How Are Pavement Markings Used & Removed?

Pavement Markings

Pavement markings provide drivers critical guidance and information when traveling our highways and roadways. In some cases they are used along side other signs and devices to assist drivers, and in other cases they are used alone.

Pavement markings also improve safety. For example, centerlines have been shown to cut accident frequency by over 29%, compared to roads without them. But they do have their limitations, like when they are covered by snow and hard to see.

Despite their limitations, pavement markings have a unique

Advantage, in that they can convey important information to

a driver without diverting their attention from the road

What materials are used for pavement markings?

Many different types of materials are used, and the choice depends on cost, durability, retro-reflectivity, pavement surface, and drying time.

Some of the most common materials include:

Paint

Water-based paint applied either cold or hot is the most commonly used pavement marking. It is low cost with a short drying time, but its visibility on wet nights is just moderate. Traffic and snow plowing wear it away in about a year. Oil-based paint, when used must meet environmental air quality regulations.

Thermoplastics

These pavement marketing materials are made of thermoplastic heated to about 400° F and spread onto the pavement surface. Glass beads–to increase reflections–can be spread on top, mixed in, or both. Thermoplastics have a long service life, good visibility, and good retroreflectivity. The no-track time is short, and the cost is medium-range. Special application equipment is required.

Epoxy

Also applied as a liquid with special equipment, epoxy has good visibility and retroreflectivity, and the cost is moderate. Not track time is 5-20 minutes. Markings last about three to four years.

Tapes

Pre-formed tape can either be inlaid as part of new construction, or overlaid. It has excellent visibility and retroreflectivity and lasts 7-8 years, but is higher cost. Wet reflective tape has excellent wet night retroreflectivity with about a 4-year life. Cost is medium, and durability is poor. Modifications are being made to produce a tape with both durability and wet night retroreflective qualities.

Most Cost Effective Marking Material

Conventional paints are the most cost effective, especially for low-volume roads. In higher traffic areas, where conventional paints must be renewed in less than one year, thermoplastics or other durable marketing products may be more economical. Using them also reduces the frequency of travel delays and hazards of construction zones during application.

Whichever material you us, it should remain the correct color and adequately reflectorized throughout its useful life.

Markings for Night Use

Markings that need to be visible at night must be retroreflective. In general this applies to all pavement markings except parking lines and curb markings. For painting, glass beads are mixed in or dropped on the markings while still wet.

Durable products are made with reflecting materials. In pedestrian areas, marking materials should not create slipping or tripping hazards. Raised pavement markets can be useful to supplement pavement marking, but cost is a factor, and they must be correctly installed. Wet reflective tape is another supplement option.

Pavement Markings can be used for a variety of reasons, including:

No passing zones
Center lines
Lane lines
Edge lines
Channelizing lines
Railroad Crossing
Crosswalks and Stop Lines
Delineators
Words and Symbols

Color – Pavement markings must be yellow or white, red and blue are used in special cases.

Yellow longitudinal lines separate traffic flowing in opposite directions, or mark the left edge of the pavement on one-way roads.
White longitudinal lines separate traffic flowing in the same direction, or mark the right edge of the pavement.
Contrasting black markings placed next to a white marking may be used to make the white line stand out on light-colored pavements.
Words and symbols, crosswalk and stop lines are white.
Red and blue are used in special cases. Blue is for parking spaces for persons with disabilities; red is for raised pavement markings, such as one-way streets or alleys.

Width

Line width indicates the degree of emphasis. Normal centerlines and edge lines are 4” – 6” wide. A wide line is at least twice the width of a normal line.

Number

Double lines—two normal width lines separated by a discernible space—indicate maximum restriction: driving across them is prohibited.

Solid vs. Broken

Solid lines discourage crossing and should not be crossed. Broken lines may be crossed. Broken lines are formed of segments and gaps, usually in the ratio of 1:3. For example, a rural road may have a 10ft segment, followed by a 30ft gap.

Center Lines

A center line separates traffic traveling in opposite directions and is usually at the geometrical center of the pavement. Centerlines give drivers important guidance and can significantly enhance safety.

No-Passing Zones

A no-passing zone at hills and curves shall be used where the sight distance is less than the minimum necessary for safe passing at the prevailing or posted speed based on a documented engineering study.

Lanelines

Broken lines, called lanelines, separate lanes of traffic in the same direction. They are usually a normal broken white line which permits lane changing. Use a normal solid white line as the lane line in critical areas where you wish to discourage lane changing, such as an approach to a busy intersection.Wide solid lane markings may be used for greater emphasis.

Edgelines

Pavement edgeline markings give drivers a guide to the edge of the pavement and also enhance safety. Edge Lines are a particularly valuable visual reference during bad weather and poor visibility, especially along curves. Wide solid edge line markings may be used for greater emphasis.

Channelizing lines

Channelizing lines can be used to form channelizing islands where traffic is going in the same direction on either side of the island. They shall be a wide or double wide solid white line.

Stop lines

Stop lines are solid white lines and should be 12-24 inches wide. Stop lines emphasize the stop condition and indicate where vehicles must stop.

Railroad crossings

Special pavement markings are required before railroad crossing switch signals or automatic gates and at all crossings where the prevailing speed of highway traffic is 40 mph or higher.

Words and symbols

Word and symbol markings may guide, warn or regulate traffic. They should not have more than three lines of information and most not be used where a movement that would otherwise be legal is prohibited, unless they accompany standard signs. Letters or numerals should b 6’ or more in height.

The Manual on Uniform Traffic Control Devices with the Minnesota supplement are used as the state standards. Using these will ensure statewide consistency in signing and markings.

Click here to download this manual for free.

Pavement Marking Removal

There are several types of pavement marking removal, including sand-blasting, soda-blasting, shot-blasting and gas torching. The two most used techniques are Waterblasting and Grinding.

Grinding

Scarring of the Pavement Surface: Grinding will always create some measure of scarring. The amount of scarring will be determined by the precision of the equipment being used and the skill of the operator. However, in order for a grinder to remove marking material imbedded in the recesses of asphalt, scarring will occur. In freezing temperatures rain, snow and ice can collect in these scarred areas and create unforeseen hazards.

Environmentally Hazardous: The by-product of the grinding process is basically marking and asphalt residue. Most often, this residue is left on the road to be blown away by the wind or washed away by the rain. If there is any clean-up of the grinding residue, it is typically a secondary process provided by either a mechanical broom or a vacuum truck.

Grinding cannot remove temporary tape: Grinders are not able to effectively remove and dispose of temporary tape markings.

Waterblasting

The needle-sharp water jets of a properly designed water blasting system will reach like tiny fingers into the pores of the asphalt with remarkable effectiveness. While a small measure of the asphalt fines make break away, the surface plain of the asphalt remains unscarred. When driving over an area where a road marking was removed effectively by water blasting, you will not feel any change in the surface of the pavement.

Environmentally Friendly

With properly designed captive water blasting, the needle-sharp water jets pulverize the marking–reducing it to fine particles. At 40,000 psi, the chaos created within the captive environment enhances the effectiveness of the vacuum recovery. The result is precision removal and a very clean, nearly dry surface.

Removes Temporary Tape

The needle sharp water jets pulverize temporary tape, and the simultaneous vacuum recovery removes it from the surface.

Waterblasting offers a complete removal of all forms of durable traffic markings from all surfaces and is quick, clean and cost efficient. Best of all, very little to no confusing mark left behind, NO re-surfacing, and NO secondary clean-up or drying is necessary. Thermoplastic, waterborne paints, epoxy paints, rubberized paints, and even temporary and permanent foil-backed marks are easily removed.

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