  The dynamics and processes of urban morphogenesis are a central issue
regarding a long-term sustainability of urban systems. They however imply
stakeholders and parameters at multiple temporal and spatial scales
simultaneously, leading to intricate interactions between dimensions and
scales. We introduce in this paper from a theoretical viewpoint a simple
agent-based model of urban morphogenesis at the scale of an urban area, with
the feature of integrating the microscopic and the mesoscopic scales. At the
local level, developer agents drive urban development conditioned by local
properties but also an infrastructure network at a smaller scale. The network
evolves more slowly following global properties. Indicators of sustainability
including modal shares and urban density suggest an application of the model to
multi-objective optimisation. We finally discuss possible implementation,
extensions and applications of the model.
