This paper describes the design of the BASIS prototype system, which is currently under implementation. BASIS stands for {\bf B}enchmarking {\bf A}pproach for {\bf S}patial {\bf I}ndex {\bf S}tructures. It is a prototype system aiming at performance evaluation of spatial access methods and query processing strategies, under different data sets, various query types, and different workloads. BASIS is based on a modular architecture, composed of a simple storage manager, a query processor, and a set of algorithmic techniques to facilitate benchmarking. The main objective of BASIS is twofold: (i) to provide a benchmarking environment for spatial access methods and related query evaluation techniques, and (ii) to allow comparative studies of spatial access methods in different cases but under a common framework. We currently extend it to support the fundamental features of spatiotemporal data management and access methods.