A new international standard aims to improve the ease with which drivers can recognise text and symbols from the displays in cars while they are in motion, thus decreasing mental workload and visual distraction.
The standard, ‘ISO 15008:2003, Road vehicles – Ergonomic aspects of transport information and control systems – Specifications and compliance procedures for in-vehicle visual presentation’ provides specifications for the image quality and legibility of displays under different viewing conditions – daylight, dusk and night conditions. In addition, it addresses the overall appearance of texts and symbols, including character contrast, size, spacing, stroke width, and colour.
For example, it advises that red characters on blue backgrounds should be avoided since the eyes will have trouble focusing on these colour combinations. Deep reds can also be confusing for people who are colour blind.
According to Gary Rupp, Chair of the subcommittee that developed the new standard, visual displays can have an important impact on the driver’s behaviour and potential safety.
‘If the information is not legible, drivers will likely spend more time looking at the display and less time looking at the roadway. Driving can be adversely affected when the driver is distracted or overloaded which may result in situations where their actions, or lack of actions, increase the risk of an accident.’
‘ISO 15008 will therefore help ensure that visual displays used in transport information and control systems are legible before they are put on the market for customer use.’
ISO 15008:2003 costs 102 Swiss francs and is available from ISO national member institutes and from the ISO Central Secretariat. The new standard is the work of ISO technical committee ISO/TC 22, Road vehicles, subcommittee SC 13, Ergonomics applicable to road vehicles, working group WG 8, TICS on board – HMI.