What do edge and lane lines on the road signify?

The correct choice highlights that edge and lane lines are primarily used to delineate the borders of the roadway. Edge lines are typically used to denote the boundary of the road itself, helping drivers to stay within the safe driving area, especially in low visibility conditions or during night driving. Lane lines, on the other hand, indicate the divisions between different lanes of traffic, guiding vehicles on how to navigate safely and effectively.

This function is crucial for maintaining order on the road and ensuring that vehicles stay within designated lanes, contributing to overall traffic safety. Understanding the role of these lines enhances a driver's ability to obey road rules and manipulate their vehicle appropriately within the designated roadway space. The other options, while related to road use, focus on different functions: speed limits pertain to permissible driving speeds, traffic laws encompass broader regulations governing vehicle operation, and lane width is more about road design than the function of lane markings.