Botts' dots

Botts' dots

Botts' dots are round nonreflective raised pavement markers. In many U.S. states and in several other countries, Botts' dots are used (along with reflective raised pavement markers) to mark lanes on highways and arterial roads. They provide tactile feedback to drivers when they move across designated travel lanes, and are analogous to rumble strips.

Botts' dots are named after Dr. 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 also be yellow when used to substitute for the double yellow line that divides opposing directions of traffic in North America. The dots are made of various ceramic materials, or plastics like polyester.

On some roads, all lanes are marked "only" with a mix of Botts' dots and conventional reflective markers, eliminating the need to repaint lane divider lines. Along with their reflective cousins, Botts' dots are rarely used on freeways in regions where it snows, because snow plows scrape them off.


Caltrans engineers may have studied the concept of raised pavement markers as early as 1936.Stein, Mark A. "On the Button: The Quest to Perfect Botts' Dots Continues." "Los Angeles Times", 11 August 1991, sec. A, p. 3.] However, the department did not commence research in earnest until 1953, when the postwar economic boom resulted in an alarming increase in the number of cars and car accidents in California. Painted lines tended to become invisible during rain.

The initial dots were made out of glassHaldane, David. "Dots' Demise Denied." "Los Angeles Times", 7 March 1997, sec. B, p. 1.] and were attached by nails or tacks to the road, as suggested by Botts.Rubenstein, Steve. "Caltrans Plots To Erase Lots Of Botts Dots." "San Francisco Chronicle", 18 January 1997, sec. A, p. 13.] The nails were soon abandoned; his team discovered that when the dots eventually popped out under stress, the nails would puncture tires. Contrary to a common myth, the published record does not make clear whether Botts invented the famous epoxy that solved the problem; some sources indicate that one of his proteges was responsible for the epoxy.Richards, Gary. "It May Be End Of Road For Noisy Botts Dots." "Contra Costa Times", 18 January 1997, sec. A, p. 3.]

In September 1966, the California State Legislature mandated that Botts' dots were to be used for lane markings for all state highways except in areas where it snowed in the winter. Today, there are more than 25 million Botts' dots in use in California. In California, highway lanes may either be marked solely by Botts' dots, or dots placed over painted lines.

More recently, Botts' dots have been used in the snow-free areas of states other than California, most notably: Arizona, Washington, Hawaii, Louisiana, Mississippi, Nevada, and Texas. Some states that do experience snow, particularly Pennsylvania and Massachusetts use Botts' dots during the summer months for temporary lane markings in construction zones. Typically, the dots are installed when construction starts in the spring, and they are removed when work stops for the winter months.

Botts' dots are also used in the Middle East. Countries such as Saudi Arabia and the United Arab Emirates use Botts' dots in regions such as Riyadh and Abu Dhabi.

ee also

*Cat's eye
*Raised pavement marker


External links

* [ Caltrans Botts' dots fact sheet]

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Botts dots — /bots/, Slang. small, protruding, reflecting ceramic tiles used on some roads instead of painted lines to mark lanes. [after Elbert D. Botts (born 1893), U.S. chemist, who developed them] * * * …   Universalium

  • Botts dots — /bots/, Slang. small, protruding, reflecting ceramic tiles used on some roads instead of painted lines to mark lanes. [after Elbert D. Botts (born 1893), U.S. chemist, who developed them] …   Useful english dictionary

  • Elbert Dysart Botts — Dr. Elbert Dysart Botts (January 2, 1893 April 10, 1962) was the California Department of Transportation ( Caltrans ) engineer credited with overseeing the research that led to the development of Botts dots and the epoxy used to attach them to… …   Wikipedia

  • Raised pavement marker — Delineator redirects here. For the fashion magazine, see The Delineator. The amber markers separate opposing traffic lanes. The blue marker denotes a fire hydrant on the left sidewalk. A raised pavement marker is a safety device used on roads.… …   Wikipedia

  • Road surface marking — is any kind of device or material that is used on a road surface in order to convey official information. Road surface markings are used on paved roadways to provide guidance and information to drivers and pedestrians. Uniformity of the markings… …   Wikipedia

  • Road — This article is about a route, thoroughfare or way that supports travel by a means of conveyance. For a place outside a harbor where a ship can lie at anchor, see Roadstead. For public roads, see Highway. For other routes, see thoroughfare. For… …   Wikipedia

  • Road traffic safety — Sidewalks, curbs and traffic signals in Maryland, United States …   Wikipedia

  • Rumble strips — (also known as audio tactile profiled markings) are a road safety feature that alert drivers to potential danger by causing a tactile vibration and audible rumbling, transmitted through the wheels into the car body. A series of rumble strips is… …   Wikipedia

  • San José State University — Infobox University name = San José State University native name = latin name = motto = Powering Silicon Valley established = 1857 type = Public endowment = $44.2 million staff = faculty = president = Jon Whitmore students = undergrad = 21,396… …   Wikipedia

  • List of QI episodes (C series) — infobox tvseason season name = QI Series C caption = The front cover of the QI series C DVD, featuring Stephen Fry (left) and Alan Davies (right). dvd release date = 1 September 2008 country = UK network = BBC first aired = 30 September 2005 last …   Wikipedia