Types Of Street Signs And How They Are Made
Traffic signs communicate messages to drivers using shapes, colors, and symbols. Without traffic signs, traffic movement would be almost impossible. If you’ve ever wondered what materials are used in order to make street signs and why, we’ve compiled a brief guide on traffic sign-making essentials.
Types Of Signs
There are three types of universal traffic signs you can find on the road:
- Guide signs are signs that indicate route designations, and distances. They also show points of interest or any other cultural, recreational, or geographical information. Most guide signs are made of green, brown, or blue backgrounds with white legends. Overhead freeway and highway signs, interstate route markers, and landmark signs are just a handful of guide signs you will come across while driving.
- Regulatory signs inform road users about certain traffic laws and regulations relevant to the location. Red, white, or blue backgrounds with black, red, or white legends are common for regulatory signs which can include anything from stop signs to parking and speed limit signs.
- Warning signs are signs that warn road users of a potential hazard on the road or in a certain area where it might not be obvious. They are usually yellow with a black legend and most prominently include school signs and crosswalk signs.
The way signs are designed has changed with the advancement of technology. Professionals these days rely on modern CAD tools to create all types of guide signs, warning or regulatory signs. They can choose the right panel and add intelligent letter formatting, while simultaneously removing the human error aspect.
Which Sheeting Type is Right For A Sign?
The type of sheeting used when making a sign will have a major impact on its effectiveness. Brighter sheets are easier to recognize from a greater distance and stand out at closer distances.
When choosing the sheeting, all of the traffic safety implications of each material should be considered. A good rule of thumb for sheeting is to use engineer-grade, high-intensity prismatic, and diamond quality.:
- High-intensity prismatic sheeting can be used both in lit-up areas, as well as dark stretches of the highway, due to the superior reflection of the prismatic layer.
- Engineer-grade quality sheeting is the best choice for handicap parking signs or no parking signs.
- The main use of diamond-grade quality sheeting is the go-to sheeting for freeway and stop signs. Because of the high attention diamond grade commands, many school area signs are fluorescent yellow-green to ensure safety in the respective area.
The Raw Materials Used In Sign Manufacturing
Traffic signs are composed of three components: blank and background sheeting and a sign copy to finish off the list. The sign’s framework is made of a blank, which is usually made of aluminum, plywood, or steel.
Plywood is the most affordable blank material, but it comes at a cost. Signs made of plywood are prone to weather damage, which is why they are generally substituted with other materials. Furthermore, because plywood is porous, you must cover it with thin layers of plastic.
Aluminum is resistant to rust but must be reinforced with braces made of metal along the back. This is the most expensive option. Aluminum is more expensive than steel, but steel is more durable and doesn’t require reinforcement. You can prevent rust by applying a coating of zinc on the steel blank.
The retroreflective sheeting is used to cut background sheeting as well as the letters and symbols that will be used for the sign copy. The sheeting is made up of micro prisms or tiny glass beads embedded in flexible plastic. This allows light from the car’s headlights to reflect off the sign, and back to the driver. If the sheeting has been dyed with color, colored light will reflect off the sign. Red dye, for example, can be added to the sheeting mix when it’s in liquid form to create “STOP” signs.
Different Types Of Sign Posts
Signs are usually mounted on posts made of steel or wood. There are many lengths for signs, but the most common ones are eight, ten, and twelve feet. The purpose and the longevity of the signs come into consideration as well. For installations in areas with high winds or soft soil, longer posts are preferred.
Wood signposts you see along the roads are usually redwood or soft, treated wood and measure 4″x4″. You can easily find wood posts at every other hardware store which makes them a practical choice. However, additional steps or, rather, hassles such as drilling holes in them are required.
- Mounting holes are drilled 1 inch apart on each side of square posts. The sizes range from 1.5″ to 2.5″. Square posts are ideal for mounting signs on multiple sides and can be easily replaced if damaged.
- U-channel posts require mounting holes drilled 1 inch apart. They can be used temporarily and should not hold heavier signs.
- Tube posts are a low-cost way to mount signs. They can be used to mount signs in any direction. Mounting signs to a tube post requires additional hardware.
Street signs come in various shapes and they all serve different purposes. The same applies for the materials they are made out of, whether you need a temporary informational sign, or a highly reflective sign to warn motorists driving in harsh conditions. If you’re interested in learning more about road signs and how they are made, you can check the MUTCD site for additional information.