Rubberized asphalt has been used on the SMF to provide a smooth driving surface. It has the added benefit of reducing noise levels by up to four decibels. This material—used for more than 20 years to resurface highways and city streets in Arizona—consists of regular asphalt pavement mixed with recycled rubber tires. In addition to the benefits it provides on the roadway, rubberized asphalt also reduces the number of used tires in landfills. Final rubberized asphalt paving will occur in the spring of 2020.