Editing Raised pavement marker (section)

===History===
[[File:LIGHTDOME.JPG|thumb|Retroreflective spheres set into a cat's eye in the UK]]
[[Cat's eye (road)|Cat's eyes]] made out of metal were the earliest form of retroreflective pavement markers, and are in use in the [[United Kingdom]] and other parts of the world.  They were invented in the [[United Kingdom]] in 1933 by [[Percy Shaw]] and patented in 1934 (UK patents 436,290<ref>{{cite web|url=http://v3.espacenet.com/origdoc?DB=EPODOC&IDX=GB436290|title=Espacenet}}</ref> and 457,536),<ref>{{cite web|url=http://v3.espacenet.com/origdoc?DB=EPODOC&IDX=GB457536|title=Espacenet}}</ref> and the United States in 1939 (US patent 2,146,359).<ref>{{cite web|url=http://v3.espacenet.com/origdoc?DB=EPODOC&IDX=US2146359|title=Espacenet}}</ref>  On March 15, 1935, Shaw founded Reflecting Roadstuds Ltd, which became the first manufacturer of raised pavement markers.

The plastic markers now used widely throughout the United States and elsewhere appeared three decades later.  They were originally invented by American engineer [[Sidney A. Heenan]] in the course of his employment with the [[Stimsonite Corporation]] in [[Niles, Illinois]].<ref name="Heise">{{cite news |last1=Heise |first1=Kenan |title=Sidney Allen Heenan, 78, Invented Pavement Marker |work=Chicago Tribune |publisher=Tribune Publishing |date=March 23, 1997 |page=4C}} Available through [[ProQuest]] Historical Newspapers.</ref>  Heenan filed an application for a [[patent]] on October 23, 1964.  Patent No. 3,332,327 was subsequently granted on July 25, 1967.<ref>[https://patents.google.com/patent/US3332327A/ United States Patent No. 3,332,327], July 25, 1967, [[Google Patents]].</ref>

Stimsonite went on to become the leading manufacturer of retroreflective raised pavement markers in the United States<ref name="Barron">{{cite news |title=News and Views of Investments: Elastic Stop Nut to Tap Fresh Peak in Earnings |work=Barron's National Business and Financial Weekly |date=July 24, 1967 |page=22}} Available through [[ProQuest]] Central. In pertinent part, the article notes that "Stimsonite reflectors now are used on virtually all the nation's major highways" and had been already approved by the states of California and Texas. At the time this article was published, Stimsonite had been purchased by and was operating as a division of Elastic Stop Nut Corporation.</ref> and was acquired in 1999 by [[Avery Dennison Corporation]].<ref name="Avery">{{cite news |title=Avery Dennison to Purchase Stimsonite |work=Los Angeles Times |date=June 5, 1999 |page=2}} Available through [[ProQuest]] Historical Newspapers.</ref>  For six years, Avery sold Stimsonite's line under its Sun Country brand.  In 2006, Avery sold its raised pavement marker division to Ennis Paint, one of the largest manufacturers worldwide of paint for pavement markings (particularly lane markings).  After a 2020 transaction, [[PPG Industries]] now markets the Stimsonite product line under the lengthy name of "Ennis-Flint by PPG Stimsonite".  Other manufacturers of retroreflective raised pavement markers sold in the United States under various designs include [[3M]], Apex Universal, Vialume, and Ray-O-Lite.