DAT 406 – Analyse an interface

Steering wheels and pedals of a car

Steering wheel

A car steering wheel is circular: a shape that invites rotation. The steering wheel can be rotated both left and right and this movement results in a corresponding movement of the car’s wheels allowing the driver to make changes of direction. The size of the steering wheel affords the easy placement of the driver’s hands. There is a mechanical limitation to the extent that the steering wheel can be rotated. It cannot be rotated in one direction indefinitely. There are generally limits of the speed that the wheel can be rotated so that opportunities for rapid changes of direction are limited.

Pedals

The pedals of a car are placed to allow the feet of a seated driver to operate them. On a manual car, the pedals are placed (from left to right): clutch, brake and accelarator. This layout is used, possibly due to the majority of people being right footed and an important function of the pedals is to accelerate the car, hence the accelator being the right-most pedal. The pedals only move on one axis: up and down. Pressing down on any car pedal actuates the function of that pedal, whilst releasing a pedal has the opposite affect, e.g. releasing the accelerator, stops power going to the wheels.