History of Road Stripes
Road stripes, you see them every day and night on almost every paved road you travel on. These white or yellow lines run down the center of the road and mark the edges to keep us in our own lane and safe from accidents. The question is, who first thought of putting stripes on the road, and why? History reflects two true stories that lay claim to the invention of the painted line in the center of the road.
The first account is that of Edward Hines, the chairman of the Wayne county Board of Roads in Michigan. In 1911 he was following a leaky milk truck and noticed how the creamy substance created white lines on the road. Observing this gave him the idea of painting a centerline down the middle of Wayne County roads to separate two-way traffic. His thinking was that if a line designated a lane, people would stay in theirs and accidents would be reduced. And he was right, and by the way, for his idea, Hines was inducted into the Michigan Transportation Hall of Honor in 1972.
The second account states that in 1917, Dr. June McCarroll came up with the idea of putting white lines in the center of roads as a safety measure. In fact, she painted the first line herself. Historical accounts tell us that almost being run off the road by a large truck inspired June to dedicate many years of her life to road safety for others. When she finally achieved her goal in California, other states soon followed suit. Years later, on April 24, 2002, the state of California honored June’s contributions to road safety by naming a stretch of Interstate 10 near Indio east of the Indio Boulevard and Jefferson Street exit “The Doctor June McCarroll Memorial Freeway.”
Regardless of who is credited with the inventing the road stripe, the idea quickly took off, with Michigan, Oregon and California adopting the practice of striping roads by 1924, and the country following soon thereafter. Across America, road stripes to delineate traffic were becoming the norm, and this simple invention was saving countless lives.
Meanwhile in 1918 in the United Kingdom, white road marking lines began to be used for auto safety. More specifically, the idea of painting a center white line was experimented with in Sutton Coldfield, Birmingham, when after complaints by residents over reckless driving and several collisions, the Sutton Coldfield Corporation decided to paint lines on Maney Corner as an experiment. The lines proved to be so successful in reducing accidents, that the whole country adopted it as a standard road safety device in 1926. Other countries copied the idea and soon road lines were showing up all over he world.
The Function and Use of Road Lines Expands
In the 1930s, before stop signs and traffic lights, lines were used for much more than simply telling you how much of the road was yours. Solid white lines served as road dividers, stop signs and other cautionary signals and were often manned by policemen to help direct traffic. It was during this period of time that painted lines and symbols began being viewed as more than just delineation. Automobiles were becoming more and more popular, and traveling state to state at faster speeds. To accommodate this development, an entire language was being developed using solid lines, colored lines, dotted lines, stop bars, painted arrows, legends, and more. By necessity, this language had to be consistent across the entire country. It was for this reason that during the 1930’s, the first MUTCD (Manual on Uniform Traffic Devices) was published. The MUTCD guide began developing this new language of traffic and implemented its regulations nationwide. Today the very same guide regulates every imaginable aspect of highway safety. Lines, legends, logos, arrows, reflective sheeting, signs, and so much more are regulated and made uniform across the country for the benefit of drivers and their safety. And with more regulation, came more road striping.
History of Yellow Road Lines
On April in 1917, a yellow centerline was painted across the Columbia River Highway. Deputy Peter Rexford, the sheriff of Multnomah County at that time, spearheaded this project. They decided to use yellow paint after seeing that white paint was not as visible during dark and stormy nights.
So from 1917 until 1954, both yellow and white paint was used for striping roads, with cities, counties and states constantly debating which color was more appropriate. Finally in 1954, the longstanding debate on which color to use finally ended. 47 states finally agreed to use white as the standard color for highway center lines. Oregon was the first and last state to use yellow painted lines.
Surprisingly, 17 years later, this ruling changed when the 1971 Manual on Uniform Traffic Control Devices was released. The manual announced that the use of yellow lines would be the standard for all centerlines across the nation for opposing traffic. For dividing traffic going the same direction, white would be used. The changeover took place from 1971 to 1975. Yellow made a comeback mainly because it had been established as the color for warning signs, and crossing over into opposing traffic definitely warranted a warning.
