| 摘要 |
A portable apparatus for warning drivers of temporary and/or hazardous road conditions ahead is provided herein. It includes a portable flat mat of resilient material which is either removably or permanently secured to the road surface in or near the path of an oncoming vehicle. The mat has a plurality of rectangular, equidistantly spaced depressions formed in the upper surface of the mat, each depression having a specified configuration. When at least some of the wheels of a multi-wheeled vehicle transverses the depressions, an audible and vibrational warning is given to the driver of the multi-wheeled vehicle of a road condition ahead which requires special attention. |
