Ah, I thought you mean bicycle training. I always walk on the correct side like grindelwald, it wouldn't make sense to me not too; and I'm a city boy originally.
TBH I think the only cars that are /that/ quiet are electrics, and they're: a) few and far between; and b) have to have noise added artificially these days. All depends on the roads though, there's roads around here I wouldn't walk or cycle on either.
Cyclists are the same, I saw a woman and a man with two young
kids on bikes on a busy mid-sized country road recently, not only were they two abreast the first time I passed them, when I was returning it was dark
. That's just crazy like.
I think some of the comments above are a bit OTT btw. Nobody suggested that kids should cycle tens of miles to school every day, just that kids should be ejected out onto the bikes every now and then, particularly if their friends are only a couple of miles up the road.