What is a Road Base Driveway? Why is it Used?

Patrick Casey

By patrick casey

Last Updated on February, 2025

If you are planning to pave a driveway, you must have heard about road base. Are you wondering what it is? If YES, you’re in the right place. 

After reading this article, you’ll know:

  • What exactly a road base is.
  • How it is constructed.
  • Pros and cons of a road base.
  • How to choose the right material for the road base and; 
  • The latest advancements. 

Let’s get started.

Quick Summary

  • A road base is a foundational layer made of crushed rock, gravel, or other materials placed between the subgrade and the top layer in various constructions, such as driveways. It provides structural support, distributes weight, and enhances drainage.
  • The road base is laid and compacted above the subgrade, ensuring stability and durability for the driveway. It requires maintenance over time, but when properly constructed, it offers long-term benefits like reduced maintenance needs.
  • Key factors to consider when choosing a road base material include climate, budget, traffic volume, and the level of maintenance required. Alternatives like asphalt or crusher dust may be more suitable depending on specific needs, offering different benefits and costs.

What is a Road Base in Driveways, And Why is it Used?

Gravel Road Base in Driveways

Road base is the layer between the subgrade and the top layer in various constructions, including driveways, walkways, paving substrates, parking areas, etc. 

Road base mainly consists of crushed rock and gravel, but various other materials can be used for construction. It’s a mixture made up of large rock fragments, fine particles, and dust. 

A road base plays a vital role in road construction projects. Below are some of the benefits of road base:

  • Provides structural support to the driveway, helping it withstand heavy traffic and adverse weather conditions. 
  • Distributes the weight of the vehicles evenly to maintain the road’s structural integrity and prevent cracks.
  • Provides better drainage allowing rain and flood water to flow freely. This prevents erosion and damage caused by standing water. 
  • If you apply a proper road base, the driveway will require low maintenance. 

Overall, the road base provides safety, stability, and durability to driveways. 

How are Road Base Driveways Constructed? 

In driveway construction, a road base is added above the subgrade. The subgrade is the natural soil that lies beneath the road surface, and it functions as the foundation of the road surface. 

Before adding the road base, the subgrade is added and compacted to the proper level. Next, the base material is spread over to an approximate 100-250 mm thickness. 

It’s then compacted and water-bound using a roller or a compactor to get the desired density and stability and give an even finish. 

The pavement layer is spread above the road base. Hence, after the road base is added, it’s tested to verify whether it’s durable enough and meets other specific requirements. 

Even though the road base is tightly bound at the beginning, it may loosen over time. However, you can repair it and use it for a long time. 

When to Use a Road Base in a Driveway?

Crushed stones used in a Driveway

Road base commonly consists of decomposed granite, crushed gravel, and limestone. Hence, it’s used as a foundation for heavy structures such as main roads, building pads, slabs, hardstand areas, parking lots, etc. 

You can use a road base for both paved surfaces and non-paved driveways. 

When Not to Use a Road Base in a Driveway?

If you have heavy traffic, the road base driveway can become loose and uneven. You must repair it regularly. Ensure you are willing to spend money on repairs. If not, a road base is not the right choice for you. 

Moreover, a road base driveway can get waterlogged during the rainy season and dusty in summer. You must consider the climate in your area and whether you can manage a dusty environment. 

Road Base Materials for Driveways

Types of road base materials used in a Driveway

Different types of base materials are used for road base driveway construction. Below are the most common ones:

  • Crushed gravel

Gravel is the most commonly used base material for unpaved driveways. Its smooth texture allows for an even distribution of the material with few sunken areas. 

  • Recycled concrete

Concrete has a smooth texture and is similar to gravel. However, concrete has some advantages over gravel. Recycled concrete is easy to compact, is eco-friendly, and more affordable. 

  • Crushed stone

Crushed stone doesn’t have a smooth texture like gravel, instead it’s jagged. Hence, crushed stone will have an uneven appearance when spread and compacted with subgrade. 

  • Crushed brick

Crushed brick also has a jagged appearance but is more affordable and eco-friendly. If you have a limited budget, you must consider this option. 

  • Stabilised soil

This type of soil is mixed with other materials to create a road base for driveways.

Factors to Consider When Choosing the Right Road Base Material

Rural road base driveway

There are various types of road base materials and you may wonder which is best for your driveway. To select the best road base for your driveway, consider the factors below. 

  • Climate

Climate is a significant factor when choosing a road base material. 

Suppose you live in an area with very high temperatures. You must select a material that will withstand high temperatures. If you live in an area with heavy rainfall and storms, you must select a material that drains water easily, such as gravel or crushed stone. 

If you live in a place with heavy snowfall during winter, your driveway will be subjected to road treatments such as heating and salting. So, you have to select a durable material for the above treatments. 

  • Availability

Typically, your local store will only have road bases suited to the climate in your area. Hence, you must select one of those. 

  • Budget

The prices of the road bases are a crucial factor in deciding which one to use in a project. 

Gravel and crushed rock are the two most expensive road base materials. 

Some base materials might have low upfront costs, but they can cost you more in the future due to frequent maintenance and repair. Therefore, when selecting a road base, you must consider the durability and long-term effects. 

