Which? uses cookies to improve our sites and by continuing you agree to our cookies policy

Too may road signs may slow driver’s reaction

Study finds major impact of distractions

A triangular road sign.

Too many road signs could be making motoring more hazardous instead of safer, a study suggests.

The new research indicates that road safety could be improved if drivers were exposed to less distracting information.

Scientists investigated the effects of visual distraction from road signs and adverts on drivers’ reaction time.


A total of 54 male and female volunteers took turns in a driving simulator which provided different levels of distraction.

They were asked to execute a driving task while at the same time reacting to various road signs by means of a foot pedal.

The simulated journey had four distraction levels. ‘No load’ involved no distractions, ‘low load’ three distractions, ‘high load’ six, and ‘overload’ nine.

Reaction time

Significant increases in reaction time were observed between the ‘no load’ and ‘high load’ and ‘overload’ road conditions.

Researcher Oliver Clark, from the University of Hull, said: ‘One aspect of safe driving is the ability to react swiftly to dangers as they emerge on the road.

‘This experiment shows that too much visual information in the form of advertising and signage has an effect on reaction times – the more distractions there are the slower the reaction times of the driver. We should be aware that the plethora of advertising at road sides and signage may be contributing to road accidents.’

© The Press Association. All rights reserved

Back to top