cross-posted from: https://lemm.ee/post/38852281
Figures published by the Welsh Government show casualty reductions as follows for the period January to March 2024, in comparison with January to March 2023:
All severities at all speeds: 811 (2024); 4348 (2023);
20mph. All severities: 300 (2024); 662 (2023)
Killed or seriously injured: 63 (2024); 144 (2023)
Slightly injured: 237 (2024); 518 (2023)
30mph. All severities: 77 (2024); 1522 (2023)
Killed or seriously injured: 15 (2024); 343 (2023)
Slightly injured: 62 (2024); 1179 (2023)
40mph. All severities: 74 (2024); 397 (2023)
Killed or seriously injured: 20 (2024); 98 (2023)
Slightly injured: 54 (2024); 299 (2023)
50mph. All severities: 94 (2024); 273 (2023)
Killed or seriously injured: 23 (2024); 67 (2023)
Slightly injured: 71(2024); 206 (2023)
60mph. All severities: 214 (2024); 1235 (2023)
Killed or seriously injured: 71 (2024); 401 (2023)
Slightly injured: 143 (2024); 834 (2023)
70mph. All severities: 52 (2024); 259 (2023)
Killed or seriously injured: 12 (2024); 73 (2023)
Slightly injured: 40 (2024); 186 (2023)
Or, to put it another way, a faster speed limit means drivers get to the next traffic jam faster, making it larger more quickly.
Traffic is a flow problem, what you are saying makes no sense. I dont think I will change your mind so we should end this discussion here.
Traffic flows best at 20mph. Here’s a scientific study that proves it (pdf warning)
Somehow, I don’t think you will change his mind, ironically enough.