Roadway safety data can show a reported pattern across time and place, but it does not reconstruct a motorcycle crash or establish fault. A map or chart is most useful when its geography, date range, filters, and limits are kept with the observation.

Read the map settings first

A safety-data map can display a selected area and reporting period. Before comparing locations, note the road, intersection, direction of travel, time range, crash type, and any filter selected. A map view may change when a user zooms, changes a layer, or chooses a different date range.

  • The exact road segment or intersection selected
  • The beginning and end dates used by the display
  • Any crash-type, severity, or location filter
  • Whether the display reports counts, locations, or another selected measure
  • The date the map was accessed and the agency that provides it

Compare the same measure and period

NCDOT’s directory distinguishes crash-location maps, intersection crash frequency and section safety scores. Its motorcycle map covers the most recent five years, while other maps use different periods. Check the dates shown in the selected map rather than assuming every display covers the same years.

A crash count is not a crash rate. Before comparing two roads, identify whether the display uses a count, a rate or a score, and keep the measure’s definition with your notes. A larger count alone does not show the risk per trip or mile. If the needed traffic-exposure information is unavailable, leave that comparison unresolved.

NCDOT describes its summarized intersection and road-section data as planning information, rather than detailed project analysis. Save the selected layer, filters, access date and agency explanation with the map so that another reader can understand the comparison.

What a pattern can and cannot show

A cluster or count can provide broader location context. It does not identify the sequence of one collision, confirm a vehicle’s path, or decide whether a particular condition contributed to that event. Roadway configuration, construction, traffic controls, weather, and reporting practices may also change over time.

The North Carolina Department of Transportation provides Safety Data Maps for broader safety information. Keep a map separate from crash reports, photographs, video, and firsthand accounts rather than treating all of them as interchangeable.

A useful question is: what does this agency display for this roadway and period? That is different from asking what caused a crash. Questions about a North Carolina motorcycle-accident claim require a fact-specific review.

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