Do you know, many road accidents occur because drivers cannot see or read traffic signs clearly. Small or poorly sized signs make it hard for you to know rules in time. So, the selection of the right size and shape for each sign is important for safety.
We prepared this helpful and well-researched guide on road sign dimensions. You can easily understand standard size of different road signs.
Standard Road Signs Dimensions
You will see different types of traffic signs and most road signs follow set rules. These laws are set and regulated by transportation departments.
For example: the Federal Highway Administration (FHWA) decides road sign dimensions standards in the USA. Below is the list of most commonly used signs and their size.
Standard Speed Limit Sign Size
A standard speed limit sign is generally 24 inches wide and 30 inches tall. This size will provide you good visibility. Some highways and high speed roads also use large signs up to 36 inches by 48 inches.
| Speed Limit Sign Size | Width x Height in inches | Applications |
| Small | 18 x 24 | Low-speed residential streets |
| Medium | 24 x 30 | Placed at city streets & collector roads |
| Large | 30 x 36 | Use for higher-speed roads & rural routes |
| Extra Large | 36 x 48 | Highways and expressways |
Junctions Sign Size
Junction signs are mostly designed with minimum sizes of 600 × 300 mm for words. Bur, signs with arrows or the “JCT” symbol are often 525 × 375 mm. Plus, route numbers on interstate signs should be at least 600 × 600 mm for one- or two-digit routes.
For three-digit routes, you should install signs size of 750 × 600 mm. Well, common sizes include 600 × 600 mm for local roads and 900 × 900 mm or larger for highways.
Stop Sign Size
Stop signs are installed to guide you where you need to stop your vehicle completely before moving. The size of stop signs can change on the basis of the road type and country rules. In many countries like America, the minimum size is 30 inches across for stop signs.
| Road Type/Sign Features | Stop sign measurements | Dimension in cm |
| Rural roads / single-lane | 30 inches | 75 cm |
| Multi-lane and high-speed roads | 36 inches | 90 centimeter |
| Some urban areas | 24 in. | 60 cm |
| White border thickness | ¾ inches | 2 cm |
| “STOP” letter height | 10 in. | 25 centimeter |
| Installation height (rural) | 5 feet | 152 cm |
| Installation height (commercial or residential) | 7 feet | 213 cm |
Street Sign Dimensions
Street signs show you the name of roads. With the help of these signs, you can find your way easily. Its size depends on the speed of the road and the length of the street name. The most common size for a street sign is 6 inches tall and 24 inches long.
On wider roads or highways, you will notice larger signs such as 9 inches tall and 36 inches. For two-lane streets, you can install 8-inch or 9-inch signs with 6-inch letters.
Yield Sign Size
A yield sign warns you to slow down and give way to other vehicles. The standard yield sign is a triangle. Below are majorly used yield sign dimensions.
| Each side size of sign (inches) | Height (in inches) | Uses |
| 24 x 24 | Approx. 24 | Used in low-speed zones |
| 30 x 30 | 24.5 | Suitable for smaller streets and lower speeds |
| 36 x 36 | Around 29.2 | Standard size for city streets and some highways |
| 48 x 48 | 38.6 | Larger size for higher-speed or busy roads |
Roundabout Sign Dimensions
You should male sure roundabout signs have at least 600 × 600 mm size. Moreover, mini-roundabouts signs are 1 to 4 meters across. Small roundabouts signs should not be bigger than 28 meters in diameter. These sizes are useful for you to see the roundabout clearly and drive safely.
Warning Sign Dimensions
Warning signs tell you about dangers or changes on the road ahead. The most common warning signs are diamond-shaped. If we talk about its warning signs standard sizes, it mostly depends on the speed of the road and how far away drivers need to see it. Common sizes include:
| Standard Dimensions | Specific Use |
| 24 x 24 | You can use this size for low-speed roads for warnings |
| 30 x 30 | It is common size for urban and suburban locations |
| 36 x 36 | Standard size for conventional roads |
| 48 x 48 | Minimum size for freeways and expressways (high-speed or high-traffic areas) |
Guide Sign Size
A guide sign tells you where to go or gives directions. You will see them on highways, streets or city roads. On faster roads, you can use large size signs, so drivers can read them quickly. You can use smaller signs on slow streets or local roads.
| Guide Sign Type | Width (in inches) | Height (in inches) |
| General Guide Signs | 48 – 96 | 30 to 54 |
| Overhead Guide Signs | 48-180 | 30 to 118 |
| Route Marker Signs | 24 – 36 | 24 to 36 |
| Directional/Informational | 18 – 36 | 18 to 36 |
Standard Construction Sign Sizes
Standard construction sign sizes follow MUTCD guidelines to keep you safe and make signs easy to see. Common sizes are:
- The small size of the construction sign is 24 × 24 inches which is used on quiet streets near construction zones.
- A 30 × 30 inch sign is commonly used in most construction zones.
- Signs which are 36 × 36 or 48 × 48 inches are installed in busy or large construction areas. These signs provide you with high visibility.
Regulatory Sign Dimensions
Regulatory signs are traffic control devices which inform road users about traffic laws or regulations you must obey.
| Type of sign | Width | Height |
| Small regulatory signs | 24 in. | 24 inches |
| Medium regulatory signs | 24 inches | 30 – 36 in. |
| Large regulatory signs | 36 to 48 in. | 36 – 48 inches |
Road Closed Sign Dimensions
Standard “Road Closed” signs are usually 48 inches wide and 30 inches tall (48 × 30). Another common size you can use is about 41.3 inches wide and 29.5 inches tall (1050 mm × 750 mm). Well, these rectangular signs are big enough for drivers to see clearly during road closures.
