Even with the caveats about limited data and untangling causation and correlation, the statistics are striking: the first year of a scheme in Wales where the speed limit on urban roads was lowered to 20mph resulted in about 100 fewer people killed or seriously injured.
It seems obvious that a 20mph limit will be more safe in most instances.
There’s the issue with older cars having a gearing not really suited to staying at that speed (meaning revving higher and chucking out more pollution/being louder), but that’s less of an issue with new cars.
There’s also the issue of a car in 2nd gear at 20mph being ready to take off far more easily if you were to accidentally press the accelerator instead of the brake – something which often happens in traffic incidents. But again, the gearing of more recent cars is typically fine with sitting at 20mph in third gear. Car gearing seems to be designed with 20mph in mind now, as more places are enforcing it inside and outside of the UK.
And honestly, in most circumstances it won’t make a serious difference to travel time going 20 or 30. Either way you’re likely going to be stopping multiple times or stuck behind people.
Worth noting though, that the very people who collected this data say that the data can’t really be used for direct comparison and that we need at least a couple more years to see what the effect of the change is.
How old are the cars you’re thinking of that don’t like going 20mph? Do you mean they are more twitchy and will accelerate too easily even in 3rd gear?
I retired my 2003 VW last year after 15 years of service (F fallen comrade) but it couldn’t do 20mph in 3rd, only in 2nd.
For what it’s worth, I wouldn’t be in 3rd gear at 20mph in a modern turbocharged car.
For my car, 20mph is roughly 2500pm in 2nd and 1700rpm in 3rd. I don’t like to live below 2000rpm because I don’t get spooled up that low.