Summary: Pervasive applications must be aware of the contexts where they are executed. These contexts may vary greatly and change quickly. Two main problems are associated with this issue: (1) context-awareness is a crosscutting concern that cannot be well-encapsulated in a single module using traditional technologies, thus hindering software maintenance and reusability; and (2) reasoning about application design correctness can be complex due to the number and diversity of potential contexts where a pervasive application could be executed. In order to overcome these problems, we present a process for the design and implementation of context-aware pervasive applications that uses aspect-orientation and executable modelling in order to overcome these shortcomings. Aspect-oriented techniques contribute to the encapsulation of crosscutting concerns, such as context-awareness, into well-localized modules. Executable modelling helps engineers to reason about application design by executing the design models in different contexts and situations. Pervasive applications are modelled using the aspect-oriented executable modelling UML 2.0 profile, executed at the modelling level for testing purposes, and then mapped into an aspect-oriented middleware platform for pervasive applications. This process is illustrated using a location-aware intelligent transportation system consisting of a set of cooperating sentient vehicles.