When is backing up allowed on freeways or expressways?

Backing up on freeways or expressways is primarily permitted for drivers of emergency vehicles. This is because emergency situations may require police, ambulances, or fire trucks to maneuver in ways that ordinary vehicles cannot. The design and flow of traffic on freeways are such that backing up poses a serious risk to safety, leading to potential accidents.

In contrast, backing up is generally not allowed for other vehicles like taxis or during delivery situations, as it would create hazardous conditions on high-speed roadways, where the typical flow of traffic would be disrupted. It is crucial for all drivers to adhere to this rule for their safety and the safety of others on busy highways.