either half main road 35 or 37 nor does either entrance road 41 or 43 with either entrance road 45 or 47 either one or more of the two one way roads or entrance roads that constitute the half main road connected with each ring shaped road embody a sloping section and an entrance road is connected with any one of the one way roads of the half main roads on either the upper or lower level which runs in the same direction as that of it in other words in relation with half main road 31 of the half main roads connected with the ring shaped road r 1 on the upper level it is to be seen that entrance road 45 emerging from the ring shaped road r 2 on the lower level in the direction of r 2 e forms a sloping section and afterwards joins half main road 31 in the r 1 e direction the same applies to the other half main roads and one way roads with necessary changes now the ways of passage of automobiles in this intersection system will be explained in fig1 imagine that a car enters the intersection by the one way road of half road 33 in the wr 1 direction upon entrance in the ring shaped road r 1 the car just proceeds along the right side if it wants to have a right turn it can just go on by entrance road 43 which it is first to come to but if it wants to go straight.