Gray, P. G. <br/><br/>
Drivers' understanding of road traffic signs / 
by P.G. Gray and R. Russell. 
 - [London :  Central Office of Information],  1962. 
<br/><br/> An inquiry covering England and Wales carried out for the Road Research Laboratory in October, 1962. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Traffic surveys -- Great Britain.--Traffic surveys -- Great Britain.<br/>Traffic signs and signals.