Though some people would go great distances to see old cars, Inquirer travel contributor Michael Milne has crisscrossed the continental United States multiple times to visit automobile museums.

The result is probably the most thorough book about them yet written.

The self-published Roadster Guide to America's Classic Car Museums and Attractions offers an in-depth look at more than 250 places where car lovers can get their motor-head geek on - so it seems like the ideal piece for die-hard automobile fans.

But it's also a travel guide for people on the road looking for something different.

"It deviates a little bit to things that aren't car museums, like Cadillac Ranch in Texas and Carhenge in Nebraska," Milne said in a Skype interview. "You don't have to be a car person - just like quirky travel sites."

Milne was available live via satellite because he and his wife, Larissa, were in Bucharest, Romania, for a few months. They've spent the last five years as "nouveau homeless," traveling the United States and the world, writing about the adventure for a variety of publications, including the Inquirer.

They are regular gatherers of compendiums of information.

They had written Philadelphia Liberty Trail: Trace the Path of America's Heritage, published in 2014 by Globe Pequot Press. The publisher approached them with an idea for a Philadelphia trail modeled after Boston's Freedom Trail. The Milnes had to cull the sites themselves, because no such trail existed in the City of Brotherly Love.

This time around, Milne used the couple's own imprint, Changes in Longitude Press, to keep more control over the book, because publishers these days are not offering a lot of support for writers.

Milne didn't visit all the museums in the book - some were closed when he was there - but he did get to most of them.

"We spent two years, and we drove coast to coast four times," he said. "I can say with confidence that no one has been to more car museums than I have."

He doesn't have a set strategy for his reviews, he said. In some places, he'd show up anonymously; in others, he'd contact the staff in advance and arrange a tour. Writers often get to go behind the ropes and see the cars up close.

One of his standout favorites was the Gilmore Car Museum, tucked away in Hickory Corners, Mich. It's the largest among the hundreds in the book - a consortium of 12 museums in one location, with about 400 vehicles in half a dozen buildings, Milne said.

"Some of the national car clubs have their museums on the grounds. It's really like a college campus."

But, Philadelphians, fear not - there's no need to travel far to see some great examples of automotive history. Plenty of great museums have their headquarters nearby.

Milne recently wrote about the Tucker Trail, museums around central Pennsylvania where people can see five examples of the 1948 Tucker 48 made famous in the 1988 Francis Ford Coppola film elegy to the wannabe automaker. Only 51 were built, although some people contend that Tucker was less a visionary than a shyster who took people's money and ran.

Milne also gave a shout-out to the Simeone Automotive Museum in Eastwick, which he called "one of the best auto-racing museums in the world."

With more than 250 museums to fit into the book, there's not a lot of room for the fun local flavor that make the Milnes' newspaper columns such a treat. But he still manages to pack in plenty of history about each museum. Side trips take people to an old Studebaker dealer in New Jersey, one-lane Route 66 in Oklahoma, and Carlisle, Pa.

Milne includes a photo of the Mister Softee truck from the Boyertown Museum of Historic Vehicles, which is housed in the Berks County factory that built every example of the treat-bearing, music-jingling trucks. Milne even notes where to download the song as a ringtone (www.mistersoftee.com).

The Milnes' articles have appeared in National Geographic's Intelligent Traveler, Huffington Post, AAA, Go Magazine, Hemmings Motor News, American Airlines, Serious Eats, and other media outlets.

Mike McNessor, who edits Milne's monthly column at Hemmings, cites as a reason to buy the book the writer's dedication to uncovering information.

"He's really one of the most professional freelancers I've worked with (clear, approachable writing, good photos) yet has a good grasp of what car enthusiasts might be looking for in a road trip or a roadside attraction," McNessor said in an email. "Michael's research was exhaustive, and his knowledge of the destinations in the book is excellent."

Now that this book has made it to the shelves, auto lovers might want to update their passports for the next Milne work.

He told me about a museum he has visited in Bucharest that features many Rolls-Royces and Bentleys.

"Potentially," Milne said, "there's another edition of this book."

"Roadster Guide to America's Classic Car Museums and Attractions" can be purchased through changesinlongitude.com, Amazon, or about 20 of the museums featured in its pages.