Visual collision warning displays in industrial trucks

This paper presents a study of the impact of different visual warnings on brake reaction times and perceived workload in industrial trucks. Four different warning signals for collision avoidance are investigated. A warning light in the drivers front forward field of vision, a warning light based on an existing collision warning system and two peripheral warnings based on LED bars are compared. Numerous studies in automotive research have shown that LED bar generated peripheral warnings show advantages in comparison to conventional warnings in head-down displays and head-up displays. Reaction times and driver distraction can be reduced. We transfer these warning concepts from the automotive car interior to the driver cabin of industrial trucks, in this case of an forklift truck. Since many forklift trucks are equipped with data terminals for order instructions, we apply a visual-manual secondary task (SuRT) to test potential impacts and interactions of the terminal operation. Results show that brake reaction times in our setup are lower when warnings are displayed by the LED bars and also when the driver is not distracted by the secondary task. We found no interaction between the different warning displays and the secondary task.