The lowest levels of agreement were with it Improves traffic flow and makes it easier for people to meet up (each endorsed by around four in ten of those in favour of 20mph speed limits).
Y rhai yr oedd pobl yn cytuno leiaf â nhw oedd Gwella llif y traffig ac Ei gwneud hi’n haws i bobl gwrdd – (cefnogaeth gan oddeutu pedwar o bob deg o’r rhai oedd o blaid terfynau cyflymder o 20mya).