To classify intersections as part of a modal HII, modal scores were analyzed to determine a threshold (or cut-off) value. There is no fixed formula for setting these cut-off scores; rather, they were determined through a blend of data analysis and professional judgment. The goal was to identify intersections that account for a meaningful share of serious injury and fatal crashes without capturing too many locations, which would dilute the results. This process was conducted separately for each mode. The final HII includes any intersection that met the cut-off for at least one mode. The table below summarizes the cut-off scores, the number of intersections identified, and the proportion of crashes those intersections represent
Table 3. HII by mode and their associated crashes
Mode
Cut-off
Intersections
Crashes included
Total
Percentage
Total
Percentage
All
K/A
All
K/A
Pedestrian
3
110
0.49%
194
94
48.38%
100%
Bicyclist
3
30
0.13%
33
28
20.25%
100%
Motorcyclist
3
124
0.55%
154
124
36.49%
100%
Motor vehicle
20
105
0.47%
4,732
156
18.83%
20.86%
CMV
3
38
0.17%
194
23
13.91%
100%
Overall * 55.61% * Note: Overall values are not the sum of modal values. Intersections may appear on multiple modal HIIs, and individual crashes may involve multiple modes or be counted under different intersection classifications. N/A 347 1.54% 7,320 416 29.12%
In addition to scoring intersections based on crash history, each intersection was evaluated for its relationship to the modal High Injury Networks (HINs). Intersections were flagged if they fell along an HIN segment for a given mode. For details on HIN development, refer to Appendix B - State of Safety Report . It is important to note that an intersection’s crash score or rank does not need to correlate directly with its presence on the HIN. For instance, a corridor may appear on the HIN due to high non-intersection crash volumes, even if the intersections themselves are not high-ranked. Nonetheless, such intersections remain critical for consideration in safety planning due to their network context.
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