On a four-lane road with a single solid white line, what is permitted?

In the context of road markings, a solid white line is primarily used to indicate areas where changing lanes is discouraged. On a four-lane road with a single solid white line, overtaking by passing over this line is typically not allowed in many jurisdictions. However, in some instances, there may be exceptions where passing over a solid line for overtaking is permitted if specified under particular circumstances, such as in the case of an emergency vehicle responding to a call or certain marked conditions.

The other options are not permissible under normal driving conditions. Driving in the opposite direction on a lane marked by solid lines violates traffic regulations, as drivers must follow the designated direction of travel. Parking on the road is usually prohibited in areas marked with solid lines, as it can obstruct traffic and pose safety hazards. Likewise, using a lane for emergency stops should adhere to local traffic laws, which may designate specific areas or situations where such actions are suitable, rather than permitting usage of lanes marked with solid white lines for that purpose.