This type of tile mainly exists in the Winter Games, though it also appear in several other tunnels. This type of tile grants increased speed to those who stepped on it, but will reduce the character's maneuverability as a cost.
They can be helpful if the level needs you to jump along large platforms and big gaps, since they can help you jump further, but not as good if the level is spiral in design, which requires good maneuverability. If you need to slow down, your best bet is of course keep jumping, but be careful so you don't accidentally jump into a hole.
There is also a Ramp variant for these tiles: Ice ramps. Bearing the same features of Ice and Ramps, this type of tile can let the character jump into air with increased speed. Though, be careful so you won't accidentally jump off the platforms, especially when in the late Winter Games levels, where mogul skiing is very common on the platforms.
They act mostly the same in Run 2.