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33 vigorous data assessments). In many cases, the materials Results and existing AMFs were related to rural two-lane roads. Expert panel members were asked to assess whether or The suburban/urban arterial expert panel reviewed research not the material was sufficient for the specification of an materials on 14 segment treatments, 19 intersection treat- AMF for an urban/suburban arterial or rural multilane ments, and 2 miscellaneous treatments. They reached consen- highway. sus on acceptable AMFs for eight of these and, after discussion, (2) If an AMF can be developed from the material pro- found three to be unnecessary for this class of roadways (see vided, what is the magnitude of the effect and to what Table 17). There were four additional AMFs that were devel- types and severities of crashes does it apply? oped by the NCHRP project research teams through further (3) Are there other studies that are not included in the analysis after the meeting. The rural multilane arterials expert existing set of materials that should be discussed at the panel reviewed material on 10 segment treatments and 7 inter- meeting? section treatments and developed AMFs for 3 of these. In ad- dition, both expert panels recommended reanalysis of the data The project team completed all logistics for the meeting, from the Elvik et al. study (74) to validate or modify the AMF the expert panel members prepared for the meeting, and the for speed change versus crash frequency change. Since neither meeting was held at the University of North Carolina (UNC) expert panel could reach consensus regarding an AMF for Highway Safety Research Center facilities. The project team median width, they also recommended an additional analysis recorded detailed notes of the ensuing discussions and con- for this treatment. Both of these efforts were described in tinually displayed both the notes and possible findings. Final Chapter 3 of this report. The details on all AMFs resulting from decisions were then made by expert panel consensus. these expert panels are presented in Chapter 5 of this report.