<p>Many information technology artefacts can be found in today’s cars. The interaction with these artefacts is the driver’s secondary task while driving the car in a safe way is the primary task. When designing interfaces for in-vehicle usage, measures have to be taken in order to make the interaction with the artefact suit the in-vehicle environment. One of these measures is to have the appropriate screen density level, which is the amount of information present on the screen.</p><p>This thesis compares the usability of two integrated in-vehicle display prototypes, one with low screen density and one with high screen density. The usability comparison considers both safety and user preferences. Safety was measured by a Lane Change Test (LCT) which measures distraction of a primary task while performing a secondary task, and user preferences was measured with a questionnaire. Before the comparison was made, controls and a graphical user interface were designed.</p><p>Results showed no significant difference in driver distraction between performing tasks on the high screen density display and the low screen density display. However, a vast majority of the users preferred high screen density over low. Furthermore, the distraction levels for both the high and the low screen density displays were below the proposed 0.5 meter limit for allowed driver distraction. The results indicate that in-vehicle displays can have a high level of screen density without imposing a level of distraction on the driver that is unsuitable for driving.</p>

Many information technology artefacts can be found in today’s cars. The interaction with these artefacts is the driver’s secondary task while driving the car in a safe way is the primary task. When designing interfaces for in-vehicle usage, measures have to be taken in order to make the interaction with the artefact suit the in-vehicle environment. One of these measures is to have the appropriate screen density level, which is the amount of information present on the screen. This thesis compares the usability of two integrated in-vehicle display prototypes, one with low screen density and one with high screen density. The usability comparison considers both safety and user preferences. Safety was measured by a Lane Change Test (LCT) which measures distraction of a primary task while performing a secondary task, and user preferences was measured with a questionnaire. Before the comparison was made, controls and a graphical user interface were designed. Results showed no significant difference in driver distraction between performing tasks on the high screen density display and the low screen density display. However, a vast majority of the users preferred high screen density over low. Furthermore, the distraction levels for both the high and the low screen density displays were below the proposed 0.5 meter limit for allowed driver distraction. The results indicate that in-vehicle displays can have a high level of screen density without imposing a level of distraction on the driver that is unsuitable for driving.