Last updated 24-2-2007
I have more or less arbitrarily selected 100 maps and atlases (or series) and noted which colours are used for motorways and other main roads. The selection is somewhat biased by the fact that my map collection has a strong weight on Germany and German maps. It turns out that for motorways, red lines with yellow is the most popular style (31 %). Other main roads are most often represented as single red lines (63 %).
Motorways are often represented by two lines, with a different colour in between. Other roads usually appear as single lines. In the table below, outline and centre colours are given for motorways and for the highest class of main roads (not dual carriageways). Often, the lines actually have thin grey or black lines on the edge, or in the middle. This is ignored, unless these are in sharp contrast with the main colours. Examples:
est = estimated year of publication
Most maps distinguish between motorways and other roads, but some display other roads with motorway characteristics (expressways) in the same way as motorways.
City maps typically have different colours than smaller scale road maps. The table below only contains only 8 city maps.
Most frequent motorway styles:
Remarks:
Rand McNally uses blue for free motorways and green for toll roads, this is counted as 0.5% each.
Blue is especially popular in the United Kingdom.
Most frequent colours for other roads: