Most people hardly give road maps a second thought, except when they happen to fold one the wrong way and it springs from the glove compartment like a caged bat. Likewise, in the study of cartography they have been mostly footnotes-at least until now, with the opening of a show called “The Power of Maps” at the Cooper-Hewitt Museum in New York, the National Museum of Design. Co-curator Lucy Fellowes has unearthed rare treasures from antiquity, and the only slightly less remote 1960s, represented by a map of the East Coast with south at the top. This made it easier for Miami-bound tourists to figure out which way to turn without turning the map around and trying to read the names upside down. The point of the show is that maps never reflect a neutral reality; in choosing what to show and how to represent it, they subtly shape our perceptions of the world. This is most clearly seen in the medieval Christian maps that subordinated physical geography to cosmology, putting “Hope” in the north, “Faith” in the east, “Charity” in the south and water in the west. The same point is made by the beautiful stick charts of the Marshall Islands: networks of shells, representing islands, linked by sticks that signify prevailing ocean swells. But it is equally true, according to co-curator Denis Wood, of such humble and seemingly straightforward documents as a North Carolina state highway map. An entire room of the exhibit, in fact, is given over to Wood’s elaborate deconstruction of the maps of that one innocent state, posing the ominous question: “Whose agenda is in your glove compartment?”

To Wood, a professor of design at North Carolina State University, the answer is obvious: state highway maps are “advertising documents for the notion of moving around the country by road.” Look at them, he urges, webbed over with red and blue highways, colors that convey a subliminal correspondence to the vital arteries of the body. While the natural assumption is that roads were built first and then mapped, Wood contends that the opposite also happened. Before there were through highways, there were only local roads. By stringing them together on the map, Wood says, mapmakers in effect called highways into being; the actual roads had to be improved to match what had been drawn. Anyone older than about 30 remembers the road maps of the 1950s and ’60s, crossed by dashes representing the interstates of America’s glorious, traffic-free future. “A map,” says Wood, “is something that prompts and promotes the use of roads, making it necessary to have more roads.”

Wood, author of a book also called “The Power of Maps,” is clearly something of an extremist on the subject. He travels around Raleigh by bicycle and got a driver’s license only in the past year. But he makes some provocative points, for instance, in his comparison of a highway map from the mid-1980s with a contemporaneous map of public-transit routes. The former was full of pictures of attractive young white families frolicking in North Carolina’s famous beaches, rivers and golf courses, while the latter showed such characteristic features of bus travel as waiting lines, conspicuously populated by blacks and the elderly. “Between 1945 and 1990,” a prominent label in the exhibit notes, “63,511 people died on North Carolina highways. IS THERE A BETTER WAY?”

Undoubtedly there is, although it’s not apparent that there would be fewer traffic accidents if people got lost more often. For the record, Wood disputes even the basic utility of a road map for the purposes of navigation. He believes that people ordinarily get directions to their destinations and mentally chart their surroundings as a series of left and right turns. That’s probably true for most places you can reach by bicycle, but most Americans planning a trip to another state feel more secure with a map in their pockets, even if their actual driving is limited to the road from the airport to their hotel. Maps, as the show demonstrates many times, serve a variety of functions, not all of them completely innocent. But most people also like to know where they’re going.