A Coruroy road or log road is a type of road made by placing sand-covered logs perpendicular to the direction of the road over a low or swampy area. The result is an improvement over impassable mud or dirt roads, yet is a bumpy ride in the best of conditions and a hazard to horses due to loose logs that can roll and shift. This type of road was already constructed in Roman times. It is known to have been used as early as 4,000 BC with examples found in Glastonbury, England . Compare the puncheon or plank road, which uses hewn boards instead of logs, resulting in a smoother and safer surface.