Cross-posted from: https://sh.itjust.works/post/20086798
During 2013–2017, casualty rates per 100 million miles were 5.16 (95% CI 4.92 to 5.42) for E- HE vehicles and 2.40 (95%CI 2.38 to 2.41) for ICE vehicles, indicating that collisions were twice as likely (RR 2.15; 95% CI 2.05 to 2.26) with E-HE vehicles. Poisson regression found no evidence that E-HE vehicles were more dangerous in rural environments (RR 0.91; 95% CI 0.74 to 1.11); but strong evidence that E-HE vehicles were three times more dangerous than ICE vehicles in urban environments (RR 2.97; 95% CI 2.41 to 3.7). Sensitivity analyses of missing data support main findings.
That doesn’t make much sense. ICE vehicles have got so quiet, especially at low speeds, that most of the noise is tyre noise.
There were far fewer models of electric and and h-ev cars being available during the time of they’ve taken their data from (7 to 11 years ago now) than ICE and even compared to how many there are now. Therefore it’s entirely possible that an issue with a particular model (for example visibility issues caused by a pillar blindspots) could skew the results.
It would be interesting to see if they can get the same results with 2019-2024 data.
What doesn’t make sense? The point that you just stated was precisely the motivation for the study — there was a concern that EVs and H-EVs are too quiet to be safely perceived by pedestrians.
In the “Strengths and weaknesses of the study” section of the paper, they touched on the age of the data being a weakness. In addition to the concern that you pointed out, there are also new regulations that have been put in place to mitigate these issues — e.g. the NHTSA mandates that cars have a minimum amount of sound that they must emit [source].
Agreed.