Which gate type is designed for secure vehicle access and allows entry through a narrow passage?

The correct choice is the sally port, which is specifically designed for secure vehicle access. A sally port consists of two secure gates or doors in a confined entryway, allowing for controlled access and enhanced security. When the first gate closes, it creates a secure space where a vehicle can be checked before the second gate opens, ensuring that unauthorized entry is prevented. This feature is particularly important in high-security environments, such as military bases or secure facilities, where maintaining strict control over vehicle access is necessary.

In contrast, other types of gates mentioned do not serve the same purpose. Sliding gates are typically utilized in residential or commercial properties for general vehicle access but lack the added security features of a sally port. Vehicle swing gates also provide access but do not have the secure entry process that a sally port employs. Personnel door gates are designed for human access rather than vehicles and would not be suited for secure vehicle entry situations. Thus, the sally port stands out as the most appropriate answer for controlled and secure vehicle access through a narrow passage.