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Story history
Score and comment observations over time
How do Traffic Signals Work (2019)
HN #49,789,081 | submitted 2026-09-21 16:06 UTC | practical.engineering
40 observationsby at1as
32 points
Latest score
21 comments
Latest comments
+31
Score change
Rank history is not tracked yet in the current dataset, so this first slice focuses on score and comment movement.
Score
Range 1 to 32
2026-09-21 16:12 UTC2026-09-21 19:20 UTC
Comments
Range 0 to 21
2026-09-21 16:12 UTC2026-09-21 19:20 UTC
Observation history
Observation times are irregular and reflect when the tracker refreshed this story.
First 2026-09-21 16:12 UTCLatest 2026-09-21 19:20 UTC
| Observed at | Score | Comments | Rank |
|---|---|---|---|
| 2026-09-21 19:20 UTC | 32 | 21 | not tracked |
| 2026-09-21 19:15 UTC | 31 | 21 | not tracked |
| 2026-09-21 19:11 UTC | 30 | 21 | not tracked |
| 2026-09-21 19:06 UTC | 29 | 20 | not tracked |
| 2026-09-21 19:01 UTC | 29 | 18 | not tracked |
| 2026-09-21 18:57 UTC | 26 | 18 | not tracked |
| 2026-09-21 18:52 UTC | 26 | 17 | not tracked |
| 2026-09-21 18:47 UTC | 26 | 17 | not tracked |
| 2026-09-21 18:43 UTC | 26 | 17 | not tracked |
| 2026-09-21 18:38 UTC | 25 | 17 | not tracked |
| 2026-09-21 18:33 UTC | 23 | 17 | not tracked |
| 2026-09-21 18:28 UTC | 21 | 16 | not tracked |
| 2026-09-21 18:24 UTC | 21 | 16 | not tracked |
| 2026-09-21 18:17 UTC | 21 | 16 | not tracked |
| 2026-09-21 18:13 UTC | 21 | 16 | not tracked |
| 2026-09-21 18:08 UTC | 20 | 14 | not tracked |
| 2026-09-21 18:03 UTC | 18 | 11 | not tracked |
| 2026-09-21 17:58 UTC | 16 | 11 | not tracked |
| 2026-09-21 17:54 UTC | 14 | 11 | not tracked |
| 2026-09-21 17:49 UTC | 12 | 8 | not tracked |
| 2026-09-21 17:44 UTC | 9 | 8 | not tracked |
| 2026-09-21 17:40 UTC | 9 | 6 | not tracked |
| 2026-09-21 17:35 UTC | 9 | 5 | not tracked |
| 2026-09-21 17:30 UTC | 9 | 5 | not tracked |
| 2026-09-21 17:26 UTC | 8 | 5 | not tracked |
| 2026-09-21 17:21 UTC | 8 | 4 | not tracked |
| 2026-09-21 17:15 UTC | 7 | 4 | not tracked |
| 2026-09-21 17:10 UTC | 7 | 3 | not tracked |
| 2026-09-21 17:05 UTC | 6 | 3 | not tracked |
| 2026-09-21 17:01 UTC | 6 | 2 | not tracked |
| 2026-09-21 16:56 UTC | 5 | 2 | not tracked |
| 2026-09-21 16:51 UTC | 5 | 1 | not tracked |
| 2026-09-21 16:46 UTC | 4 | 1 | not tracked |
| 2026-09-21 16:42 UTC | 4 | 1 | not tracked |
| 2026-09-21 16:37 UTC | 3 | 0 | not tracked |
| 2026-09-21 16:32 UTC | 3 | 0 | not tracked |
| 2026-09-21 16:28 UTC | 3 | 0 | not tracked |
| 2026-09-21 16:23 UTC | 2 | 0 | not tracked |
| 2026-09-21 16:18 UTC | 2 | 0 | not tracked |
| 2026-09-21 16:12 UTC | 1 | 0 | not tracked |