  • Traffic

You must consider the traffic volume and the type of vehicles when choosing road base options. 

Driveways with high volume and heavy truck traffic need more durable materials, while a less expensive, thin material would be enough for a driveway with less traffic. 

You must consider all the above factors carefully and select the most suitable material for your driveway. Remember, the wrong road base material will need frequent maintenance, which will cost you more in the long run. 

Pros and Cons of a Road Base Driveway

Gravel road base driveway

Below are the pros and cons of getting a road base driveway. 

Pros

  • Affordable. You can use different materials for your driveway construction project, so you can choose a material that suits your budget. 
  • Easy to install. 
  • Get rid of gaps and potholes, providing a good surface for water drainage. 
  • There are eco-friendly road base options to choose from. 

Cons

  • It requires maintenance. Over time, your driveway will get damaged, and potholes may form. Maintaining it is important to make it last longer. 
  • If you are using gravel-like material, grass and weeds can grow. You must trim them occasionally to keep your driveway clean and neat. 

Latest Advancements in Road Base Driveways

Using recycled materials, plant-based materials, and geo-synthetic materials are some of the latest advancements in road base materials. These new advancements aim to increase durability and reduce cost. 

Geosynthetic materials like geogrids and geotextiles are added with traditional road base materials to increase stability and strength. 

Using recycled materials, such as recycled concrete and asphalt, reduces environmental pollution and they are affordable compared to other traditional materials. 

Some plant-based materials, like wood chips and coconut fibres, are mixed with sand and gravel to make affordable road base materials that have the same structural integrity as the traditional ones. 

Cost of Getting a Road Base Driveway Done

Gravel road base driveway used in a house

Typically, the cost of getting a road base driveway in Australia is around $10-$30 per square metre, depending on several factors. Let’s look at them. 

  • Size and layout 

If your driveway is large, you’ll need more materials and more labour, resulting in more cost compared to small driveways. Moreover, if the driveway has slopes and curves, it’ll cost you more. 

  • Land preparation

The surface must be graded and levelled before spreading the base mixture. Sometimes, the existing rocks and stones must be removed before applying the new base. These processes will cost you more. It takes around $35-$55 per square metre to remove an existing driveway. 

  • Land composition

The roadbase is laid on the soil surface. Therefore, the composition of the soil impacts the amount of base mixture required. For example, if your soil primarily has sand and gravel, you can reduce the installation cost by 25%-60%. 

  • Location

The location of your driveway impacts the cost. If it’s near the road, it’s easy to supply materials. If not, you will have to pay additional delivery charges. If you require multiple deliveries, the price will increase further. 

  • Type of material used

For driveway construction, you can use concrete, gravel, limestone, or asphalt-like materials. The cost will vary depending on the material’s price. 

Alternatives to a Road Base Driveway

asphalt driveway
  • Asphalt 

Asphalt is an alternative to road base. It’s a mix of aggregate and sand bound by bitumen binder. 

Below are some advantages of asphalt over road base in driveways, paving substrates, slabs, etc:

  • More durable and gives a smoother finish.
  • Needs less maintenance and repairs. 
  • Gives an aesthetically pleasing look.
  • Adds value to your property.

Asphalt is best for driveways above 150 square metres in size. Why? When the area increases, the cost per square metre is reduced for large properties. 

  • Crusher dust 

Crusher dust is a more affordable alternative to road base. It’s made of recycled concrete mixed with soft sand and a non-porous material. 

Crushed dust made with crushed rock is cheaper than crushed dust made of discarded rock.

Crushed dust is a good surface material for unsealed driveways, walkways, and paths. It’s also an excellent packing material to install around water tanks and pavers. You can use crushed dust in garden beds to increase the mineral content. 

Whether or Not to Get a Road Base Driveway?

Constructing a Gravel road base driveway

Whether to get a road base driveway or not depends on several factors. Below are some of the questions you must ask yourself before deciding. 

  • Is your budget enough to install the driveway? 
  • Is the climate in your area suitable for a road base driveway?
  • The driveway will be filled with dust in summer and potholes during the rainy season. Can you manage these conditions?
  • A road base driveway requires regular maintenance. Are you able to maintain it and willing to spend money on the repairs? 
  • How much traffic do you have, and what type of vehicles do you have? 

You must weigh the pros and cons carefully and make the right decision. 

Other useful guides:

Summary

A road base is a foundation laid on top of the subgrade in driveways, slabs, pavers, etc. 

A road base is typically made of concrete, gravel, or limestone. When choosing a material for the road side base, you must consider the climate, budget, traffic, and the nature of the material. 

Asphalt and crusher dust are two alternatives to road base that you can use in your driveway. Geosynthetics, plant-based materials, and recycled materials are some of the latest advancements in road base construction. 

When installing a driveway, consider your budget, the size of your land, the climate in your area, the level of maintenance required, and the repair costs. 

FAQs

A road base is used to create a hard, compacted surface on top of the subgrade, distributing vehicle weight evenly and preventing cracks and deformation.

Asphalt is more durable and easier to maintain, while road base is cheaper. The best choice depends on your budget and desired features.

Gravel is the best base for a driveway, providing a smooth finish and effective water drainage.

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