Transportation authorities dictate when and how road stud lights are to be used. The basic premise, however, is that road stud lights are used where painted road markings do not provide sufficient visibility. Standard road markings may not be effective if they do not provide sufficient reflectivity in low light conditions. Since road studs are slightly above the road surface, the lenses on the studs reflect light better. This provides better visibility. Temporary road studs make an affordable option for marking lines on a newly paved asphalt road. When a new road is paved, it cannot be painted right away because the asphalt seeps into the pavement. Instead, road studs serve the same purpose as painted lines, ensuring road safety in the meantime.
COTO Standards for Road Stud Light Paving
The Commission on Transportation Operations (COTO) issued three standard specifications in August 2020 for when roadway spikes must be applied
COTO Standard Road Stud Application 1 (RSA-1): mandates the use of road studs on the centerline of heavy traffic on narrow roads. A road is considered narrow if the lane width is less than 3.5m. In addition, the contractor must place road stud lights on the yellow shoulder of one-way streets. This can only be done if the width of the paved shoulder is more than one and a half meters.
COTO Standard Road Stud Application 2 (RSA-2): specifies the use of road studs on one-way streets with low to high foot traffic. The lane width in each direction must be at least 3.5 m. RSA-2 specifies the use of road stud lights on undivided carriageway roads with two or more lanes in each direction. In addition road stud lights are required for low volume yellow shoulder lines and all-white shoulder lines (either separated or partially separated) on two-lane roads. Road stud lights are also required on all painted barrier islands and lane dividers at intersections.
COTO Standard Road Stud Application 3 (RSA-3): requires the installation of road stud lights at high-traffic driveway dividers on both divided and undivided two-lane roads.
Classification by Road Stud Light Color
According to the Department of Transportation’s regulations contractors can only use three colors of road stud light. Each color has a different meaning and is specified for use in different situations. Plastic road stud lights have both colored bodies and colored lenses, as described below:
Red Road Stud Light Indicates Prohibition: the color red usually indicates a prohibition or warns of a high security area. For example, a red road stud light in the center of a road may indicate a no overtaking line or a right hand edge line, reminding drivers not to cross a specific area.
White road studs for guidance: White is used to direct drivers to the correct route or specific driving behaviors, such as where drivers need to be instructed on how to drive or in which areas they need to enter.
According to the specification of road stud light
- Diameter: The diameter of a road stud usually affects its stability and visibility on the road. Larger diameter road studs are usually more secure and able to withstand greater vehicular pressure, and are therefore commonly used on highways or busy roads. Smaller diameter road studs may be more suitable for low-speed or low-traffic roads, or for decorative purposes as standard.
- Height; The height of a road stud affects how well it is raised on the road and how visible it is at night or in poor visibility conditions. Higher road studs are more likely to be noticed by drivers and are therefore commonly used on roads or in environments where greater visibility is required. Lower road studs may be better suited for roads that require a lower degree of protrusion, such as crosswalks or alleys.
- Material; The material of a road stud directly affects its durability and the environment in which it is used. For example, stainless steel or aluminum alloy road studs usually have a high degree of corrosion, suitable for wet or rainy areas; while galvanized steel road studs may be more suitable for use in dry environments of the road.
Conclusion
To sum up, road stud light plays an indispensable role in road traffic management, and its color classification and specification selection directly affects road safety and drivers’ driving experience. Through the rational use of red, yellow and white road studs and the selection of appropriate diameter, height and material according to different road conditions, the visibility and reflectivity of road markings can be effectively improved, thus enhancing traffic safety and facilitating traffic flow. In the future, the design and application of road stud light will continue to evolve with the advancement of technology and standards to better adapt to the ever-changing road environment and transportation needs.
