Motivated by the recent surge in vehicular ad-hoc
network (VANET) research and the promise of high-impact
applications such as safety, navigation and infotainment services,
we consider the impact of mobility mis-modeling on the design
and development of this class of distributed systems. Focusing
on urban environments, we use a state-of-the-art car traffic
simulator to extract some of the key connectivity metrics relevant
for the design of a vehicle-to-vehicle traffic information system.
We compare such metrics against those obtained from popular
mobility models, such as the random waypoint model and the
Manhattan mobility model. Our results reveal striking differences
in the connectivity profile of the network, thus casting some doubt
on the adequacy of simple mobility models for the development
of future VANET protocols.