Within the road traffic management industry - those involved with designing roads and putting signals (or traffic lights in layman's terms), Adaptive Engineering refers to the practice of designing signals and controlling their operation to achieve the most efficient time allocation to each approach within an intersection's cycle time to make sure traffic build up is avoided.
An intersection's cycle time is divided into phases with some being mandatory and some being "introduced" when required such as a pedestrian pushing a button to indicate he wants to cross at the intersection. The Controller at that intersection records the fact and makes sure the pedestrian is serviced by "introducing" a pedestrian WALK phase.
The ability to "configure" a controller's personality at every intersection allows the controller to "adapt" to the changing traffic conditions and alter the cycle time on a real time cycle-by-cycle basis.
In contrast, a fixed time system is NOT adaptive as it ALWAYS performs an action such as putting in a pedestrian WALK phase whether a pedestrian in there or not.