Directional Signage Size
Directional signs guide you to find the way to streets, highways or important places. Following are directional sign sizes which you can use.
- 24 × 30 inches: used on small streets or local roads.
- 36 × 48 inches: You can place this size sign on city roads or moderate-speed streets.
- 48 × 60 inches: Installed on highways or multi-lane roads for better visibility.
Parking Sign Size
You can install parking signs on the road to guide drivers about parking rules. However, you should consider its size, because it affects how quickly you can read it. Below are generally used parking signs dimensions.
| Sign Type | Width (inches) | Height (inches) | Width (mm) | Height (mm) | Use |
| Standard Parking Sign | 12 | 18 | 305 | 457 | Commonly placed in most parking zones |
| Larger Parking Sign | 18 | 24 | 457 | 610 | Used for greater visibility (40 – 50 ft view distance) |
| Large Format Parking Sign | 24 | 36 | 610 | 914 | Places for high visibility in large parking lots |
Road Sign Size Chart
Shapes of Traffic Signs and Their Dimensions
There are different types of shapes available for road signs. Each shape has a meaning and follows standard sizes, so you can notice them quickly. I have prepared a below table to show you how shape impacts road sign dimensions.
| Dimensions or Shapes | Square | Disk | Triangle | Octagon | Diamond |
| Very Large | 1050 mm | 1250 mm | 1500 mm | 1200 millimeters | 1050 mm |
| Medium Large | 900 millimeters | 1050 mm | 1250 mm | 1000 mm | 900 mm |
| Normal | 700 mm | 850 mm | 1000 mm | 800 mm | 700 millimeters |
| Small | 500 mm | 650 mm | 700 mm | 600 millimeters | 500 mm |
| Extra Small | 350 millimeters | 450 mm | 500 mm | 400 mm | 350 millimeters |
Road Sign Dimensions UK
Road sign sizes in the UK follow the rules set by the Department for Transport (DfT). Because its roads, traffic rules and driving patterns are different from other countries. So, you need to consider specific laws to fit local road conditions.
- Regulatory and speed limit signs are commonly 450 mm, 600 mm, 750 mm or 900 mm in diameter.
- Warning signs typically have sizes in the range of 600 mm, 750 mm and 900 mm.
- You will find directional signs in many different sizes in the UK. Its dimensions can be over 3000 mm wide on motorways to show you clear information.
- Urban road signs generally range between 450 to 600 mm. On the other hand, rural signs are 750-900 mm and motorway signs are 1200 mm or wider.
Standard Height of Road Signs
You must place signs high enough to be visible over other vehicles, obstacles or roadside objects. You can measure the mounting height from the bottom of the sign to the road surface. For most road signs, you need to follow the standard mount height which is 1.5 meters (1500 mm) to 2.1 meters (2100 mm).
It’s important for you to place regulatory signs mounted around 2.1 to 2.8 meters high for better visibility. Remember, the exact height depends on sign type and your need for clear view to make sure driver safety.
Classification of Traffic Signs By Structure & Size
Traffic signs are made in different structures to suit their purpose and location. The design type affects how the sign is mounted, its size as well how easily you can see it while driving.
| Sign Structure | Typical Height | Tube Diameter (mm) | Tube Thickness (mm) | Cross Arm Diameter (mm) | Cross Arm Thickness (mm) |
| L-shaped Signboard | 7.5 m | 180, 219, 273 | 6 to 8 | 102, 120, 140 or 160 | 5 to 6 |
| Type F (Three F Types) | 7.5 – 8.5 m | 273, 299, 325, 377 | 8 to 12 | 140, 160 & 180 | 6 to 8 |
| Gantry Sign | 8.5 m | 325 or 377 | 10 to 12 | 120, 140, 160 or 180 | 6 to 8 |
Why Road Sign Sizes are Important For Visibility?
The size of a road sign is important because it makes you able to see and read signs clearly while driving. For example: bigger signs are easier to notice on fast or busy roads.While, smaller signs work on slow or quiet streets.
The right size makes sure you can understand the message in time, follow the rules safely, avoid accidents and take actions when required.
What Affects Road Sign Size?
The size of a road sign is not the same everywhere. It changes according to different types of road conditions and requirements.
- Road type
- Traffic speed
- Viewing distance
- Sign a message or letters
- Driver recognition level
- Location & obstacles
- Condition of light
- Information amount
- Road curvature
- Sign material & reflectivity
JACKWIN’s Advice on Choosing the Right Size Road Sign
JACKWIN is a leading supplier of road and traffic safety products. Based on our experience, you should keep the following points in mind to choose the right road sign size for safety and visibility.
- Know your road type
- Match size to traffic speed
- Consider how far drivers will see
- Check your local regulations
- Give priority to high-visibility materials
- Choose a sign that fits the area
Our Final Words
So, proper road sign sizes keep you safe and visible on the road. You should always position signs where drivers can see them early enough to react. If you are in search of the best road sign manufacturer and supplier, we are your trusted partner. Contact us today and you can get high quality road signs at affordable prices.
FAQs
Do You Need Permission To Put Up Signs?
Yes, you definitely need permission to install road signs. You can put signs if your local authorities or traffic departments approve the size, type, sign materials and location. When a sign is temporary and you want to place it on your own property, get the landowner’s consent.
How Often Should Road Signs Be Checked For Size Compliance?
You should check road signs for the correct size as it is part of regular inspections. For most areas, you can check them every 12 to 24 months. In busy or high risk places, you may need to inspect them every 6 to 12 months.
