Smooth Roads Save Money and Significantly Decrease Carbon Emissions

The Oregon Department of Transportation and Oregon State University recently discovered that roadway smoothness matters more than most people think. Less energy is needed to drive on smooth roads, which results in drivers purchasing less gasoline and emitting fewer emissions.

Although a simple principle, the magnitude of the financial and carbon savings is surprising. Notably, the research incorporates Oregon’s plan to electrify vehicle fleets and accounts for the need to limit electrical grid demand in the future (i.e., it’s good policy to reduce energy use regardless of whether traditional fuels or electricity are the energy source).

​The bottom line is that for every dollar spent on paving there is a corresponding savings to drivers and a significant decrease in the energy needed to use the roadway system.

The Impact of Declining Roadway Conditions on Road User Costs and Greenhouse Gas Emissions, 2025.

Smooth Roads Improve Safety

​Smooth Roads Last Longer

​No research needed – smooth roads decrease accidents caused by motorists attempting to navigate distresses, hydroplaning, and help motorists anticipate breaking distances and necessary maneuvers.

Smoother roadways reduce the dynamic loads by minimizing commercial trucks’ vertical axle movements, which results in longer pavement life.
 

Modern Asphalt Plants Make a Difference

Asphalt plants heat and mix aggregates and asphalt binder according to an engineered mixture design. Because asphalt binder acts like a liquid when heated and is an elastic solid at normal temperatures, an asphalt plant’s primary purpose is to heat and mix. Aggregates enter and asphalt plant, get coated with asphalt binder, and then get transported to projects where the mixture is placed and compacted. As the binder cools, it transforms from a workable viscous fluid-like material to a solid. Aggregates are heated to ensure that they are dry when coated with asphalt binder because the binder won’t stick to wet aggregates. The drying process produces steam, which is often visible at an asphalt plant.
 
Asphalt binder comes from the crude oil refining process. When crude oil is refined to produce fuels and other products, the heavier parts of it are often leftover – and that material is the main component of asphalt binder.
 
Modern asphalt plants have burners to heat asphalt binder and aggregates in the mixing process. Almost all asphalt plants use natural gas as their burner fuel with some also using propane to heat the asphalt binder before mixing. Most asphalt plants also utilize a baghouse, which is a filtration system that captures dust/particulates and keeps them out of the air.
 
Asphalt plants generally heat the aggregates and asphalt binder to between 270 and 350 degrees Fahrenheit. Recently, many asphalt plants have adopted “warm mix” technology to allow for production at even lower temperatures. Because temperatures are not extreme, asphalt is 100% recyclable, and dust and particulates are captured in the baghouse, there are limited environmental concerns and no dangerous byproducts.  

What Are the Numbers?

The U.S. Environmental Protection Agency determined that asphalt plants are not a major source of hazardous air pollutants.

•  AP-42: Compilation or Air Pollutant Emission Factors, First Ed., Vol. 1, Chapter 11: Mineral Products Industry. 
• National Emission Standards for Hazardous Air Pollutants: Revision of Source Category List Under Section 112 of the Clean Air Act, Environmental Protection Agency, Federal Register, vol. 67, no. 29, pp. 6521-6536. 

The U.S. Department of Health and Human Services found that for very large asphalt processing and roofing manufacturing facilities (these facilities are much larger than asphalt plants and are considered major industrial emission sources) in North Carolina, there were no hazards to humans living in the vicinity.

• Review of the Incidence of Cancer Cases among Residents of Rowan County, North Carolina, and Residents Living Near Industrial Facilities in Salisbury, North Carolina

The emission control systems used at asphalt plants ensure that the air quality meets the applicable standards and pose no health or environmental risks to nearby communities.

• The Environmental Impact of Asphalt Plants

Asphalt plant Emissions fact sheet

Emissions Comparison Report

100% Recyclable

Most people would be surprised to hear that more asphalt is recycled each year than the combined amount of aluminum, glass, plastic bottles, and newspapers.

Every year in the US, close to 90 million tons of asphalt are recycled and used in either new paving projects or to make aggregate bases for other construction projects. 

Recycling used asphalt saves more than 3 billion dollars each year, keeps millions of cubic yards of reusable waste from taking up space in landfills, and results in emission decreases equivalent to taking more than half a million cars of the road.