Botts' dots

Botts' dots (turtles in Washington and Oregon or buttons in Texas and other southern states) are round non-reflective plastic and ceramic raised pavement markers. In many parts of the US, Botts' dots are used, along with reflective raised pavement markers, to mark lanes on highways and arterial roads. They provide tactile and auditory feedback to drivers when moving across designated travel lanes, and are analogous to rumble strips.

Botts' dots are named after Elbert Dysart Botts, a California Department of Transportation (Caltrans) engineer credited with overseeing the research that led to the development of the markers.

Botts' dots are most commonly white but may be yellow when used to substitute for the yellow lines that divide opposing directions of traffic in North America. Many California Botts Dots are made of ceramic, other dots may be made of plastics such as polyester.

On some roads, lanes are marked only with a mix of Botts' dots and conventional reflective markers, eliminating the need to repaint lane divider lines. This kind of substitution is expressly authorized by Section 3B.14 of the Manual on Uniform Traffic Control Devices. Botts' dots and other raised markers are rarely used in regions with substantial snowfall, because snow plows damage or dislodge them.