What is the purpose of edgelines along the roadway?

Edgelines along the roadway serve the important function of marking the limits of the traveled roadway. These lines help drivers to know where the edge of the road is, which is especially useful in situations where the road may not have a defined shoulder. By clearly delineating this boundary, edgelines contribute to overall road safety by guiding drivers and reducing the likelihood of vehicles accidentally veering off the road. This clarity is vital in various driving conditions, such as at night or during inclement weather, where visibility may be compromised.

The other options focus on different aspects of roadway design, such as bike lanes, parking areas, and the separation of opposing traffic, which all serve specific purposes, but do not reflect the primary intent of edgelines. Therefore, the correct choice highlights the essential role of edgelines in defining the physical limits of the roadway for safe navigation.