June Hill Robertson McCarroll -LRB- June 30, 1867 - '' March 30, 1954 -RRB- was a nurse -LRB- later a physician -RRB- with the Southern Pacific Railroad in the early twentieth century who is credited by Caltrans with the simple but revolutionary idea of delineating highways with a painted line to separate lanes of traffic.
June Hill Robertson McCarroll -LRB- June 30 1867 â '' March 30 1954 -RRB- was a nurse -LRB- later a physician -RRB- with the Southern Pacific Railroad in the early twentieth century. She has been credited by Caltrans with the idea of using a painted line to separate lanes of traffic on a highway.