An easy way to tell how long a city has been around is to look at it from above: modern cities tend to have wide, even street grids that are easy to navigate by car. Ancient cities like Rome, by contrast, look like a pile of spaghetti from a bird’s eye view. It’s not just an aesthetic difference—it’s fundamentally easier to walk around the small blocks of downtown Manhattan (where the Dutch first established a trading post in 1624) versus the wide lanes of Irvine, California, a master-planned suburb built in the 1960s. To get a better idea, check out these grid maps by UC Berkeley city planning researcher Geoff Boeing (as spotted over on FlowingData).

Boeing’s visualizations compare aerial views of different cities around the world through one-square-mile snapshots, created using an algorithm that pulls from OpenStreetMap. The unified scale of the visualizations makes it easy to quantify how walking around different places feels. City blocks differ in both size and shape. An aerial view of downtown Paris looks like a windshield that just had a bad encounter with a flying rock. A similar view of Portland looks like a chicken-wire fence. If you look closely, you can compare the width of streets and highways:

The maps also show where even the most uniform city grids are interrupted. Since the 1960s, Portland’s dense, walking-friendly blocks have had a giant highway cut through them. Atlanta, too, is a tangle of highways. San Francisco is filled with alleys, as is Tunis.

If you look at all of the grids, you can see the difference between cities that were meticulously planned and those that sprang up organically. Dubai and Sacramento look like they were drawn by a city planner’s pencil, but Osaka and Boston clearly expanded more haphazardly over the centuries. The symmetrical boulevards and diagonal side streets of Paris are the result of the 19th century plans of Georges-Eugène Haussmann, who was hired by Napoleon to help remake the city.

They are all a good reminder that the easiest cities to get around don’t always have the simplest maps. Rome may look like a tangle of winding streets, but that tight network is much easier to traverse than the very few streets that intersect in a square mile of Irvine’s street grid. And from street level, those tiny blocks tend to look a lot more interesting than big suburban intersections.

[h/t FlowingData]

All images courtesy Geoff Boeing