Discussion of a new adaptive speed control system incorporating the geometric characteristics of the roadway Francisco Aparicio*, Javier Pa  ez, Fe  lix Moreno and Felipe Jime  nez INSIA-ETSII-UPM, Campus Sur UPM, Ctra. Valencia km 7, 28031 Madrid, Spain Fax: +34913365302 E-mail: faparicio@insia.upm.es E-mail: jpaez@insia.upm.es E-mail: fmoreno@insia.upm.es E-mail: fjimenez@insia.upm.es *Corresponding author Alberto Lo  pez Universidad Antonio de Nebrija, Departamento de IngenierõÂa Industrial, C/Pirineos 55, 28040 Madrid, Spain Fax: +34914521110 E-mail: alopezro@nebrija.es Abstract: In this paper different control systems are reviewed, classified and analysed as well as intelligent speed adaptation systems (ACCs, ISA), their objectives and prototypes implemented in different countries. After this discussion, an adaptive speed control system, based on the geometric characteristics of the road, is presented. The SAGE system, developed in the INSIA (University Institute for Automobile Research), consists of a real time electronic device for the driver information about the optimum driving velocity, taking into account driving safety criteria. These criteria have been defined considering the geometric characteristics of the road and the dynamic behaviour of the vehicle. The prototype developed is presented, and also its strategy and functions. Keywords: adaptive speed control; ADAS; driver interface; intelligent transportation systems. Reference to this paper should be made as follows: Aparicio, F., PaÂez, J., Moreno, F., JimeÂnez, F. and LoÂpez, A. (2005) `Discussion of a new adaptive speed control system incorporating the geometric characteristics of the roadway', Int. J. Vehicle Autonomous Systems, Vol. 3, No. 1, pp.47±64. Biographical notes: Francisco Aparicio obtained his PhD degree in mechanical engineering from the Polytechnic University of Madrid, Spain. He has been a Professor in the Department of Mechanical Engineering of Escuela Te cnica Superior de Ingenieros Industriales of UPM since 1981; Master Director in Vehicle Engineering from the Polytechnic University of Madrid since 1990; and a Director of INSIA-UPM since 1993. He is involved in national and international research and development Int. J. Vehicle Autonomous Systems, Vol. 3, No. 1, 2005 47 Copyright # 2005 Inderscience Enterprises Ltd.