The highway markers used by all U.S. states and territories, as well as the Interstate highway and U.S. Route shields (click to enlarge). Many state highway markers are designed with the respective state's geographic shape in mind, or are based off of a particular state symbol (i.e. the highway markers used in Kansas are sunflower-shaped, as the wild sunflower is the state flower of Kansas). Most of the U.S. states use generically rectangular or neutral shape for their state highway markers, and the circular highway shield (which is how state highways are indicated on most maps) are used by the states of Delaware, Iowa, Kentucky, Mississippi and New Jersey and the territory of the U.S. Virgin Islands for signage on their respective highways. Generally, state highways are low-capacity thoroughfares that run across the state or in specific localities, although some state highways are built as expressways or up to Interstate Highway standards if the traffic volume on the route is su...