McCarroll soon told her idea to the local chamber of commerce and the Riverside County Board of Supervisors, but no one listened. Finally, she took it upon herself to hand-paint a white stripe down the middle of the road. This would later help drivers since they could now easily see the actual width of the lane and keep accidents like Nurse McCarroll's from happening again. Through the Indio Women's Club and many similar women's groups, Nurse McCarroll launched a statewide letter writing campaign to tell 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. It would not be long before the idea was adopted worldwide.