period, there were a total 6,423,709 casualties. The data is disaggregated based upon three
levels of severity, which are fatalities, serious injuries, and slight injuries. Fatalities include
only those cases where death occurs in less than 30 days as a result of the accident. Serious
injuries include, for example, fractures, internal injuries, burns, concussion, and any accident
resulting in hospitalization plus those deaths that occur 30 days or more after the accident.
Slight injuries may require hospital treatment but not hospitalization and include whiplash,
slight cuts, and minor shock. Over the 20 year time series 1.5% of the accidents are classified
as fatal, 18.78% are classified as seriously injured and 79.72% are classified as slightly
injured. Table 1 shows the trends between 1979 and 1998. Total casualties have decreased
by 1.16% over this time period while total fatalities have shown a major decrease of 46.1%
and serious injuries by 40.6%. On the other hand, slight injuries have increased by 13.5%.
Data on road infrastructure includes the total road length by functional road category
(motorways, trunk roads, other roads) for each region. Motorways are controlled access
highways built to the most scrupulous and consistent design standards. Trunk roads are
generally multi-lane or intercity roads, perhaps with some controlled access but generally not.
Other roads are smaller scale roads that generally provide local access rather than inter-city
travel. This data was collected from Basic Road Statistics published by the British Road
Federation. The data was available for all regions over 20 years. Table 1 provides an
overview of the changes over time. Motorway length has increased by over 30% with other
roads showing a smaller percent increase.
Data on regional vehicle ownership was also collected from the same source.
Regional data on vehicles included number of cars currently licensed, vehicles per thousand
population, average vehicle age, percentage of vehicles first registered in the current year,
percent of households with no car, percent of households with one car and percent of