Upphandling av vägkvalitet: en kartläggning av kvalitetsbegreppet i väginvesteringar

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The concept of road quality is multifaceted. This report concludes that the complexity of the concept can be managed by defining it on governments transport policy of economic efficiency and long-term sustainable transport system. Then the quality concept regarding roads can be approached in the following ways:

  • • A road gives social benefits in terms of accessibility – the ability for road users to move between different locations. Lack of accessibility may occur in the form of e.g. reduced speed or a closed road. Good quality is therefore an open road that fulfils the capacity, speed, safety and comfort for which it is designed.
  • Time is an important variable for quality. All roads are of good quality when they open for traffic, but will deteriorate over time.
  • Costs constitute a reference to which all quality measures must be related. In a relative measurement for quality, efficiency is upheld when that last SEK is spent where it gives most value. For this relative measure of quality, all costs during the life of the road are relevant, whether they concern the investment itself or the subsequent maintenance.

Hence quality in roads is a complex concept, which contains all three of these aspects.

The next question is how to measure them. Three different approaches for measuring quality will be presented. The first source is customer satisfaction and accident statistics. A problem with customer surveys is that the respondents tend to focus on comfort at the expense of security issues. This because the low risk of traffic accidents makes the respondents not fully able to take in the risk aspects. Accident statistics are uncertain since it is difficult to connect the accident directly to the road quality.

A second source for quality data is the Swedish Transport Administration’s internal quality control for projects. The review of this process on a subproject in the large Förbifart Stockholm, indicates that the controls in many respects are extensive. However, the Swedish Transport Administration has implemented a reform to use more design-build contracts, that entails more self-reporting from the contractor. In a longer perspective, this risks Swedish Transport Administration’s ability for insight into the actual implementation of a road project and the measure of quality.

The third source of information on road quality refers to road surface. There is extended research into this topic on how and what to measure. This type of information should therefore be used as a basis for monitoring road network quality. The report goes on suggesting two indexes to define quality from physical aspects of the road, one for the surface and one for structure. For the surface, an index is created by weigh track depth, IRI and texture. The structural index combines, track area, crosssectional variation, edge depth and deflection. Since physical aspects of quality only is relevant to measure a few years after the road is opened for traffic, other affecting variables need to be controlled for.

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