Which type of line indicates that passing is not allowed?

A solid line is used to indicate that passing is not allowed. This type of line is typically found on roadways where visibility is limited, or where it is dangerous to overtake another vehicle. The solid line serves as a clear warning to drivers that they should remain in their lane and not attempt to cross over into the opposing lane to pass. This helps maintain safety by reducing the risk of head-on collisions in areas where passing could be hazardous.

In contrast, a broken line typically indicates that passing is allowed, as it signifies that drivers can change lanes when it is safe to do so. Arrows serve different purposes, often indicating directions of traffic flow or lane usage, while a dotted line is often associated with the merging of lanes and does not directly indicate passing restrictions. Understanding these distinctions is crucial for safe driving practices and complying with road regulations.