This next would be for the posted Alternate Routes; the numeral field and the banner switch colors.
This one would be for the Truck Routes, black for heavy trucking.
The next one would be for the Business Routes. Its field is green, the color of money. All Business and City Routes that link to the mainline at both ends plus all "Loop" Routes would be marked as "Business Loop" as shown. All mainlines that have Bypass Routes going around an urban area would also become Business Loops; the Bypasses would then become parts of the mainlines. Also, all Business and City Routes that link to the mainline at one end *only* plus all "Spur" Routes would be similarly marked as "Business Spur."
Now this one with the "TOLL" banner could be for tolled sections of mainlines that are not otherwise interstate quality. It could also be used for tollways if it is decided on a national basis not to use the two US route markers shown in the pervious post for the US freeways and tollways.
These last three are the pleasure-oriented travel routes, brown on white. The first of these three would be for the Historic Routes. The last two would be for Scenic Routes. An' a tip' o' the ol' hat to RVD of The Great International Highway Makeover for the last one -- his US Highways 1 to 830 webpage with its Route A1A idea inspired that last one!