Why do we need to identify problems?

A clearly specified list of problems is the most suitable basis for identifying potential solutions. Problems can be identified, both now and in the future, as evidence that objectives are not being achieved. However, objectives are often rather abstract, and it may be easier for members of the public to understand a strategy based on clearly identified problems. This problem-oriented approach to strategy formulation is an alternative to starting with objectives, but does still need to be checked against the full list of objectives.

What types of problem are we concerned with?

One of the easiest ways of specifying problems is by reference to a set of objectives (Section 7). This enables the question ‘how do we know we have got a problem?’ to be answered more easily. For example, the efficiency objective relates to problems of congestion and unreliability; the safety objective to accidents. The two concepts, objectives and problems, are two sides of the same coin. We can start either with objectives or problems and come to the same conclusions. The box shows the problems which are considered in the Policy Guidebook.

How can we decide if a problem is occurring and how serious it is?

Problems may be identified in a number of ways:

Consultation

People can identify the problems that they encounter when travelling and which result from other people travelling. Transport providers can be consulted about the operational problems which they face. This is a key element of the participation process (Section 5). People will naturally have more reliable views about current problems than those predicted to occur at some future date. Problem identification through consultation is therefore of most use for current problems.

Objective analysis

Objective analysis of problems requires the adoption of an appropriate set of indicators and targets (Section 7). When a condition is measured or predicted to differ from a threshold, then a problem is said to exist. A range of thresholds can be set, so that problems may be graded by severity. Thus, for example, noise levels which exceed, say, 65dB(A), 70dB(A) and 75dB(A) could be classed as ‘slight’, ‘moderate’ and ‘severe’ noise problems. When thresholds are defined, they can be used, with current data, to identify current problems. Given an appropriate predictive model, a similar exercise can be conducted for a future year. This is shown in the feedback loop from Predict Impacts to Assess Problems in Section 6.

Monitoring

Regular monitoring of conditions, using similar indicators to those for objective analysis, is another valuable way of identifying problems, and is covered further in Section 15. As well as enabling problems, and their severity, to be specified, a regular monitoring programme enables trends to be observed, and those problems which are becoming worse to be singled out for treatment.

Why is it useful to determine the severity of problems now and in the future?

If problems are identified through consultation, the city authority is able to determine the areas of concern for citizens. This will in turn help to confirm that they have selected the right objectives, and to indicate the basis on which targets might be set. Identification through objective analysis and monitoring enables cities, and citizens, to compare problems in different areas and in different years on a consistent basis. Comparison of predicted problems if nothing further is done with predictions of the impacts of possible solutions provides an immediate indication of the scale of the predicted improvement, and also highlights any possible adverse effects.

What are the weaknesses of this approach?

It is essential to start with a comprehensive list of indicators which cover all the objectives. Without this, some types of problem will be overlooked. If problems are judged analytically by reference to thresholds, there is a danger that the thresholds set will be somewhat arbitrary. It will be important to check that problems are not occurring at levels below the threshold. Where thresholds are set for different indicators, this will imply that problems of that severity are equally serious. Thus, for example: if a noise level in excess of 65dB(A) and a carbon monoxide level in excess of 8.5ppm were both to be classed as ‘slight’ problems, this would imply an equivalent severity.

The approach may only show problems as symptoms. Some analysis of the underlying causes of the problems should always be considered. For example, it would not be safe to assume that a congestion problem should be solved by adding extra capacity at the location concerned. It may be that land use patterns are encouraging longer distance travel, or that inadequate public transport is forcing people to drive. Other solutions, such as travel demand management or public transport improvements, may be more appropriate and may only be revealed by analysis of the causes of the problem.

How can we compare problems that are city-wide with those that are more serious in some areas for some people?

Problems should be classed by both severity (see above) and impact, in terms of the numbers of people affected. In the interests of equity, it will be important to consider whether a severe problem which affects few people is more or less important than a less severe problem which affects many people.

Thresholds can be used with current data, to identify the locations, times of day, and groups of traveller or resident for which problems currently occur. This level of detail is an important input to the specification of problems, but it will add to the complexity of the appraisal process (Section 13).