What feature characterizes a ladder truck compared to a regular fire engine?

A ladder truck is distinctly characterized by its inclusion of an aerial device and ladder system. This feature is vital for reaching elevated areas during fire incidents, enabling firefighters to effectively perform rescues and combat fires at heights that would be impossible with a standard fire engine. The aerial device, which can be a platform or a ladder, is mounted on the apparatus and provides additional reach and versatility in firefighting operations.

While features such as increased water storage capacity, highway travel design, and advanced firefighting foam capabilities are advantageous for various fire apparatus, they do not specifically define the unique function of a ladder truck. The primary role of a ladder truck centers around its ability to extend and position firefighters and equipment at higher elevations, making it an essential tool in urban firefighting scenarios.