Road surface marking

There is continuous effort to improve the road marking system, and technological breakthroughs include adding retroreflectivity, increasing longevity, and lowering installation cost.

Paint is run through a series of hoses under air pressure and applied to the roadway surface along with the application of glass beads for retroreflectivity.

[13] In roads paved with setts (as in Belgian/Italian or Portuguese styles) or cobblestones, markings can be made with white blocks or stones, like marble or other light-coloured rocks.

Thermoplastic coatings are generally homogeneous dry mixes of binder resins, plasticizers, glass beads (or other optics), pigments, and fillers.

[18] Retroreflectivity occurs when incident light from vehicles is refracted within glass beads that are embedded in road markings and then reflected back into the driver's field of view.

In the United States, the demand for glass beads has led to importing from countries using outdated manufacturing regulations and techniques.

[citation needed] These techniques include the use of heavy metals such as arsenic, antimony, and lead during the manufacturing process as decolourizing and fining agents.

It has been found that the heavy metals become incorporated into the bead's glass matrix and may leach under environmental conditions that roads experience.

[citation needed] During both routine road marking removal and harsh environmental conditions, these glass beads can degrade and leach incorporated heavy metals.

One is that water vapor may have been trapped underneath the road surface markings, causing the de-bonding of asphalt binder from the aggregate materials.

[22] There are several methods of marker removal:[24] Thermoplastic road marking paint is a solid powder at room temperature.

The main auxiliary equipment includes thermoplastic paint pre-heaters, hand-push pre-markers and road marking removers.

Pavement marking manufacturers from around the world supply a variety of materials for these sites to have their products evaluated and approved for use on provincial highways.

In the United States, the first documented use of a painted center line was in 1911 along Trenton's River Road in Wayne County, Michigan.

[39] In the fall of 1917, Dr. June McCarroll of Indio, California developed the idea of white center lines and began advocating for their use, after she was run off the road by a truck while driving along a highway that would later be incorporated into US 99.

[44] The question of which color to use for highway center lines (dividing opposing traffic) in the United States was the subject of considerable debate and changing standards over a period of several decades.

[45] It was the single most controversial and most heavily debated issue resolved by the promulgation of the 1948 edition of the Manual on Uniform Traffic Control Devices (MUTCD), which mandated white as the standard color of center lines nationwide.

[45] The drafters of the 1961 MUTCD gave three reasons for the change: "(1) It contrasts with the normal white center or lane lines and thus gives emphasis to the hazard; (2) Yellow has been accepted as a symbolic warning color in signs and signals; and (3) It is consistent with the standard for no-passing-zone markings approved by the American Association of State Highway Officials and is in use in more than two-thirds of the States for barrier lines.

"[45] The 1971 edition of the MUTCD mandated yellow as the standard color of all center lines on all roads and highways in all contexts, and banned the use of white.

One odd exception was that white was still allowed as the left edge line color on the leftmost lane (closest to the median) on divided highways.

In order to maximize the longevity of zebra crossing stripes, they are usually applied to correspond with the portions of the lane on which the wheels of a car are not usually traveling, thereby reducing wear on the markings themselves.

Road markings in the Democratic People's Republic of Korea are rare, but if they do exist, the lines are usually painted white, as in the highway from Pyongyang to Nampo.

[citation needed] Many countries use yellow, orange, or red to indicate when lanes are being shifted temporarily to make room for construction projects.

In Croatia, in addition to serving as temporary signage, yellow lines are used permanently to distinguish lanes and turn directions dedicated to public transport.

Shoulder lines are generally interrupted outside built-up area to make the driver be aware the presence of crossing bicycles and pedestrians, driveways and stopping cars.

Shoulder lines on expressways and motorways are solid to imply the general absence of crossing traffic and residential driveways, as well as the disallowance of leaving the road on places other than specified exits.

[65] The markings were cautionary, and had no legal status at that time, but motorists were advised that ignoring them could weigh heavily against someone involved in an accident in their vicinity.

These devices reflect the light from a car's headlights back towards the driver in order to highlight features of the road in poor visibility or at night.

[67] Broken yellow lines at the edge of the road mean that you cannot park, but can stop for up to 5 minutes, or more if that is needed to load and unload people or cargo.

Although New Zealand follows the convention of a solid yellow line to indicate no passing on roads with two-way traffic, it uses 3 m-long (9 ft 10 in) dashed white lines with a 7 m (23 ft) gap to indicate when passing against opposing traffic is allowed on two-lane roads and shorter ones to separate lanes going in the same direction.