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A Tesla drives towards a row of homes ablaze on the Pacific Coast Highway during the Palisades Fire. (Photo by Anna Sophia Moltke / SOPA Images / Sipa USA via AP Images)
It’s an unforgettable scene from the Palisades Fire: The screech of metal-on-metal as cars abandoned on Sunset Boulevard are pushed aside by a bulldozer. Residents stuck in gridlock left their vehicles to flee on foot during a mass evacuation, blocking the way for emergency response vehicles.
For UCLA urban planning professor Adam Millard-Ball, that scene of gridlock illustrates a familiar problem: Sprawl and the car dependency it requires. His research paper, “A high-resolution global time series of street-network sprawl,” was just released on Jan. 13.
Millard-Ball and his colleagues mapped street connectivity, including the dead ends, cul-de-sacs and loops that decrease it, worldwide. He couldn’t help but notice that the neighborhoods that struggled to safely evacuate are also some of the least connected in L.A. County, with only a few ways to get in and out.
Predictably, this causes potentially deadly gridlock during a disaster, forcing both fleeing residents and emergency vehicles into the same chokepoints.
But street sprawl also has important climate impacts, locking people into car dependency and making it harder — if not impossible — to walk, bike or take the bus. For Millard-Ball, the wildfires are a chance to rebuild more connected streets that also improve disaster response.
“It would be a lost opportunity if we build the streets back exactly the way they were before,” he says.
Why does street sprawl exist?
In the post-war era, Americans flocked to the suburbs in search of the American dream, and with it, embraced cul-de-sacs and even gated communities with a single access point.
“We found that the U.S., actually, has some of the least connected streets in the world,” says Millard-Ball. Los Angeles is an exception, with a generally well-connected grid system — except in places like the Pacific Palisades.
“People often like that because of privacy and perhaps some perceived safety from crime,” Millard-Ball notes. “But it means that there’s no alternative to driving, and again, in an emergency, it’s much harder to get out.”
In L.A. County, suburban communities often exist on the urban fringe or the wildland-urban interface where fire can be a constant threat.
In some cases, the street sprawl is due to the topography. In other cases, it was a design choice. This means that planners can make different choices during the rebuilding phase instead of merely repeating the mistakes of the past.
Some possibilities Millard-Ball mentions: Making it safer for kids to walk or bike to school, building pedestrian paths between neighborhoods, adding more shade for bus riders, planting different trees and using materials that are less water-intensive and mitigate urban heat. Improving street connectivity isn’t just a project for areas devastated by wildfires — the whole city could benefit.
“The connectivity in much of L.A. is about overcoming barriers, like freeways in particular, so providing safe ways to walk and bike through freeway underpasses, which are really scary as a pedestrian and often not very safe,” says Millard-Ball.
There has been some controversy in L.A. over improvements for people walking, biking and taking transit. With Measure HLA, a voter-approved initiative to, in part, add more bus and bike lanes, firefighters and some city leaders claimed that this would impede emergency response vehicles.
“[Adding bike or bus lanes] doesn’t really affect emergency response,” says Millard-Ball, “Because with good street design, fire trucks can drive in the bike lane or the bus lane.”
As for common concerns that more street connectivity means more unhoused people or more crime (when in fact, research shows that unhoused people are more likely to be victims than perpetrators of crime), Millard-Ball says he’s not aware of any research linking them.
“There’s streets that are part of an old-fashioned grid that have very few homeless people.”