For cars, with very rare exceptions, the radius of rotation is 7.50 m. Buses and trucks require large rotation radii, as a result of which in most cases it is recommended not to use the radii of the sides less – 9 m. If the intersection has a crew parking, the excessive radius, as a rule, constrains the size of the sidewalk, as a result of which it is recommended to resort to roundings with smaller radii.
It is very desirable to design radii of turns to conduct depending on the permissible speed of the crews on the intersection streets. For example, if the speed of the transport of 30 km /h suitable for the intersection, and the radius allows a speed of 18 km /h, then the traffic at the intersection would delay the main traffic on the street. In the presence of a clearly expressed intensive movement on the street, at the intersection of it with a secondary street, a special planning reception may be applied. A segment of the green strip of intensive traffic, located against an intersecting street, plays the role of the central island, around which the ring movement occurs. The crews entering the intensive traffic from an intersecting street are folded right, move along with a stream of soon traffic along the intensive traffic to the right, if they need to go in this direction. If you need to go in the opposite direction, then they intersect the flows of automobile speed and envelop the green strip along the semicircle and pour into the flow of the soon movement walking along the street of intense traffic in the opposite direction. All this can be decorated without special alarm and regulation by the movement of the police forces. The need to give green islands a sufficient radius, providing the main turn of the pouring crews, forces to provide for green stripes in the middle of the street width, providing a radius of rotation. It is practically established that the width of the island should not be less than 12 m. With a smaller width of the island, cars enveloping it in the adjacent lane, which threatens with a clash.
