs
  • efficiency: performance measurement focuses actions and resources on organisational outputs and the process of delivery
  • effectiveness: performance measurement provides a link between ultimate outcomes of policy decisions and the more immediate actions of transportation agencies. It provides a means to evaluate how well we are achieving our goals
  • communications: performance measurement provides better information to customers and stakeholders on progress being made toward desired goals and objectives
  • progress: performance measurement allows periodic refinement of programs and service delivery

User requirements

The aim of network operations is to satisfy the road users’ requirements in the most cost-effective manner. It is not necessarily a simple task to balance the very different factors that are demanded by different categories of user. All these differing factors are a component of any evaluation of the quality of the performance of the network. Nevertheless, all categories of user will have some common factors that concern them which will include, (in no particular order) factors related to:

  • safety and security of users
  • travel times, particularly reliability
  • mobility and accessibility
  • stress of using the network
  • social inclusion/exclusion issues
  • noise and pollution
  • cost effectiveness

It can readily be seen that for most of these criteria there is no single measure that can be easily applied to assess their quality. Although in some cases it is possible to objectively measure the factor directly, often this is not possible and it is necessary to resort to indirect measures. Therefore a mixture of both direct and indirect measures will be needed to assess the quality of the total operation.

The indirect measures will be factors that are related to the quality under consideration but are easier to identify and measure, such as:

  • congestion on each link in a network
  • network delays (at different times of day)
  • network capacity
  • variation in travel time
  • accident rates
  • transportation costs for users and road network operators
  • ride quality (i.e. how good the surface is – which may differ for different classes of vehicle)
  • network quality (i.e. how easy it is to use)

It is particularly important that the measures reflect the needs of all classes of user, paying particular attention to special groups of user such as Public Transport and freight users so that the results are applicable to all.

Note that these factors deliberately exclude any system and infrastructure maintenance that does not directly affect the customer. The factors therefore will include items such as road maintenance activities causing delays, but will exclude items such as the life left on particular assets as this is of no immediate consequence to road users (even though it may be critical to the performance of the road administrations activities in maintaining their assets).

Network Operator requirements

Many of the measures used to assess the quality of performance for users will be directly relevant for road network operators. However, in addition factors related to the maintenance of the network will need to be included such as:

  • winter maintenance operations
  • response to adverse weather conditions
  • value for money factors
  • costs
  • flows of different categories of vehicle, including axle weights
  • response to user questions
  • advice on traffic and road conditions
  • advice on prospective network changes
  • amount of upgraded network
  • time since major maintenance of the network

Data gathering

Data and information on road network performance can be collected manually or automatically.  It is necessary to consider factors such as the act of data gathering itself and the frequency and quality of data gathering. With careful planning an ITS application can often be designed to provide data for performance measures as a form of continuous monitoring. (See Performance Measures) Similarly the level of patrols along roads both to assist in traffic and incident management and also to collect assessment data is important.

Measurements required

It is vital that the measures employed must be simple to use; it must be easy to obtain accurate and reliable information; and it is preferable to use data that is already available than employ additional resources to collect it. The main aim is to quantify the quality of the transportation system and identify those areas where improvements are most needed to bring the overall quality up to an acceptable standard. (See  Evaluation)

It is important to recognise that the measurement of the factors outlined above is not necessarily a simple task in itself. Some are relatively straightforward and can be clearly specified. These will include factors such as journey times and accident rates. But others are much more subjective and need to be carefully assessed.

It is recommended that these factors be grouped into three sets related to road users, society or network effects (primarily those factors that affect society as a whole and those living and working on or close to roads) and road owners or road network operators. It should be noted that safety is a major indicator in all categories as this affects everyone, not only those using the roads directly.

It is also important to recognise that there are three distinct types of measure that will need to be made. These may be summarised as:

  • direct measurements
  • measurements of related factors (indicators)
  • subjective assessments

Each of these has quality and accuracy implications. In general, direct measurements are more accurate and reliable. The use of indicators requires some subjective assessment and therefore is a less accurate measure of the particular factor. Lastly the subjective assessment of factors, whilst very important for many cases, cannot, by its nature be as objective as the first two measures.

All performance indicators are likely to need significant interpretation and must be set up with great care. For example, an indicator of bus service performance may be the percentage of buses arriving late at their destination. An alternative could be the total number of minutes all the buses on the service are late. At first sight, these measures are very similar yet they could hide very significant differences in performance, for example if the service is in fact unreliable and some services are very late whereas most arrive on time. Thus, it is important to select the measures to be used as performance indicators with great care and with due regard to the factors that are important to the different categories of stakeholder.

Special situations

There are some special situations that require specific treatment when monitoring road network performance.

Tunnels & Bridges

The effect of an incident in a tunnel or on a major bridge can be much more severe than a similar incident elsewhere. It is therefore particularly important for traffic operators to be able to identify potential hazards and deal with them quickly. The facilities are usually managed in a similar fashion to other parts of the network but with specific facilities applicable to these areas.

The additional operational management of these facilities may be summarised as:

  • identification of potential hazards
  • management of any hazards and rectification
  • management of the electrical and mechanical services in tunnels and traffic management during their maintenance or failure
  • management of traffic during maintenance operations


Where tolls are being charged the operation of the toll system is an important criterion with factors such as:

  • level of evasion
  • speed of toll collection

City Integration

The integration of all modes of transport within cities is frequently an objective of the road owners. The success of policies designed to manage the total networks may require special consideration with the collection of factors related to issues such as:

  • minimise congestion
  • minimise hazards at junctions between networks
  • integration of networks
  • minimise interchanges and interchange times
  • lower travel times on public transport than private transport

Emergency Operations

The response of the operator to emergency or major events is often a critical factor in the perceptions of users to the quality of the service provided. It is therefore important that emergency plans are made and regularly updated. These will include plans for the response to major emergencies such as major traffic accidents, which result in total closure of part of the network for an extended period and major maintenance activities. (See  Emergency Plans) For these items, factors will be needed to assess the level of preparedness for such events including:

  • planned updates schedule
  • emergency procedure plans

Police Activities

The enforcement of road traffic regulations may be an important factor in road safety and operational matters. (See  Policing / Enforcement and Enforcement Systems)The level of enforcement may also have some negative effects on road user behaviour. The following factors may be relevant to the operation of some authorities.

  • number of enforcement equipment
– speed cameras
– red light cameras
– toll enforcement systems
  • number of prosecutions for road traffic offences

Use of statistics

Each road operator will need to assess how they wish to make use of the statistics generated by these measurements. Apart from their use to demonstrate the success or failure of the enterprise and the changes that take place year by year, the measures can be used as a positive management tool to improve services and cost effectiveness year on year.

One very simple concept is for road network operators to consider the long-term effects of their operations on each of the measures. This can indicate where very significant improvements in the quality of the network can be made over time. It is necessary to identify those factors that have an on-going effect and those that are merely transitory and then decide if it is appropriate to move resources towards the long-term effects.

The quality measures should demonstrate the effectiveness of this approach over time. It is therefore important that these quality measures should be seen as long-term measures to be repeated, which can demonstrate a continuing development of improved services over a significant period. (See  Performance Measures)

The use of long-term strategies to exploit the statistics gathered is particularly important for private toll road operators who need to justify the level of their tolls for their users and for private public transport operators who wish to increase the patronage on their services. But it is still a very valuable concept for public sector road network operators and public transport providers who may also be required to consider the value of “uneconomic” services which society requires the operator to provide for social and other reasons.


Reference sources

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