The connection between the badge icon on the map and the image icon is used in .json file.
All icons icons defined in highway_signs.png image files found in the "Normal", united together as sprites:
"badges" : [ { "columns" : 2, "filename" : "highway_signs.png", "id" : 59, "rows" : 8, "textcolor" : "FFFFFF" } ],
and then each icon uses a different “icon” from a different position
"text" : { "badge" : { "badgeid" : 59, "badgetype" : "#0#1", "color" : "FFFFFF", "fontid" : [ 3, 3, 3, 3 ], "fontid3d" : [ 7, 7, 7, 6 ], "format" : "#1", "horizontal" : true, "outlinecolor" : "ffffffff", "position" : "path", "spacing" : 400 } }
key being the line "badgetype" : "#0#1" , which indicates that we will use the image of the first row (0-based row index), the second column (column 0 on the basis of indices).
If you want to change the badge icons, modify the highway_signs.png file. If you want to remove icons from the map - delete elements "icon" of the definitions of road elements.