The Road Safety Explorer used regionally; The calculation method and its assumptions. In the draft National Traffic and Transport Plan (NTTP) in 2000, the target was set that in 2010 there would be no more than 750 road deaths and 14,000 in-patients. This is respectively 30% and 25% less than in the reference year 1998. As a result of this, it was agreed that each of the nineteen regions (the Netherlands has twelve provinces) would contribute to this national target 'according to capacity' (depending on the expected population growth). In addition, each of the nineteen regions has been allotted its (provisional) target. The regions have drawn up their traffic and transport plans, necessary to reach this target, by using a software instrument that SWOV made available. This is called the Regional Road Safety Explorer, and is a method to estimate the effects of both national and regional measures. This report describes this method that the regions have used between the second half of 2001 and February 2002. The explorer calculates the regional road safety situation in prognosis year 2010 from that of the reference year 1998. It takes the following into account: - the road lengths, traffic volumes, and crash data of 1998; - the plans for sustainably safe road categorizing; - the growth in roads and traffic up to 2010; - the national and regional road safety measures (the regional ones were chosen by the regions themselves). The results, of course, depend on a good implementation and input of all this data, but also on the assumptions of the calculation method. The assumptions made are explicitly justified in this report. Based on the explorer results, all regions composed their own measure package to reach their targets. These results were calculated and are shown in a series of tables with the following data: - number of road deaths and in-patients in 1998 and target figures for 2010; - road length and traffic volumes in 1998 and 2010, with categorization and growth; - number of deaths and in-patients to be saved in 2010; - measure package per road category; - effects of infrastructural measures 1999-2010 per road category; - costs of infrastructural measures 1999-2010 per road category and road authority (in millions of guilders, price level 2000); - expected regional reduction of deaths and in-patients 1998-2010 due to both national and regional measures; - costs and benefits of infrastructural measures, expressed in terms of money; - nominal costs of infrastructural measures 2002-2010 per cost centre (in millions of guilders, price level 2000). Each region has entered its results in a report that was sent to the Ministry of Transport for assessment. We have not included these individual regional results in this report, but have totalized them for all regions together. In addition, we present the whole calculation procedure and illustrate it using data entered by SWOV for the whole country. The results for 'the Netherlands' were then compared with the totals of the nineteen regions together. The differences between these two are mainly the result of different assumptions by SWOV and the regions about the 1998 and 2010 road lengths and traffic volumes. The explorer method can be of help in drawing up regional or areal road safety plans. These are becoming increasingly important with the increase in decentralization. That is why we propose a number of improvements to the method in this report. A possible improvement is a direct link with the National Road Network Database and with a Geographical Information System (GIS). Such a linking offers possibilities of judging road safety measures at the level of a sum of road segments, intersections, and routes within specific areas. A GIS is an outstanding way of bundling different data sorts together and presenting them in the form of maps. Another possibility is to improve and better justify the various assumptions made in the calculation method of, for example, the effects of measures. In addition the calculation procedures could be adapted to allow for the differences between national and regional margins in effect and cost estimates. This makes it possible to ultimately include margins in the results of calculations.
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