  The ability to perform meaningful empirical studies is of essence in research
in spatio-temporal query processing. Such studies are often necessary to gain
detailed insight into the functional and performance characteristics of
proposals for new query processing techniques.
  We present a collection of spatio-temporal data, collected during an
intelligent speed adaptation project, termed INFATI, in which some two dozen
cars equipped with GPS receivers and logging equipment took part. We describe
how the data was collected and how it was "modified" to afford the drivers some
degree of anonymity.
  We also present the road network in which the cars were moving during data
collection.
  The GPS data is publicly available for non-commercial purposes. It is our
hope that this resource will help the spatio-temporal research community in its
efforts to develop new and better query processing techniques.
