Car moving without friction on a banked road How can a car move when there is no friction when it is moving on a banked road because friction makes a tire roll forward?
 A: Car going on a banked road without friction is only idealization to show certain principles of the uniform circular motion.

How can a car move when there is no friction when it is moving on a banked road

It is possible to move on a frictionless road, i.e. to maintain constant velocity assuming there is no drag. However, it is not possible to have linear acceleration as the wheel would start slipping.

because friction makes a tire roll forward?

A static friction force is needed to have rolling without slipping during acceleration, i.e. to convert from rotational to translational motion. Note that in rolling without slipping, the contact point between the ground and the wheel has velocity zero as seen from the ground!
In the absence of the static friction force (frictionless road), you can change wheel's rotational velocity, but you cannot do anything about the translational velocity. This means that the car will just keep on going at the same translational velocity, even when the wheels are locked (no rotation).

Car moving without friction on a banked road

The banked road itself, i.e. the normal force exerted by the road on the wheels, provides a force component which is horizontal and points towards center of rotation. This net force component is known as the radial force or centripetal force and enables the car to turn (change direction).
