If, as Rebecca Solnit once wrote, "home is everything you can walk to," those who live in highly connected cities — with lots of tightly packed, four-way intersections — have a lot more home to roam. Such grids provide an inherent efficiency in time, distance and navigability for people on foot, creating "clearer and more direct pedestrian routes," states one recent academic paper on this subject. In contrast, the cul-de-sacs and looping roads of suburbia may help reduce vehicle traffic jams, but "their discontinuity inhibits pedestrian access to facilities and amenities, while their curvilinearity lengthens and confuses walking trips."
For the same reasons, gridded street networks are also more efficient for public transit. It's with that mode in mind that DW Rowlands, a graduate student in human geography at the University of Maryland, Baltimore County, has been taking a quantitative approach to the study of urban connectivity. As part of her thesis research, she has mapped the street intersections in eight U.S. cities to reveal how some have inherent disadvantages that planners seeking to provide high quality transit service can't always overcome with more buses alone.
"When we compare transit ridership in two cities, we’re often conflating two things," she said. "It's the quality of transit, but it's also a function of the types of neighborhood that they're serving."
Rowlands used OpenStreetMaps street network data to code the number of roads that meet at every intersection. The X-ray-like results reveal the underlying structures that keep some of the country's largest human settlements moving — efficiently, in the case of older cities like New York City or Chicago, or inefficiently, in the case of a newer, auto-centric cities like Atlanta or Tampa. (Of course, in some cases, poor bus service can take an evenly gridded street network and make it harder to navigate.)