The task of improving and maintaining road network performance for the benefit of the users is greatly helped by implementing processes that permit the assessment of road network operations. Along with a mind-set that prioritises customer satisfaction comes the need to establish performance measures that are focused on outcomes that have a direct impact on the road user (as opposed to outputs) and to track performance against those measures. The assessment of road network performance can be used to improve the effectiveness of network operations both in the short term and long term.
Performance management is an on-going activity. The use of performance measurement methods (often ITS-based) will help with setting agreed-upon network performance goals. Performance measures therefore play a big part in allocating and prioritising resources and provide the information that will help road network operators to either confirm or change current operating policies or investment priorities to meet those goals. Finally, performance measures have an essential role in reporting on the success of meeting the goals. (See Performance Measures )
Most of the factors that are highly important to road users and society will also be priorities for road network operators. However, it should be recognised that road users may have quite different perceptions of service levels as compared with the road operator. For example, a road user will note the delays due to congestion and perceive a poor quality, whereas the network operator, viewing the same situation, may highlight the very high throughput of the network and the way capacity has been maximised.
Road authorities and road network operators will be familiar with the evaluation of individual projects, but here we consider the evaluation of the total network and its overall performance in relation to service criteria. Performance assessment methods have to be both reliable and credible and must serve as a means of changing how things are done. It is therefore advantageous to establish specific performance indicators, and apply methods of cost-benefit analysis, as well as structured and quantified quality plans. (See Project Appraisal)
It is useful to consider the operational performance of a road network from three different stakeholder perspectives:
It should be noted that the first two stakeholder groups equate to the “outside–in” concept which aims to look at what the customer of the transportation network wants and needs. The third stakeholder group equates to the “inside–out” approach and considers the needs of the operator and its staff. (See "Two Views" in Road User Needs)
Road users will consider the quality of the roads dependent upon a range of factors related to how easy, safe and convenient the network is to use. It should be noted that some of these factors will be counter to those seen as important by those living and working close to roads and also may be counter to the desires and aspirations of the road administrations. General indicators applicable to all road users include the following factors:
These factors will require a consistent measurement approach so that statistics can be compared over time. For example, it will be necessary to define how the delays are to be calculated for each road or category of road, and possibly also different categories of user, and then the measurements necessary to statistically demonstrate the level of delays.
Additional factors, which are only relevant to drivers as road users, include signs, information provision, rescue service provision, rescue service operation, and particularly the speed of response to incidents. In developing countries, vehicle wear and tear is relevant.
These factors can be measured by items such as cleanliness and damage repair as well as factors associated with continuity of signs. Again, it will be necessary to evaluate how these factors are to be measured and what indicators are relevant. Some of these factors may be proxy measures; such as the number of times signs are cleaned or checked for obscuration by vegetation. The detection of incidents and speed of response to incidents is a very important factor in the operation of roads, which should be included and again it will be necessary to consider how these effects can most effectively be measured.
(See Performance Measures)
There are a number of factors, that are relevant only to public transport passengers. These include:
In addition, where the total transport system is being assessed it will be important to include the quality of the service being offered in the public transport area. This will include factors such as:
Measures in this area will also relate to accuracy of information, its availability and type of media.
(See Passenger Transport Operations)
Factors which are relevant only to freight users include:
It must also be remembered that some factors are not related to travellers, but affect those who live and work near roads such as:
Some of these factors can be directly measured, but many are of a subjective nature and can only be qualitatively assessed. Ease of use of the network must also be considered. These include factors such as:
The road user is not the only section of society affected by road quality. Society as a whole has an interest in such matters. In this area, there are a number of network factors that affect society as a whole. These include:
These effects may need to be measured for different classes of road, and possibly classes of vehicle. The effects on pedestrians and other road users must be particularly considered in this sector. Again, the factors are often interrelated. A rise (real or perceived) in road hazards may decrease the level of pedestrian activity, thus contribution to the isolation of some communities and reducing their mobility. It is important to consider how these factors can be best measured and particularly to ensure that the measures selected can be repeated over time and do genuinely reflect the changes in quality of the road network and not other external factors.
Surveys of perceived quality may be very important in this area. These will aim to cover user and society effects and can show how the operator is perceived to have addressed (or failed to address) the transport situation. It should be noted that this might indicate a divergence between the perceived and actual performance, which could point to a failure of public relations rather than a failure of the direct operations.
It should be noted that these factors also affect individuals living and working near roads. The measurement of many of the factors in this area may require the use of indirect factors and may be difficult to divorce from external factors such as weather conditions. It will be important to ensure that any measures chosen do accurately reflect the road conditions and not simply other external conditions.
These criteria include, again in no particular order:
These factors need to be added to those required to assess the users requirements to give an overall assessment of the performance of the network operation.
(See Asset Management and Planning and Reporting )
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:
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:
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:
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 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).
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:
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:
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.
There are some special situations that require specific treatment when monitoring road network performance.
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:
Where tolls are being charged the operation of the toll system is an important criterion with factors such as:
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:
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:
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.
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.