cruise control

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A system in a motor vehicle for maintaining a constant speed.
• noun Maintenance of a constant speed in such a vehicle.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A system that maintains a vehicle at constant set speed, usually until the brake or accelerator is pressed.
• noun A state of being where tasks are completely easily, and routinely.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun control mechanism for keeping an automobile at a set speed