The Embedded Higher-order Agent (E-HoA) architecture presented in this paper addresses the growing need for context-aware ambient systems, such as autonomous vehicles. This multi-process architecture, to be embedded into the control loop of these vehicles, includes a Belief-Desire-Intention agent that can consistently assist the symbolic execution of intentions. It also performs the appropriate conversion of these intentions into real physical vehicle maneuvers based on ROS. The proposed architecture offers gradually 4 levels of reactivity, from arch-reflex to the deep modification of the previously built symbolic execution plan. The presented use-case, the daily delivery of a network of pharmacy offices by an autonomous vehicle taking into account contextual (spatio-temporal) traffic features, shows the efficiency and the modularity of the architecture, as well as the scalability of the reaction levels.