Table 3 provides a brief representation of many of the issues surrounding the various methodologies and the ways in which they apply to each. This table is intended to provide an at-a-glance view of the issues associated with each methodology.
In the table, the following abbreviations are used: L = Low, M = Medium, H = High, a blank cell indicates “not applicable” or “nonexistent.”
Entries for Cost Category are as follows: Low Cost = <$250K, Medium Cost = $250K-$500K, and High Cost = >$500K. Assignment of methodologies to cost categories was agreed upon by expert panel members and is based on estimates only.
Entries for “Quality of Data Provided” reflect the relative level of data quality that is likely to be achieved with each study. For example, an “H” indicates a methodology is likely to provide high-quality data. A blank cell indicates that this study would not provide the type of data in question. Values for relative data quality were generated by the project team based on their understanding of the issues and upon information provided by the expert panel.
Entries for “Practical Issues” reflect the likelihood of encountering an issue which may increase the level of difficulty in performing the study. In order to have these values oriented in the same direction as the data quality values (i.e., higher is better), these values are expressed in terms of the likelihood of avoiding the issue. For these entries, the higher the value, the less complicated, and therefore more feasible, the study becomes. Values for practical issues were generated by the project team based on their understanding of the issues and upon information provided by the expert panel.
It should be noted that, while values for costs are based on specific ranges of dollar values, other values in the table are not based on specific measurable values, but on what seemed likely to the project team, based on their knowledge of this issues. For example, while there is no way to measure the likelihood that the Contemporary Case Control study will provide high quality data on injury crashes, and will very likely involve police cooperation, it seems likely that it will, based on the information provided in this report.