Accidental tourist: David Whitley

Prowling around a university campus on a Sunday afternoon in search of a particularly large brain isn't, I concede, most people's idea of a good holiday. But given there's nobody around to tell me to do something 'better' — like getting sand-encrusted everything on a beach, or trawl around the 15th quite pretty church in six days — I feel entitled to indulge my whims.

The Cornell University campus in Ithaca, New York, is a city in itself. And on a Sunday afternoon, it feels like a city that's been evacuated after a meltdown at a nearby nuclear power plant. There's not a book-packed satchel or scruffily-clad future captain of industry in sight. When I finally find the social science building, Uris Hall, it feels worryingly like I'm trespassing and could be shot by an over-zealous security guard at any moment.

On the second floor is the Wilder Brain Collection, an assortment of grey matter acquired by a former professor of neurology and vertebrate zoology. They sit in jars perched along dusty alcove shelves on a dull institutional corridor. And they're oddly fascinating, especially when you read the accompanying labels. Helen Hamilton Gardiner's brain, according to the blurb, confirms 'the claims of many women that the brain of a woman need not be inferior to that of a man'.

Another, looking like a particularly unappealing cake made out of snakes, belonged to Edward Ruloff. At 1,770g, it's the second largest brain ever recorded and serves as proof that intelligence is not always put to good use — Ruloff murdered his wife and daughter, carried out a string of robberies and was eventually hanged for shooting two store clerks as he attempted to raise funds to get his academic thesis published.

The joy of the US is that it's crammed full of unheralded oddities such as this. Bomb down any interstate and it's a fair bet that at any point you're a maximum of half an hour away from something charmingly weird. The Land of the Free is also the land of the freaky — stuffed with things no one in their right mind would fly over especially to see, but, when strung together as part of a road trip, become a stream of skewed wonder.

I have to go to Boston and Chicago. The logical thing to do would be to hop on a two-hour flight between the two. But logical is boring, so I hire a car and spend a week tackling a route that features on precisely zero lists of Great American Road Trips.

Forget following a prescriptive itinerary along Route 66 or the Pacific Coast Highway — that's not what a true road trip is about. Rather, stick two pins in a map and make up your own route between them as you go — chances are it'll still be great. And probably for reasons you're not expecting.

Instead of being a grim slog through Rust Belt misery, staying in motels with bedsheets bearing the bloodstains of the last murdered guest, the journey turns out to be one of near-ceaseless beauty. The whole fall foliage thing, I discover, isn't restricted to New England — that's just the region that spends big bucks on marketing it.

What also make the disorganised long-distance trundle so special are chance discoveries — often stumbled upon after rifling through guide books and tourist leaflets the night before.

I found myself getting thwacked on the thumb in baseball batting cages at Cooperstown, New York, then making glass with the ham-fisted decorative skills of a gorilla in boxing gloves at Corning, a few miles further west.

The refinery stench of northwestern Pennsylvania leads me to Titusville, the birthplace of the US oil industry. Blue collar pro football and rock 'n' roll halls of fame in Ohio give way to rural heartlands of big farm country houses, one of which happens to be where US inventor Thomas Edison was born. Michigan offers up block-long street art among eerily abandoned houses in Detroit, plus arguably the world's best collection of modern artifacts, at Dearborn's Henry Ford Museum. It includes civil rights activist Rosa Parks' bus and the car JFK was in when he was assassinated.

That I felt sad when I finally arrive in Chicago — a city I adore — says everything. These road trips are never about the destination; they're about the freedom to veer off the path from prescribed sanity to whimsical self-indulgence. And if that means looking at massive brains in dusty jars, so be it.

Published in the May/Jun 2013 issue of National Geographic Traveller (UK)