If the paint is turpentine based (as suggested by the fact that you managed to get most off using white spirit) you will have to make sure you get rid of
ALL of it prior to repainting. Cellulose paint will react badly with any turps based paint giving a horrible crazed/cracked surface finish. I found this out the hard way
I know hindsight etc.. is a wonderfull thing, but you said the white paint was covering your side of the road - was wondering why you didn't ride round it on the other side of the road or footpath?