Particularly important in precipitation, the friction forces generated in these patches determine whether a vehicle weighing a few thousand pounds moving at high speed is under control. Understanding the behavior of individual tire-tread lugs under dynamic conditions, such as acceleration, braking, and cornering, gives tire designers insight to optimize vehicle handling and responsiveness. Other considerations are ride quality, traction, wear, and low noise. The effectiveness of lug patterns on rain tires to channel away water, preventing hydro-planing, or on snow tires to grip, are also important. Tread lugs require intimate contact with the ground.
Improper contact degrades traction and increases wear.
As a tire is driven over a viewing window, the camera captures digital images of rolling tire footprints during vehicle operation. The FlashCam provides a combination of speed and light sensitivity not available before. Standard CCD cameras cannot provide the extremely short shutter speeds and still have sensitivity to image the footprint under reasonable lighting conditions. Now they're into the thousands. Also, the short shutter speed can be utilized to produce multiple exposures on a single video readout frame.