Another fun fact (hey, it’s fun to ME!~) is that the numbers on the road signs all have some kind of meaning, and once you understand the system, you’ll know what they mean, too!
Any two-digit highway sign (I-20, I-65, US-98, etc) means it’s a primary highway. If the numbers are EVEN, it’s an EAST-WEST highway. If the numbers are ODD, it’s a NORTH-SOUTH highway. So, I-20? East-West. I-95? North South. US-98? US Highway that’s East-West. Neat, huh? Watch this…
Any THREE digit highway (I-710, I-185, I-635) is EITHER a bypass, or a spur of the highway number. How do you tell the difference? Well, if the FIRST number is EVEN, it’s a bypass, meaning it will reconnect with the main highway later. If the FIRST number is ODD, it’s a spur, which means it does NOT connect back to the main highway. So, I-710? A spur (first number ODD), off of I-10. I-285? A bypass (first number EVEN), off of I-85. Neat, right? Yeah it is, you nerd…… 😛
Part of our series on road signs, Mile Markers are found on every Interstate, US highway, and State highway. You may find them on other roadways as well, usually only on access-controlled roadways.
Mile marker signs are very helpful for navigating the country, and are best used for figuring out distance from one point to another.
For the US Interstate system, Mile Markers start at 0 in the WEST or SOUTH, and INCREASE going EAST or NORTH. So if you’re traveling EAST on I-20, the mile marker numbers will be going up, but if you then turn SOUTH on I-35, the numbers will be going down. If you just remember that all miles start in San Diego (Southern California) and work their way up to Maine (Far North East USA) you’ll do fine.
A second key point to remember is that mile markers reset at every state line, no matter which direction you’re going. Heading West means the mile markers will tell you how long it is until the next state line (or end of the interstate), and the same is true if you’re headed South. Heading East or North means you’d have to know how many miles of interstate are in the state you’re in, but luckily that information is on the top of the page for each state in your Road Atlas, or readily available on google.
Alright, now that we know what they do, what can they tell us? Well, for one thing, they can give us distance to exits! Exit ramps all over the US are numbered based on the Mile section they’re in. So, exit 44 should be 44 miles from the SOUTH or WEST state line of the interstate you’re on.
Something else they can do, especially for interstate travel, is help us plan our route for long trips. When I was driving commercial trucks all over the US, I always planned for a 600 mile day, so i’d crunch the numbers to figure out where that would get me to, and then look along that route for likely delays, detours, traffic, construction, weather, or other issues.
So next time you’re on the road, take a look at those mile marker signs, and start practicing the math to figure out miles from where you are, to where you want to be!
Red: Red generally means stop. The use of red on signs is limited to stop, yield, and prohibition signs.
White: A white background indicates a regulatory sign.
Yellow: Yellow conveys a general caution message.
Green: Green shows permitted traffic movements or directional guidance.
Fluorescent yellow/green: Indicates pedestrian crossings and school zones.
Orange: Orange is used for warning and guidance in roadways work zones.
Coral: Coral is used for incident management signs.
Blue: Blue indicates road user services, tourist information, and evacuation routes.
Brown: Brown is used to show guidance to sites of public recreation or cultural interest.
Although the colors play a critical factor in providing consistency throughout the roads and highways, each shape of road signs has a specific meaning, as well. The shape of road signs can alert drivers about the message prior to reading the contents. Depending on weather conditions, the only thing you might be able to make out is the shape of the sign. If that’s the case – the shape of the sign is just as critical as the message, if not more.
The meaning of the shape of road signs
An octagon road sign conveys the need to stop. A stop sign is the only sign that uses this shape.
An upside down triangle road sign always means “yield.”
Diamond-shaped road signs always warn of possible hazards ahead. These are traffic signs, temporary traffic control signs, and some pedestrian and bicycle signs.
Pennant-shaped road signs warn drivers of no passing zones.
Round-shaped road signs are used for railroad signs. When you see a round traffic sign, you will likely see a railroad crossing or light rail transit crossing signs ahead.
A pentagon-shaped road signs provides warning that a school zone is ahead or school crossing zone is approaching.
A horizontal rectangle-shaped road signs usually provides guidance to drivers but can be used for a variety of needs.
Vertical rectangle road signs are typically used to inform drivers of regulatory notices, such as speed limits.
Interesting, isn’t it? There’s a lot of other information available in the signs all around us, and we’ll talk more about that in upcoming posts.