These white hazard teeth markings are used on the approaching side of speed bumps, speed cushions and speed tables. They come in a variety of sizes to suit many situations.

How many triangle road markings you need will depend on the length and position of the raised area that you are working with. For flat-topped humps that traffic could cross from both sides, arrows should be positioned along both edges in full.

There is plenty of guidance on the proper positioning of hazard triangles in the Chapter 5 Road Traffic signs Manual - Road markings.