|June Hill Robertson McCarroll|
June 30, 1867
|Died||March 30, 1954(aged 86)|
|Alma mater||Allopathic Medical College, Chicago|
|Occupation||Nurse and physician|
|Employer||Nebraska State Schools, Bureau of Indian Affairs, Southern Pacific Railroad|
|Known for||Painting the first striped lines on highways; starting the Coachella Library|
|Spouse(s)||John Robinson, d. 1914; Frank McCarroll, m. 1916|
June Hill Robertson McCarroll (June 30, 1867 – March 30, 1954) was a nurse (later a physician) with the Southern Pacific Railroad in the early 20th century who is credited by Caltrans with the simple but revolutionary idea of delineating highways with a painted line to separate lanes of traffic. The concept of painting lines to separate lanes is now in use all over the world.  According to a historic marker in Indio, California, after a near-collision in her Model T in 1917, "She personally painted the first known stripe in California on Indio Boulevard, then part of U.S. Route 99, during 1917." Her claim is disputed however.
McCarroll was born and raised in the Adirondacks. She attended a medical college in Chicago, then eventually moved to Southern California in 1904 with her first husband, John Robertson. They had hoped that the desert climate would help him recuperate from tuberculosis, but Robertson died in 1914. Within two years, she had remarried, this time to Frank McCarroll, the local station manager for the Southern Pacific Railroad. From 1907 to 1916, she was the only physician regularly practicing in the vast desert between the Salton Sea and Palm Springs. She was also the only physician serving the five Indian reservations in the area on behalf of the Bureau of Indian Affairs.
In the fall of 1917, McCarroll was driving on the road leading to her office near Indio, California, on a stretch of highway that would later be incorporated into U.S. Route 99; the highway remains today as part of Indio Boulevard. She was run off the road by a truck, as she recalled many years later:
My Model T Ford and I found ourselves face to face with a truck on the paved highway. It did not take me long to choose between a sandy berth to the right and a ten-ton truck to the left! Then I had my idea of a white line painted down the center of the highways of the country as a safety measure.
McCarroll soon communicated her idea to the local chamber of commerce and the Riverside County Board of Supervisors, with no success. Finally, she took it upon herself to hand-paint a white stripe down the middle of the road, thus establishing the actual width of the lane to prevent similar accidents. Through the Indio Women's Club and many similar women's organizations, McCarroll launched a vigorous statewide letter writing campaign on behalf of her proposal. In November 1924, the idea was adopted by the California Highway Commission and 3,500 miles of lines were painted at a cost of $163,000. Later the idea was adopted worldwide.
A memorial plaque to McCarroll is located at the intersection of Indio Boulevard and Fargo Street in Indio, California. On April 24, 2002, to honor her contribution to road safety, California officially designated the stretch of Interstate 10 near Indio east of the Indio Boulevard/Jefferson Street exit as "The Doctor June McCarroll Memorial Freeway." The plaque is located at GPS coordinates .
The Federal Highway Administration has acknowledged Kenneth I. Sawyer of the Marquette County Road Commission in Michigan for painting the first highway centerline in 1917 on what was then M-15 (part of the modern County Road 492). The first centerline was painted by Edward N. Hines in the Detroit area in 1911 on a city street, so neither can lay claim to the very first centerline in the country; for his efforts, Hines was awarded the first Paul Mijksenaar Design for Function Award in Amsterdam in 2011.
- Harris, Gloria G. & Cohen, Hannah S. (August 7, 2012). Women Trailblazers of California: Pioneers to the Present. History Press. pp. 97–99. ISBN 978-1-60949-675-3. Retrieved June 21, 2013.
- "Dr. June Robertson McCarroll, Indio, CA". Signs of History on Waymarking.com. Retrieved June 22, 2013.
- Rasmussen, Celia (October 12, 2003). "'Doc June' Drew the Line on Safety". Los Angeles Times. Retrieved June 22, 2013.
- Starr, Shannon (April 6, 2002). "Woman Credited for Highway Center Lines: Dr. June McCarroll of Indio Will Be Honored with Signs on Interstate 10". The Riverside Press-Enterprise. p. B3.
- Starr, Shannon (August 7, 2004). "She Drew the Line Toward Safer Highways: A Section of I-10 Honors Dr. June McCarroll—But Not Many Know Why". The Riverside Press-Enterprise. p. B3.
- Guzman, Richard (April 24, 2002). "Caltrans Will Honor Local Motorist Who Drew the Line". The Desert Sun. p. B1.
- Federal Highway Administration (1977). America's Highways, 1776–1976: A History of the Federal-Aid Program. Washington, DC: Government Printing Office. p. 127. OCLC 3280344.
- Boyle, Johanna (November 7, 2011). "State Inventor of Ubiquitous Centerline Honored". The Mining Journal (Marquette, MI). pp. 1A, 6A. ISSN 0898-4964. Archived from the original on April 8, 2013. Retrieved April 17, 2012.
- Laflin, Patricia B. (1998). Coachella Valley California: A Pictorial History. Virginia Beach, VA: Donning.
- "Dr. June Hill Robertson McCarroll". The 1997 Periscope. Indio, CA: Coachella Valley Historical Society.
- Patterson, Tom (March 3, 1991). "Coachella Valley medical pioneer got roads in line". The Riverside Press Enterprise.