Conceptually, a Driver Support System (DSS) for road vehicles should behave like a cooperative human copilot. A DSS should continuously monitor the driver, the vehicle, and its environment in order to inform the driver in time about upcoming major decisions regarding navigation and potentially risky traffic situations. A DSS should relieve the driver of distracting routine activities like tracking the vehicle's position for navigation purposes and warn him about impending threads. In principle, the DSS should be able to drive automatically -- given a suitable situation like stop-and-go traffic on a straight, intersection-free, unidirectional road -- if so desired by the human driver, but still under his final responsibility.
Significant advances have been realized -- for example during the European EUREKA project PROMETHEUS (PROgraMme for a European Traffic with Highest Efficiency and Unprecedented Safety, 1986 -- 1994) -- towards turning qualitative ideas like the ones mentioned in the introductory paragraph into engineering specifications for the design and realization of such a DSS. Similar experiences have been accumulated, too, in the course of research programs which have been initiated since then in Japan and in the USA, for example the Intelligent Vehicles Highway System (IVHS). Although these broad research programs do not concentrate on Computer Vision (CV) in the context of road vehicle surveillance, guidance and safety, the technology-driven exponential rise of computing power at roughly constant -- if not decreasing -- cost, power, and space consumption fuels the exploration of CV in this context.
A fundamental operation of CV for driver support consists in the real-time detection and tracking of images of road and vehicle structures recorded by a video-camera. Since about the mid-nineties, this can be achieved by a standard workstation under carefully controlled conditions. In view of the extremely stringent safety requirements for routine use of such approaches on public roads, it is no surprise that more computing power than currently available in a car will be required in order to provide the necessary robustness. On the other hand, experts expect that CV will be introduced into selected regular road vehicle categories still within the next decade. Although a market for CV-based DSSs has not yet been established, precursors are likely to show up soon. Since a DSS will be a component of cars, buses, and trucks, the automobile industry together with its parts and components suppliers constitutes the primarily relevant industrial sector for this technology.
Obviously, it is still too early to reliably estimate market sizes and growth rates for CV-based DSSs. It is tempting, however, to speculate about the boundary conditions for such a market in the future.
Due to the continuous push towards increased efficiency, safety, and comfort in road vehicles, all kinds of electronic devices have already begun to invade the automobile. It thus appears natural to assume that many of the hooks required for the installation of a DSS -- such as, for example, sensors and medium to high speed digital buses as well as electronically activated actuators (drive-by-wire) -- will already have been introduced into cars independently of a DSS.
An order of magnitude estimate for the DSS market proper might be provided by the following consideration: the cost of a DSS will be proportional to that of a video-equipped Multimedia PC as it is sold today for less than 10 000 DM. On the hypothesis that the price for such equipment will be halved -- even with substantially increased capabilities -- during the next five years due to the booming consumer market, it would correspond to about 10 % of the price of an upper middle class sedan and an even smaller fraction of the price of a bus or truck.
On the assumption that initially less than 1 % of all road vehicles newly produced worldwide per year will be equipped with a DSS at the price tag of 5 000 DM, about 200 000 to 300 000 such systems might be sold annually -- which would constitute a market worth about a billion DM, starting possibly already in five years. In analogy to the introduction of radios, AntiBlockingSystems (ABS), or automatic gear shifts into automobiles, it does not appear irresponsible to predict a further halving of the price tag for a DSS over the ten year period following its introduction, accompanied by an annual increase in the fraction of road vehicles equipped by such a system from 1 % to 10 %. Ten years from now, this would yield a rate of 5 % of the annual road vehicle output or 2 million DSSs per year, corresponding to a market of 4-5 billion DM annually worldwide. Even under the assumption of drastically falling prices, this would result in a sustained period with 50 % growth of the DSS market annually after its introduction. Since this market constitutes an add-on market -- i. e. it does not require to install a completely new sales and maintainance organisation from scratch, but may gradually evolve from current vehicle electronics -- the figures do not appear outright unrealistic.
The roots of Computer Vision for DSS may be traced back to research about vision-based mobile robots in the late sixties and early seventies. Since the computing power which could be made available on a mobile platform was very limited at that time, the initial flurry of interest abated after some years. Only very few groups continued to work in this area until the digitization and processing of video images became more amenable to experimentation at the beginning of the eighties. The ambitious DARPA `Autonomous Land Vehicle' program re-invigorated civilian research efforts towards vision-based autonomous mobility for indoor as well as outdoor vehicles. This in turn stimulated CV-research for vehicle guidance in the PROMETHEUS framework which had been conceived to cover all aspects of road traffic, not only automatic driving -- see, e. g., [Parkes & Franzen 93].
Thorpe ([Thorpe 90]) provides an overview of research at Carnegie Mellon University related to vision-based autonomous road vehicles. This book may simultaneously serve as a representative description of approaches studied during the eighties. A roundtable discussion during the Summer 1990 in Tokyo resulted in a book `Vision-Based Vehicle Guidance' [Masaki 92]. This roundtable discussion gave rise to a series of annual `Intelligent Vehicles Symposia' sponsored by the IEEE Industrial Electronics Society. The proceedings of these symposia, starting in 1992, provide an immediate access path to international reseach results related to DSS. Very valuable information can also be gained from a special issue on `Network, Control, Communication and Computing Technologies for Intelligent Transportation Systems' edited by [Amin et al. 95].
A comprehensive, very well balanced assessment of PROMETHEUS efforts has been published by [Braess & Reichart 95]. An in-depth, two volume treatment of contributions by German AI research groups to PROMETHEUS, including CV in the context of driver support systems, can be found in the final PRO-ART report edited by [Nagel 95].