Not Legal Advice: It means that you need to stay within the lane. It also marks the shoulder of the roadway.
A single solid white line on the road divides lanes of traffic traveling in the same direction and discourages lane changes. White lines divide lanes of one-way traffic, and yellow lines divide lanes of two-way traffic.
As per Mlive.com, “shoulder” means that portion of the highway contiguous to the roadway generally extending the contour of the roadway, not designed for vehicular travel but maintained for the temporary accommodation of disabled or stopped vehicles otherwise permitted on the roadway.
The shoulder is not the main-traveled portion of the roadway so passing on the shoulder is not allowed.
Traffic signs come in many shapes, sizes, and colors. With so many different traffic signs on the road, you might lose track of what each one means.
Fortunately, the shapes and colors of traffic signs can help you understand their meaning. Shape up your traffic sign knowledge with these tips shared by Dmv.org.