EVERYONE agrees safety devices such as seat belts or airbags can be helpful in the event of an accident, but it is also indisputable that accident prevention is inherently superior. Avoiding accidents requires keeping your full attention on the road. Even a brief interruption should be avoided. If you look down at the instrument panel while driving at 80 to 100 km/h, it takes almost 0.5 seconds before you look up and react to what you see on the road again. At that speed you will have travelled about 14 metres. Precisely because so much can happen during that time, Nissan developed its Head Up Display (HUD) technology. Since you see the HUD through the windshield there is no need to look down, and ''blind time'' is cut by more than 40 per cent to less than 0.3 seconds. The world's first HUD for mass-produced cars came from Nissan's research and development division in 1988. A few United States manufacturers soon began to offer HUD as an option and from the end of 1991, Toyota's expensive Majesta line had an HUD with limited features. The main advantages of Nissan's new HUD - available for Bluebird models in Japan - over other makes are more information displayed, higher visibility, greater speed-indication accuracy and integration of the instrument panel's analogue speedometer and the HUD's digital speedometer. Nissan believes HUD can do more than tell you how fast the car is moving. What car today does not have a radio and a cassette player? And what driver has not had a close call while fumbling with multi-position temperature controls? Nissan is designing methods to simplify their operation. Activating one switch will, for example, result in an HUD radio dial and controls. The driver can select stations by pressing conveniently located buttons without taking his eyes off the road. Activate a different switch and the temperature/air conditioning controls will appear. Safe and intuitive mapping of HUD images and the physical controls is a complex task, but Nissan engineers have confidence in the practical potential for HUD applications and believe the technology will make great contributions to safe, more pleasurable driving.