Neat!
All numbers but the 2dis are underlined, since they're linking to pages. Should the underline be taken out or kept to show it's clickable?
The business interstates don't have shields but do have the state names. The US Auxiliary routes are the opposite case, with shields but no identifying information unless you hover. For example, I have nine 61's in a row, and the Business 63 Ottumwa icon is blank for some reason.