Influences outside of your control
Pin-pointing exactly what change your road safety project has delivered is frequently made more complicated by the effects of other things that are going on at the same time, but which are outside of your area of influence. Examples of this may include:
- Impact of local road crashes – local residents may act safer because a recent collision in the area has increased their awareness of the risks on the road.
- Maturation of the target audience - changes in children's attitudes and behaviour may be influenced simply by the fact that as they get older, their behaviour changes anyway
- National Think! advertising campaigns
- Economic conditions and the price of fuel – this could influence the overall number of vehicles using the roads
- Weather conditions – poor weather conditions may result in changes in road user behaviour
- Initiatives by other local bodies – e.g. a step up in road-side breath tests may also influence those who have attended a workshop on drink driving
The last one may be mitigated by better joined up working locally, and trying to compliment what each other is doing rather than work in isolation.
The other issues may add 'noise' to your intervention, and make it difficult to isolate the effects of what you have done.
It is important to identify and acknowledge such influences, and in some cases it may be possible to quantify their impact on your results. If you don't acknowledge these, someone else may do so, in order to question or refute your evaluation findings!