Subject to paragraph 4, the requirements conveyed to vehicular traffic on roads by a give way sign are that no vehicle is to cross the transverse line provided for at item 3 of the sign table in Part 6 of this Schedule nearer to the major road at the side of which that line is placed, or if that line is not clearly visible, enter that major road, so as to be likely to endanger any person, or to cause the driver of another vehicle to change its speed or course in order to avoid an accident.