I've said on here before, it wouldn't necessarily bother me if they mandated speed limits, even if they were on the 'eh?!?' side for example much more 20 zones, limited to 60 on the motorway etc.
Here's the caveat however ...
I'd only be okay with it if it genuinely applied to everyone e.g. implemented electronically. What frustrates the feck out of me sometimes is when you do drive at or slightly below whatever limit, there are many who don't. So you end up with a tailgating situation or drivers getting frustrated with you. Heck this even happens if you drive a bit above the limit. And before folk start with the usual stuff about it's safe to do this depending in the circumstances/road conditions etc, all this sort of stuff also happens when it's busy, in built up areas etc.
If we all had no choice due to our vehicles being limited, they can do what the heck they like as far as I'm concerned. Too many idiots on the roads these days.