1 / 19

Insert the title of your presentation here

Insert the title of your presentation here. Monitoring national casualty trends in Great Britain. Presented by Name Here Job Title - Date. Jeremy Broughton 16 November 2009. Contents. 1. Background. 2. Casualty forecasts for 2010. 3. Monitoring casualty trends. 4.

oswald
Download Presentation

Insert the title of your presentation here

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Insert the title of your presentation here Monitoring national casualty trends in Great Britain Presented by Name HereJob Title - Date Jeremy Broughton16 November 2009

  2. Contents 1 Background 2 Casualty forecasts for 2010 3 Monitoring casualty trends 4 GB Casualties in 2008 5 Car Secondary Safety Page 2

  3. Background Page 3 • In the late-1990s the British Government began to prepare for the next road accident casualty reduction target, the target year would be 2010 • The context for the target was provided by forecasts of the number of casualties in 2010 • The forecasts needed to take account of the effects of national policy where it could be established reliably • They should also take account of the changing volume of road travel • The presentation will describe how the forecasts were prepared • Progress towards the target has been monitored annually, which has allowed the reliability of the forecasts to be checked • The implications of the 2008 data for the forecasting procedure will be examined.

  4. Approach to casualty forecasting Page 4 The approach is based on analyses of past casualty rates per billion veh-km of traffic Previous research (in GB and other countries) had found that national casualty rates declined exponentially This model had provided useful forecasts, but needed to be improved to take account of road safety policy

  5. Casualty forecasts Page 5 • Most road safety measures affect different groups differently so the forecasts are disaggregate, with five road user groups: • car occupants • motorcyclists • pedestrians • pedal cyclists • others (mainly people travelling by bus, coach, van or lorry) • The casualty rates are adjusted to take account of the DESS measures: • Reducing Drink/Driving • Road safety Engineering • Improved Secondary Safety (crashworthiness) of cars • The adjusted rates estimate what would have happened without the DESS measures.

  6. Idealised illustration of the forecasting model Page 6

  7. An actual forecast Page 7 • This example is for car occupants KSI (Killed or Seriously Injured) • The red line is fitted to the adjusted rates from 1983 to 1998 • This is extrapolated to 2010 to forecast the rate • The forecast rate is multiplied by thevolume of car traffic forecast for 2010 to estimatethenumber of casualties • The traffic volume comes from a ‘transport scenario’

  8. The outcome Page 8 • The actual rates have been added to the previous slide for car occupants KSI • The outcome matched the forecast for the first four years • From 2003 the rate has fallen below the forecast, indicating that new policies have taken effect • These falls are independent of the benefits of improved secondary safety of modern cars (considered later) • Different patterns are found with the other road user groups

  9. Transport scenarios Page 9 • There is uncertainty about traffic growth, so a range of ‘transport scenarios’ was defined, based on official (DfT) forecasts for 2010 • Each scenario consisted of a growth prediction for each of the 5 road user groups • Implausible combinations were excluded (e.g. car use and walking would both grow strongly) • This left 36 scenarios, and a set of forecasts (KSI, slight casualties) was prepared for each

  10. New measures Page 10 • These include innovatory measures that might be taken, also substantial expansion of existing measures • The ‘Safety Targets and Accident Reduction’ Group was set up to consider the new measures that might be included in the future road safety strategy • The outcome was a list of 9 possible new measures, and the potential effectiveness of each was assessed using available evidence • The casualty forecasts depend upon which of these measures are assumed to be implemented • A review in 2007 concluded that by 2010 about 75% of the predicted benefit would have been achieved

  11. Final forecasts for 2010 • KSI and slight casualty forecasts were prepared for each of the 36 transport scenarios • Each pair of forecasts is plotted as a point on this figure (100%=no change from 1994-98 baseline) • Attention focussed on the more plausible scenarios Page 11

  12. Fatality forecasting • Trends for Killed and KSI had been very similar until 1998, so no specific target was adopted for Killed • The trends have since diverged, so attention has focused on forecasting fatalities • The same approach had proved successful Page 12

  13. Fatality forecasting: 2007 and 2008 data • The number Killed fell by 7% in 2007 and by 14% in 2008 • These sudden changes call into question the approach to casualty forecasting • Some preliminary results will be presented Page 13

  14. The casualty trends for pedestrians did not change Page 14 • There is no sign of a trend change for pedestrians in 2007 or 2008, so the pedestrian casualty forecasts are not affected. • The same is true of pedal cyclists and of motor-cyclists.

  15. …but the fatality trend for car occupants did Page 15 • The trend for serious car occupant casualties was unchanged in 2008, so the forecast is not affected • The trend for fatal car occupant casualties fell sharply in 2008, following the precedent of the previous recession in 1990 • The same is true of "Others”, the great majority of whom travel by bus, coach, van or lorry. • Why are the responses of the fatal and serious trends different?

  16. Improved Secondary Safety of cars Page 16 • Secondary safety (crashworthiness) refers to theprotection offered by a vehicle involved in an accident, whereas primary safety refers to systems such as steering and brakes which should help to avoid accidents. • Changes in secondary safety can be assessed by studying the proportion of injured car drivers who are Killed or Seriously Injured • Cars are grouped by their ‘year of first registration’. In any one year of accidents, drivers of newer cars tend to be less seriously injured • A statistical model is used to identify the effect

  17. Some results Page 17 • Separate analyses are made for Killed and seriously Injured on Built-Up (urban) and Non Built-Up (rural) roads • In each case, results show that secondary safety began to improve about the 1990 model year, and progress since then has been steady • Future benefits can be estimated, conditional upon an assumption about how much longer this progress will continue

  18. Summary results Page 18 • These detailed results can be summarised by comparing cars first registered in 2006-07 with those first registered in 1990-91 • About 2/3 fewer injured drivers of the more modern cars were killed , and about 2/5 fewer were seriously injured • A problem for the future: how to assess the benefits of advanced primary safety features such as Electronic Stability Control?

  19. Thank you Presented by Jeremy Broughton16 November 2009 Tel: 01344 770879Email: jbroughton@trl.co.uk Page 19

More Related