When using multiple CMF values, what is a key consideration?

When utilizing multiple Crash Modification Factors (CMFs), a critical consideration is that treatments should be independent to avoid double dipping. This principle is essential because when applying multiple treatments to address roadway safety, it's important that the effectiveness of each treatment is assessed on its own merits without the influence of overlapping effects from other treatments.

If treatments are not independent, there is a risk of double counting the safety benefits, which can result in inflated effectiveness and misleading conclusions about safety improvements. By ensuring that each treatment can be evaluated separately, it allows for accurate assessments of how well each individual intervention works, leading to better decision-making in road safety strategies.

Other considerations, while important in different contexts, do not capture this core principle. For instance, while ensuring the same treatment type can have some effect on consistency, it does not inherently address the risk of overlap in treatment effectiveness. Executing treatments in sequence may be necessary for certain interventions, but it does not inherently guarantee that the effects will be independent. Using averages from CMFs could dilute the specific impacts of individual treatments, which could lead to less effective or confusing outcomes. Thus, focusing on the independence of treatments is crucial for valid analysis and implementation in road safety improvements.