Twenty-two inexperienced drivers participated in a laboratory test aimed at testing their comprehension of road signs for parking regulations. Half of the subjects were first presented with road signs in use in sweden, they were then presented with the same signs with additional text on the signs. The presentation order was reversed for the other half of the subjects. In each trial the subject indicated which hours stopping was prohibited, parking was prohibited, parking 15 minutes was allowed, parking 45 minutes was allowed, and parking was charged. The results were in fair agreement with the results of a previous study showing that about 20% of the signs were not fully comprehended. The number of errors was reduced to about 10% when the subjects received feedback. It was more common for the subjects to indicate that they were not allowed to park, when they were, than to indicate that parking was allowed when it was not. Additional text decreased the number of errors but it also, to some extent, increased response times. The positive effects of additional text could not be given a non ambiguous interpretation and they were not sufficiently important to warrant a general recommendation as a means of improving comprehension of the type of road signs investigated. (Author/publisher)
Abstract