2 The highway/all-season tire maintains the rib-type look, but the ``ribs'' now consist of small, independent blocks positioned circumferentially around the tire, which help it deliver greater performance in dirt and rain. The zigzag sipes in the blocks also help traction on snow and ice. This type of tire is an evolutionary step up from the tire profiled above. The more aggressive tread design helps it better deal with dirt and snow, so that as loose dirt and snow are compressed into the openings, you actually end up with more traction. At the same time, the rib-type design helps the tire maintain on-road performance very close to a highway rib tire. The highway/all-season tire works well on dirt roads, gravel roads, sand, and in moderate snow.