Dashed Lines
Initially, dashed lines were simply used to save money on paint. However, it was quickly found that dashed lines did more than just save dollars. They could also convey a message. In 1956, dashed lines began being used, and with them came a whole new set of rules for passing other cars on the road. These dashed lines also added more complexity to the existing language that guided traffic across America. But it was a needed addition. As double lines were being implemented across the county for two way roads, dashed lines were combined with solid lines as both a way to keep automobiles on their side of the road and to let cars know when it was or when is was not ok to pass.
Road Lines Today
Lines, Legends, Arrows and other markings, combined with raised pavement markers, are used more today than they ever have. Almost every major road in America, and most of the world, is well marked by white and yellow lines, directional arrows, interstate legends, school zone markings, stop bars, and so much more. Even bike lanes have their own set of logos and stripes, all in green. In parking lots, red designates fire lanes where cars are not allowed. Blue designates handicapped parking. Lines are everywhere, and will be a part of our lives for decades to come.
The Need for Longer Lasting Road Markings
From the very beginning, simple single part paints were used for road striping. But as automobile traffic increased around the world, the longevity of striping became an issue. In other words, painted lines were of no use when they wore off. And in high traffic areas, they wore off very quickly. This created very dangerous driving conditions for drivers who were very much dependent upon lines guiding their way. To add durability and reflectivity , glass beads by Potters Beads were often applied to lines as they dried. However, this did not improve durability nearly enough for heavy traffic. For this reason, alternative products were developed to solve this problem.
Plural Component Paints
Two part paints (epoxy) or Plural Components as they are also know, began to be used. These paints were harder and more durable than standard paint. As a reference, and to understand how tough this type of paint is, fiberglass boats are made from plural components. (Epoxy, combined with a hardener or catalyst.) These new hybrid paints, combined with glass beads, provided longer lasting stripes and pavement markings, as well as improved visibility. This type of coating is still widely used today.
Thermoplastic
A third and even more durable class of road markings are thermoplastics. This durable plastic material was originally developed during World War II as a way to deal with solvent shortages. Thermoplastics are unique in that they can be heated to form a liquid and then cooled to form a solid. This can be done repeatedly. It is easy to envision how this heating and cooling process lends itself to road striping. Apply the thermoplastic hot, let it cool, and while it’s hot, apply glass beads to increase visibility at night and add to longevity. An important feature of thermoplastics and one that makes them last so long is the thickness in which they can be applied. 125 mils is a standard thickness, which is many times that of standard paint.
On a more scientific level, thermoplastic resins are typically based on modified esters from gum or tall-oil rosins or aliphatic C5 synthetic hydrocarbons. In other words, from tree resins, or from oil. Thermoplastics in general must be heated to above 200 ºC for road application and can be sprayed on pavement or extruded as a ribbon. They solidify almost instantaneously as they cool, which makes traffic disruptions minimal, a big advantage over paints. When applied in a thickness of 1 mm, thermoplastic markings last about three years. When applied 3 mm thick, they take longer to dry after being applied, but will last for five years.
Preformed Thermoplastic
Preformed thermoplastic pavement markings (sometime called “tape”, but not to be confused with preformed polymer tape) is simply thermoplastic cut into the final shapes by the manufacturers and ready to position onto an asphalt or concrete pavement surface. This eliminates the need for metal stencils and on site melters. The ability of thermoplastic to be melted or extruded, allowed to cool, and melted again, makes Preformed Thermo possible, and very practical.
Preformed thermoplastics are put into place on the road surface and applied using a propane heat torch with a large head to spread out the heat. Some types of preformed require heating the road surface prior to the placement of the preformed thermoplastics, and others can be top heated only with no preheating of the surface. (Other than to dry it out and remove moisture) Preformed thermoplastic markings are used primarily because of their ease of application, durability and cost-effective service life. Since the plastics are melted into the surface, they are not easily damaged by snowplows. Typically, the preformed thermoplastic markings can last 3 to 6 years, and much longer in low traffic or parking lot environments. The most common applications of preformed thermoplastic pavement markings are found at intersections as transverse markings such as stop lines, legends, crosswalks, arrows, bike lane symbols, and accessibility symbols.