why are highway sections slanted here's what you need to know!

25/04/2023    By: taewoo limited

Have you ever wondered why highways are slanted? You're not alone! All over the world, countless people have asked this same question. The answer is actually quite fascinating.

Highway roads are slanted for a variety of reasons, with some of the most common being safety considerations and drainage control. In this article, we'll explore five different reasons why highway roads are slanted. From surface drainage to roadbed strength, the explanations may surprise you.

So let's get started! Read on to discover five of the most common explanations for why highway roads are slanted. Be sure to take notes so that you can learn more about how roads work and why they look the way they do!

  • Prevent Water Accumulation

If you've ever driven on a highway in the rain, you may have noticed that the roads have an angle to them. The slant isn't just a design choice—it actually serves a very important purpose.

The primary reason why highways are slanted is to prevent water accumulation. When roads are built, they are typically tilted slightly away from the center so any rain or snowmelt will slide off and not accumulate into puddles or pools. This not only keeps water out of the way of traffic but also helps to protect the pavement from ice and damage due to standing water.

In addition, slanting roads towards the sides also helps divert surface runoff away from highways and towards drainage systems, creating less runoff pollution in nearby waterways. By implementing this design feature, road construction teams can ensure that highways remain safe and dry all year round, benefiting both cars and the environment!

  • Increase Driver Visibility

One of the main reasons why highway roads are slanted is to increase driver visibility. When the roads are built on an incline, they allow drivers a better view of what lies ahead. This is especially important if you're driving long distances, as it can help prevent accidents caused by drivers not being able to see further down the road.

The angle of the slant also plays a part in increasing driver visibility. With a higher angle, you get an even greater range of vision because the ground is farther away from your eyes. So if you were driving down a typical straight highway, your view would be limited to whatever was within your immediate vicinity—but on a slanted highway, you can see farther out into the distance.

This extra visibility helps reduce accidents and makes for safer highways overall. So even though it may be more complicated and expensive to build highways with inclines, it's well worth it for reasons such as increased safety and better driver visibility.

  • Enhance Drainage Conditions

Another great (and often overlooked) benefit of the slanted highway is that it helps ensure drainage conditions are suitable and safe for drivers. So why is drainage important? Well, when rainwater accumulates on the road, it could cause visibility issues, and, more dangerously, slippery driving conditions.

The slant of the highway enables rainwater to quickly run off to the sides, instead of settling in the middle and causing poor visibility or unsafe driving conditions. Plus, these highways usually have extra drainage systems like gutters and wider shoulders to help capture and carry away excess water.

Curves Count Too

Highways also feature slight curves, which aren’t just there for esthetic purposes—they too form part of an effective drainage system. These curves help decrease the height difference between sections of the highway, which helps capture more runoff water from higher sections that it can then safely carry away without creating any kind of danger for drivers.

Overall, when you take all these factors into consideration—the slope angle, proper drainage systems, and even those gentle curves—you can see how they all come together to make highways safer by enhancing drainage conditions.

  • Improve Road Grip and Stability

One of the main reasons why highways are slanted is to drastically improve the performance of tires and increase road grip and stability. That's why you'll often find that highways take a straight line with a gentle slope to the side so that when the cars are driving along, there is an angle allowing for improved traction.

This increased road grip not only helps cars stay firmly on the roads but also helps in hazardous conditions, like when it's raining or snowing. Drivers can be confident that their tires will remain firmly on the ground instead of sliding all over.

The angle also helps with drainage. When it rains heavily, instead of puddles forming all over the roads and making it difficult to drive safely, water is directed away from the middle of the road and out towards the sides. This prevents flooding and allows for easier navigation during wet weather.

Plus, this slope also helps with maintenance by putting less strain on vehicles and providing a smoother ride—making long drives much more comfortable!

  • Reduce Accidents by Facilitating Better Drainage

The fifth reason why highways are slanted is that it helps reduce accidents by facilitating better drainage. You see, when water gets on the road, it can be very dangerous for drivers who aren't aware of its presence. However, the slight incline of highway roads ensures that the water can drain away from the driving lane faster, reducing the risk of slipping and skidding caused by slippery roads.

In addition, this slight tilt also helps to reduce the pooling of water in certain areas. When cars drive through these puddles at high speed, there is a risk of aquaplaning, which can cause an accident. Having a slanted surface with good drainage capabilities reduces the chances of this happening significantly.

Finally, redirecting rainwater toward ditches and gutters instead of onto roadways and highways helps create a safer driving environment for all drivers and passengers. So next time you're out driving on the highway, remember that those slight inclines are actually there to help keep you safe!


Slanting roads are a common yet sometimes perplexing part of our highway landscape. But, when you understand the underlying reasons why highways are slanted, you can better appreciate the benefits they bring. Slanting roads increase visibility for drivers, enhance drainage, help reduce the risk of accidents, improve road grip, and prevent water accumulation.

Whether you drive down the highway all the time or just occasionally, knowing why slanted roads exist can make your trip safer and smoother. Remember, the slight incline of the highway is designed to help you, so take the time to appreciate why it’s there and how it makes your journey easier.

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