Technological advancements in transportation and communication played a significant role in facilitating the expansion of imperial control by:

Transportation:

1. Steamships: Introduced in the 19th century, steamships enabled faster and more reliable transportation of goods, people, and military personnel across the globe, facilitating the expansion of empires.
2. Railroads: Built in many colonies, railroads enabled the rapid movement of troops, supplies, and goods, allowing empires to maintain control over vast territories.
3. Aircraft: The development of airplanes in the early 20th century enabled empires to quickly respond to crises and maintain control over distant territories.

Communication:

1. Telegraphy: The introduction of telegraphy in the mid-19th century enabled rapid communication between distant locations, facilitating the exchange of information, orders, and instructions between colonial administrators and military commanders.
2. Radio: The development of radio communication in the late 19th century enabled real-time communication between ships, military units, and colonial authorities, further facilitating imperial control.
3. Satellite communications: The advent of satellite communications in the mid-20th century enabled near-instant communication between distant locations, further enhancing imperial control.

These technological advancements enabled empires to:

1. Maintain control over vast territories: By facilitating rapid transportation and communication, empires could maintain control over distant territories and respond quickly to crises.
2. Establish colonies: Technological advancements enabled empires to establish colonies in distant regions, facilitating the extraction of resources and the spread of imperial influence.
3. Suppress resistance: By rapidly communicating orders and responding to crises, empires could suppress resistance movements and maintain control over colonized populations.
4. Facilitate trade and commerce: Technological advancements enabled empires to facilitate trade and commerce between colonies and metropolitan centers, generating revenue and further solidifying imperial control.