Botts’ Dots Make Roads Safer for Motorcyclists

What are the bumps on the road called? Find out how Dr. Elbert Dysart Botts’ dots were developed to keep all drivers, including motorcyclists, safer.

Seventy years ago California’s Department of Transportation (Caltrans) recognized a growing — and deadly — problem on state highways. As the 1950s (aka the Ike Era) unfolded, a growing number of vehicles on the highways, byways, and freeways translated into a growing number of vehicular accidents, of which many involved head-on collisions when motorists accidentally drifted into an opposing lane. What to do?

The solution came by way of a Caltrans road engineer, Dr. Elbert Dysart Botts. His answer was to position small raised markers on roads’ painted center lines that originally had been tasked with keeping opposing traffic in their respective lanes. Botts’ elevated round markers (measuring several inches across and less than half an inch high) would alert errant drivers if they crossed the center line. Any vehicle traversing the raised markers would produce a rumpling sound from its tires, a noise loud and annoying enough to alert the driver. However, there were problems with the markers because they had to be tacked into place, and a vehicle’s tires easily dislodged the Dots. So Botts and his fellow engineers and scientists went back to the lab where they developed an epoxy glue sticky enough to hold the small, yet important, markers in place; the epoxy proved tough enough to withstand the pounding of a heavy vehicle’s tires.

Soon enough those raised markers became known as Botts’ Dots, a name that has stuck with them through the years. By 1965 Caltrans began using Botts’ Dots on all of California’s major roadways. Some Botts’ Dots, finished in either yellow or white, feature reflector patterns that are easy to see at night or during inclement weather. But not all dots have reflective surfaces. Plain, and less expensive, non-reflective Dots are used at less critical points of a road’s surface to help mark individual lanes as required for traffic flow.

Today there are more than 25 million Botts’ Dots dotting California’s many roads. But not all states use Botts’ Dots; similar road markers in Washington and Oregon are known as Turtles, while Texans refer to their lane-marking dots as Buttons. Many places that experience snowfall fortify their roads with sunken Botts’ Dots. By carving out a divot in the road engineers sink the Botts’ Dots to pavement level so that snow plows won’t disrupt the vital lane markers.