Regardless of what has been said so far, some road tires have a direction, even though it may not be obvious. Look at the tread and see if there is a herringbone or otherwise diagonal pattern to the tread. If so, then "arrow point" of the raised tread pattern should point in the direction of rotation. Why, you ask? Well, that works best for clearing water from the middle of the tread to the outside. If you think about it, if the point touches down first when rolling forward, as the rest of the arrow makes contact with the road, it sweeps water outward.

:)ensen.