Streetlighting Data Tools

Figure out when streetlights are on and whether they were providing visibility during events

Nautical Twilight Schedule

Generate a yearly streetlight operating schedule for any location. Returns daily nautical dusk (lights ON) and nautical dawn (lights OFF) times.

The placeholder coordinates (36.7456, −93.4712) are the US Census population-weighted centroid for the United States, near Hartville, MO — useful for understanding average streetlight operating times across the country. For regional analysis (e.g., crashes in Kansas or the Denver metro area), use a state or metropolitan area population-weighted centroid from the same Census reference. Streetlights turn ON at −6° sun elevation (end of civil twilight) and OFF at −6° (start of civil twilight).

Phase Calculator

Upload a CSV with coordinates and timestamps. Each record gets tagged with sun elevation, twilight phase, and streetlight status.

1. Upload CSV

Drop a .csv file here or

Maximum 2.5 million rows

2. Map Columns

Confirm which columns contain your location and date/time fields.

3. Processing

4. Download Results

Download CSV

Error

GIS Service Discovery

Search across multiple public GIS servers by keyword. This crawls each server's ArcGIS REST catalog directly and live, in real time.

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Results

Safety & Lighting

Every US fatal crash with usable coordinates (NHTSA FARS, 1999–2024), run through the Phase Calculator to determine whether street lighting was providing visibility at the moment of the crash. Ask the assistant about the data, or about lighting ordinances and standards.

Street lighting providing visibilitySun providing visibility
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Ask about fatal crashes and lighting. Answers from the data state the years and filters used; answers about ordinances and standards cite their source.
How lighting is determined. For each crash the Phase Calculator computes the sun's position from the crash coordinates and local time. evStreetlightsOn is true when street lighting was providing visibility and false when the sun was. This is the only lighting determination used here; the police-reported FARS light-condition field is available in the data for reference but is not the indicator. Crashes without coordinates (all years before 1999) or with an unknown crash hour are stored but cannot be determined and do not appear on the map. Data: NHTSA FARS national files; processing by Photometrics AI.