3. (x1;y1;z1)(x2;y2;z1)(x3;y3;z1)(x4;y4;z1)

4. (x1;y1; z1)(x2;y2;z1)(x3;y3;z1)(x4;y4;z1)

5. (x b, y b, z b ) (x2;y2;z1)(x4;y4;z1) (x а, y a, z a ) h-? (x1,y1, z1)(x3;y3;z1) h – is a safe distance. Communication center calculates real distance between the cars, using formula |х b -x a |, and compares it with h. In the case of an invalid rapprochement car, the system automatically resets the speed of the car behind.

8. (x; y; z) А В С A(x 0 ; y 0 ; z 0 ) B(x 0 ; y 0 ; z 1 ) C(x up ; y up ; z 1 )

9. (x; y; z) A BC S bc =|x up -x 1 | S ab =z 1 -z 0 t = t1=