353. On a two-way roadway with two lanes or over, the driver of a road vehicle who is about to turn left at the intersection of a two-way roadway with two lanes or over must, after signalling his intention and ascertaining that he can do so in safety, approach the centre line of the roadway on which he is driving, proceed in a straight line to the near side of the roadway he is about to enter and turn left as soon as the way is clear so as to enter the other roadway to the right of and as close as possible to the centre line.