I've now created A660 road so would be delighted if (A) you could create an icon for the A660, a primary route.  Other A6nn roads which currently have infoboxes with red links are (B) A666, A685, A690, plus A683 is linked from one of those.  Also there's a page with infobox for A6055.   There are other roads which have pages without infoboxes, possibly because there isn't an icon: (C) A605, 607, 612, 614, 625, 628, 630, 631, 635, 636, 638, 642, 647, 686, 6030, 6079.  I haven't looked in other regions, just the ones on the A6 region template.  So if you're willing to create any more icons, the (A,B,C) in this sentence indicate apparent priority bands for the A6 area.  (But basically, I'd just be very grateful if you could make one for my A660!).

 As an alternative: could someone create a mark2 version of the infobox template which makes the icon an option, so that people can produce a respectable-looking infobox even if an icon isn't available? Red links spoil the look of the page.  Thanks.