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 of lines were painted at a cost of $163,000 (equivalent to $ in ). Later the idea was adopted worldwide.