Effects of extra signals on drivers´ distance keeping-a simulation study

One hundred and twenty-one older drivers (ages 55-86) followed a lead car in a driving-simulator. They were asked “to keep at a safe and comfortable distance” behind the lead car, to respond if they wished to a separation indicator which provided a visual signal when the lead vehicle was closer than 26 m, and to cancel a distracting light. When the older drivers´ performance is compared to that of a control group of 25 younger drivers (ages 30-44), it is found that the ability to match the varying speed of the lead car of most of the older drivers is indistinguishable from that of the younger drivers, but that a few older drivers have a substantially worse performance. Any additional task reduces performance of all the drivers but the older drivers were able to use an indication of the distance between the cars to reduce the effect of the distracting task