Today’s Wonder of the Day was inspired by WONDER FRIEND. WONDER FRIEND Wonders, “How to build a road?” Thanks for WONDERing with us, WONDER FRIEND!

Do you ever play with toy cars? They can be a lot of fun to race down a hall or across a room! Have you ever taken your toy cars outside to play? It can be fun to build your own roads for your cars to drive on. All you need is a rock or a toy shovel to clear a path for your cars to speed down like a highway.

It might be easy to make roads for toy cars. However, roads for real vehicles are much more difficult. Rocks and real shovels are involved, but it also takes quite a few people and a lot of special equipment to build a real road.

The first step in building a road is planning. Many people, including engineers and construction experts, are involved in this step. They decide what type of road should be made and what it should be made from. They do so by predicting the amount and type of traffic that will use it.

Even simple roads can take months of planning. Complex roads that include bridges or overpasses can take years. Other factors that planners must consider include environmental impact and cost of the road. They must also think about safety and the availability of materials.

Public meetings will also often be held. This is the chance for any citizens with concerns about the project to voice their opinions. The government entities building the road will also ask for construction bids from contractors. This helps them keep the cost down.

Once bids are compared and a contractor is selected, construction can finally begin! Depending on the size of the project, construction can take from a few weeks to several years.

The first part of construction is one of the most important: earthwork. Huge earth-moving machines must be used to create a solid foundation for road building. Without this step, any road built will fail long before its expected lifespan.

Bulldozers and graders move around dirt delivered by dump trucks to create a level surface. This will support a road for many years to come. Gravel is added in layers and machines roll over the surface to compact and flatten it further. Drains and storm sewers are also installed at this early stage. This helps the rain drain away from the road surface and makes it easier for vehicles to travel in storms.

Once the foundation is finished and has been inspected, it’s time to pave the way! The most common materials used for paving roads are asphalt and concrete. Factors such as cost and amount of traffic will determine which material is used.

Asphalt uses an oil-based substance called bitumen to make sand and crushed rock stick together like glue. After the asphalt is heated to about 300° F, it is moved to the construction site. There, construction crews spread and compact it onto the foundation already in place.

Concrete also uses sand and crushed rock, but it’s held together with cement. Workers must pour liquid concrete into special steel molds called forms. As it dries, a special finishing machine vibrates it to make it settle evenly and then trims it to the correct height.

To prevent cracks, workers make cuts—called joints—between concrete slabs. These joints allow the concrete slabs to expand and contract with changes in temperature without breaking.

Did you know so much work went into building a road? It’s quite the process! At the end, the new road is ready for many years of traffic and use. 

Standards: CCRA.L.3, CCRA.L.6, CCRA.R.1, CCRA.R.2, CCRA.R.4, CCRA.R.10, CCRA.SL.1, CCRA.SL.2, CCRA.W.2, CCRA.W.4, CCRA.W.9, CCRA.W.10, CCRA.L.1, CCRA.L.2

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