The present invention relates to systems and methods for marking pavement, such as asphalt used in making roads.
Pavement (asphalt) is initially black, but as it ages its color turns gray and eventually whitish gray. Concrete roads are whitish gray even when they are new. Hence, most roads are whitish gray in color.
Traffic markings are put down on roads in order to guide vehicle traffic. Such markings include lane dividers and turn arrows. A problem is that such traffic markings are typically white and yellow/orange, which has good contrast with, and visibility on, fresh black pavement, but has decreasing contrast, and decreasing visibility, as the asphalt turns whitish gray with age.
The present inventor has observed that black markings are more visible on concrete roads as well as on older pavement (whitish gray) roads. Accordingly, the present invention provides a combination of white and black markings on pavement (roads) or yellow/orange and black markings on pavement. Such markings have a higher contrast and are more visible on both black and whitish gray color pavement roads than are markings without any black color.
Markings may be provided in a combination of white and black, or of yellow/orange and black, with many variations. Any regular or irregular black color shapes may be used to provide one or more road markings.
The materials used may include, but are not limited to, the following:
An advantage of the present invention is that the markings have superior visibility on both black and whitish grey pavement.
The above mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:
Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present invention. Although the exemplification set out herein illustrates embodiments of the invention, in several forms, the embodiments disclosed below are not intended to be exhaustive or to be construed as limiting the scope of the invention to the precise forms disclosed.
The embodiments hereinafter disclosed are not intended to be exhaustive or limit the invention to the precise forms disclosed in the following description. Rather the embodiments are chosen and described so that others skilled in the art may utilize its teachings.
The steps of one embodiment of laying down a pavement marking arrangement of the invention are now described with reference to the drawings, wherein like numerals indicate like elements.
Step 1—Locate where the traffic marking is to be placed on the road. The markings may include white or yellow line segments and arrows, for example.
Step 2—Located a plurality of evenly spaced points (
Step 3—Heat solid, high density tar until the tar is liquefied (e.g., flows easily).
Step 4—Pour/apply liquid tar on point 1 until it forms a circle with radius of about one inch and thickness of about 0.03 inch, as shown in
Step 5—Place a circular, one-inch-radius rubber sheet on top of and centered on the tar at point 1 while the tar is still hot and in a liquid state, as shown in
Step 6—Pour additional hot, high density tar in liquid form on top of the rubber sheet to cover the sheet completely with a thickness of about 0.03 inch of liquid tar.
Step 7—Drop reflective elements, such as steel slag, on top of tar until the tar is saturated with the slag. The slag sinks into and merges with the tar, and comes to rest on the rubber sheet. Before application, the steel slag may be grinded into small spherical shapes of about 0.04 inch in diameter. As shown in
Step 8—Allow the assembly of
Step 9—Apply glue to the top surface of the steel slag and tar.
Step 10—Press onto the still wet glue white or yellow paper having a same size and shape as the upper layer of steel slag and tar so that the slag and tar is completely covered by the paper. The paper functions as a mask for a subsequent paint application.
Step 11—Repeat Steps 1-10 for all other points within the area to be marked.
Step 12—Paint over the area to be marked, including the paper, with white/yellow paint such that the entire area to be marked is covered with paint. The area to be marked may typically be a line segment lane divider or an arrow. The paint may have a thickness of about 0.09 inch such that the upper surface of the paint is flush with the upper surface of the top layer of tar.
In time, after Steps 1-12, the combination of weather conditions (e.g., sun, rain, heat, etc.) and pressure from the weight of vehicular traffic causes the paper to disintegrate or peel off, leaving the shiny steel slag and tar exposed and surrounded by the white/yellow painted traffic marking, as shown in
Because most of the materials used in the inventive arrangement (e.g., tar, steel slag) are the same as the material of the asphalt/pavement, the arrangement may last as long as the road itself. Thus, the arrangement has a much longer lifetime than the white/yellow markings. When the white/yellow markings need to be repainted, the tar and slag may again be covered with adhesive paper, and the entire marking may be repainted again. The paper will again disintegrate to provide sharp contrast between the black tar and the fresh white paint.
The thicknesses of the layers of tar and rubber may be correspondingly greater if the thickness of the layer of paint surrounding these layers is determined to be greater than 0.09 inch.
The steel slag may be mixed with the tar before being applied to the rubber.
While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.