When interstate signs are installed, there is more to mounting than just the message. The type of sign, location, shape, and angle are all factors that can affect how the sign is mounted. Whether or not the area is urban or rural, a work zone or a cultural area, the speed of the drivers, the way weather affects the roads—all of these things are also considerations. Rather than restate over 1,000 pages of the MUTCD guide, we went through and found some interesting facts about what all is meticulously dictated when it comes to mounting signage.
Regulatory signs are the signs that communicate the regulations, or rules of the road. These signs include “stop,” “yield,” and “do not enter” signs. If a regulatory sign is missing or damaged, they should be replaced or repaired within hours. The Federal Highway Administration says that if a sign is ever being replaced or repaired, for the sign technician to not assume that the previous sign was placed correctly. For urban areas, there are more standardized rules. For rural areas, unfamiliar drivers are taken into consideration and this affects sign placement. These are the most important signs to replace and have installed properly. If there are any mistakes or they’re completely absent, traffic accidents can occur. For regulatory signs, their prompt installation is as important as accuracy. Here is an image from the USDOT showing the specifics of mounting regulatory signs.
Sign shape is also affects how the sign is mounted. Signs that are different shapes are required to be on separate posts: if a stop sign is a hexagon and a yield sign is a triangle, there will never be a yield and a stop sign mounted on the same post back-to-back—even if the road does have a stop on one side and a yield on the other. The shapes must line up back to back so that they don’t ever protrude past the edges of the sign on the other side. The manual also offers suggestions, such as changing the sizes of signs so that no edge protrudes or increasing the height of the sign so that the “back mounted” sign can line up with the bottom edge of the sign on top. This might seem a little confusing, but these regulations are in place in order to provide the most clarity for the viewer while avoiding any visual distraction from the main message of the sign and everything has been decided after extensive studies regarding what best conveys the message.
Word messages are another facet of signage that is heavily monitored. Any signs with word messages must be left to right and aligned horizontally (unless otherwise specified). All lettering follows the standard alphabet in what’s called the “Standard Highway Signs” publication. Names, places, and highways are required to use a mix of capital and lower case lettering. The size is determined using a ratio: one inch of letter height for every thirty feet of legible distance. This is why signs have to be so large—the letters end up being several feet tall on major interstates for maximum legibility! Since word messages are required to use as little punctuation as possible, other methods are used to show that a word is an abbreviation. For example, U.S. (for United States) would instead be written as U S: two capital letters and a space in-between, with the space being between 1/2 and 3/4 of the letter height of the initials.
Finally, what about symbols on interstate signage? These are also required to be either similar or exact to the ones in the Standard Highway Signs. Most of these need to be oriented to the left but might be mirrored if it more accurately conveys its message. If a sign is in the process of changing from a word message sign to a symbol, it will be accompanied by an educational plaque until the users have assimilated to the transition. These plaques may also stay mounted as long as they’re in good condition, even if drivers successfully know the meaning of the symbol and the plaque is no longer needed.
Another interesting tidbit is that cultural or recreational symbols are not allowed on any streets or highways outside of that area. Those symbols also cannot be on any regulatory or warning sign. Since the priority for regulatory signs and warning signs is to convey their messages without distraction, you might instead see a clump of signs iterating all of these messages separately, using colors to draw your eye to the most pressing message.
When it comes to the wording, lettering, characters, etc., we are very familiar with how specific state signage has to be. Since we make these signs, we make sure all of these regulations are met in tandem with the state department of transportation placing the order. The average person might never realize all of the tiny details that go into making the signs they pass every day on the way to work, home, or school. If you’ve ever wondered how do we make sure every sign follows the same rules, how do we make sure it’s mounted where it can be seen by everyone at a distance, how do we manage signs around curves or temporary conditions like construction zones or work areas, don’t worry. The MUTCD has considered and studied every circumstance and constantly updates their guide to make sure our transportation signage is understood and streamlined.
We know this because we’re Interstate Signways, and we constantly refer to this guide to make sure the signs we make adhere to all of your state’s requirements. You can trust we have your safety in mind and are doing the most to mark the way with our interstate signs, error-free and efficiently!