This paper aims to show first why the automotive industry is the ideal marketplace for silicon micromachined sensors and, secondly, how the author expects this market to influence the development of micromachined sensors. The effect of digital sensor signal processing and the pressure of cost on circuit techniques is discussed, leading on to discussion of the benefits and drawbacks of integrating circuitry on sensor silicon. The author also presents his view that vehicle safety requirements will lead to all increased requirement for integrated sensor diagnostics and offers some possible implications for various types of sensor. (C) 1997 Elsevier Science Ltd.