When you think about the environmental impact of roads, you might not exactly see the big picture Specifically, we need more than 5,300 tonnes of asphalt to build. If the road is made of concrete, only for the surface layer of one kilometer of a highway about 1,900 m3 of cement, aggregates, and water are necessary.
Research shows that the role of pavements in environmental impacts goes beyond the production of materials. For example, the amount of gas you consume for your car depends on the type of materials used.
Even more interesting, the type of coating used by your city administration can change your electricity bill in winter, as in summer! Yes, a lighter colored pavement can reduce the surrounding temperature and therefore, in the summer, reduce the use of air conditioner, saving electricity.
On the other hand, especially in colder areas, you may need to use more electricity to heat your home in winter due to the lighter color of interurban highways. Surprising and perhaps unknown!
To evaluate the environmental aspect of pavements, experts use the life cycle analysis, a holistic tool that gives us all the data on the environmental impact from the moment the builder starts supplying the materials to the end result.
Several criteria change during the life of the road and could influence the environmental impact
When assessing the environmental impacts of the pavement, it is more important to implement the detailed dynamic life cycle assessment because, during the life of the road (about 50 years), several criteria will change depending on the age and also, the use of the roadway.
For example, we know that if the temperature decreases due to the lighter color of the roadway, in winter, more electricity will be consumed. However, we should import it from the United States since we are already using all the current capabilities in Quebec.
But in the long run, if electricity demands changes because of the decreasing temperature, the government has already planned wind turbines to cover this increase in electricity demand. As a result, the technology and the environmental impacts corresponding to the evolution of electricity consumption for tomorrow and for 20 years later are different.
Another example of dynamic changes, from the point of view of civil engineering, is that when we drive our cars on the road, we change the quality of the surface and, as a result, we have more roughness on the surface over time. Other pavement characteristics, such as surface color, may change over time.
The bituminous asphalt surface will have a lighter color due to abrasion and the color of the concrete will become darker due to the driving of the vehicles.
In conclusion, there are more important factors influencing the environmental impact of the road construction beside the intrinsic ones related to construction material production and transportation.
Erin VanDyke lives on her family farm and has more than 35 years of hands-on experience with the use of livestock guard dogs for predator control. On their farm, Jan and her family use corgis as herding dogs and have raised Shetland sheep, Fainting goats, Morgan and Trakehner horses, and historic breeds of chickens and turkeys. Erin is also an active beekeeper.