What does the term "friction course" refer to in asphalt pavement?

The term "friction course" refers specifically to a surface layer designed to enhance the friction and skid resistance of the pavement. This layer is typically constructed using a dense graded mixture that is designed to provide a rough texture, enhancing tire-pavement interaction and minimizing the likelihood of skidding during wet conditions.

This aspect is particularly important for ensuring road safety, as a high-quality friction course can greatly improve a vehicle's traction, especially on curves and during adverse weather conditions. The materials used in this layer are selected not only for their durability but also for their ability to provide optimal surface texture, which is crucial for maintaining adequate friction levels over time.

While other options may refer to relevant practices in asphalt paving, they pertain to different aspects, such as recycling methods or drainage improvements, rather than the specific intent of improving friction and skid resistance.