Design of a smart safety device for dangerous traffic situations

Abstract

The project “Design of a smart safety device for dangerous traffic situations” focused on vulnerable road users under the age of 18 years. When participating in traffic as pedestrians, bicyclists or as the drivers of motorized 2-wheelers children are vulnerable, especially towards heavier motorized traffic (i.e. cars, busses and trucks). In the analysis the target group was specified as children, age 12–15 years, who go to secondary school by bicycle in The Netherlands. Motorized traffic and distractions (e.g. peers, music, cell phones) are threatening. Furthermore, children at the age of 12 are easily distracted and they do not always pay attention. The children most fear cars, especially when crossing an intersection or when cars pass. The safety device is a pair of earphones that warns the child for a vehicle that approaches from behind. These are outside the visual field and cannot be heard while listening to music. The device warns the child using sound. The design has a similar appearance and size as the popular type of earphones. The user is warned by a beep with an increasing repetition frequency mixed in with the music. The detection of motorized vehicles is done using sound. This detection was tested in experiments where different car types, velocities and road types are used. Also the effect of wind on the recording was tested and optimized. The final design consists of earplugs and an in-wire control unit which houses the electronics and one AAA battery for powering. There is an on/off and sensitivity switch. The earphones are made of injection molded plastic and silicon rubber which shields the microphones and gives comfort to the ear tips. The potential target group gave feedback on the functionality and aesthetics of the final design. This group recognized the usefulness of the earphones. The warning signal is distinguishable from music, although this largely depends on the type of music. The signal is clear in terms of approach of vehicles. The children saw no problems for using this product on a bicycle. Regarding the aesthetics different colors were favored to match the MP3-player. Opinions about the size of the earphones differed. In general, the children would spend between 15 and 35 Euro for it.