Visual Problems in Streets and Motorways

Experiments were made to determine (1) the ways in which a vehicle driver uses his eyes when driving and the information he needs, and (2) the means by which this information is conveyed to him in various lighting systems, including daylight, on English urban highways and motorways. The mechanism of seeing in empty roads, medium traffic and heavy traffic have been elucidated, and the effectiveness of daylight, twilight and street lighting appraised. Differences of driving requirements on the motorway and in urban roads were found. It was concluded that vehicle lights were not capable of providing information necessary for safe driving on the motorway if an emergency occurs, but that fixed lighting was capable of doing so. The necessary characteristics of this fixed lighting are discussed.