California needs to rethink its urban fire strategy

A wildfire in Wrightwood, California, in 2016. Image: Getty.

In October, we witnessed the wind-driven Tubbs fire blast its way through densely urbanised neighborhoods in Northern California, causing dozens of fatalities and thousands of home losses. This tragic event easily ranks as the most catastrophic fire in modern California history. Stories of how fast the fire spread and how little time people had to evacuate are stunning.

Despite how unusual the devastation appears, we need to recognise that these structure-to-structure “urban conflagrations” have happened in the past and will happen again. Yet these fires revealed that we have key gaps in our policy and planning related to assessing risk in fire-prone environments.

What is increasingly clear to fire researchers like me is that losses on the human side are often driven by where and how we build our communities. This means we must learn to coexist with fire, if we are going to inhabit fire-prone landscapes, just as we adapt to other natural hazards. An essential step is to shift our perspective from a focus on hazard to one that more comprehensively includes human vulnerabilities.

Mapping risk

California is leading the way in mapping the danger that wildfires pose to human communities and, in particular, linking building codes to fire severities that may be expected in given location. The state’s Fire Hazard Severity Zone maps are an essential step in recognising fire as an inevitable process that must be accommodated, similar to how we plan for floods, landslides, earthquakes and hurricanes.

What is missing from these maps, however, is extreme weather patterns. The Santa Ana winds of Southern California are a notable example. Strong, hot and dry wind episodes are associated with nearly all of our largest and most destructive wildfires, including the 1964 Hanley fire in Northern California that burned an almost identical footprint to the Tubbs fire, yet relatively little is currently known about how often they occur across a landscape.

 

Updating maps on fire risk should inform urban development. Image: Cal Fire/creative commons.

 

New methods are becoming available for mapping and modeling winds, and future versions of the Fire Hazard Severity Zone maps will therefore include such weather conditions. Similar maps are also needed for fire-prone areas outside California.

Despite technical advances, a key problem with most mapped approaches to fire danger is that the focus is almost exclusively on characterising the hazard – flame lengths, rates of spread or fire intensities of an oncoming wildfire – and much less on the vulnerabilities of what is actually exposed. The “wildland-urban interface,” where developed lands are exposed to natural, flammable areas, is thus often mapped and assumed to be where the exposure ends.

Clearly this is not always the case. Analogous to when a levee fails, after a wildfire manages to ignite homes along the wildland-urban interface, many homes farther inside the neighborhood can quickly become exposed.

Depending on the building codes in place during their construction, these newly exposed structures may or may not be very fire-resistant. Their vulnerability to ignition can also be especially high if they are spaced closely together and the winds are strong, because that is when fire spread transitions to a structure-to-structure domino effect.

Better fire risk mapping means we should be able refine our notion and approach to assessing vulnerability.

Reducing human exposure

There are numerous reports of how difficult and deadly it was to evacuate during the Tubbs fire. Apparently many people had almost no warning at all. This highlights the importance of both evacuation planning and evacuation communication systems, as getting out in time is what Americans tend to rely on in wildfire situations.

Although evacuation preparedness is nearly always mentioned in Community Wildfire Protection Plans and standard guidance for home owners, the overriding message is typically to “leave early” whenever possible.

While absolutely correct, this advice minimises the importance of pre-fire evacuation planning and the short time there may be to get out. It takes quite a bit of thought and effort to anticipate being in such a crisis situation.

What should one take, and where might one actually go?

On short notice, how does one account for pets, children or the elderly?

Is there a place one should retreat to, if evacuation orders are received too late or not at all?

This last question may be the one that gets the least attention, and the many fatalities in the Tubbs fire suggest that it requires much deeper consideration. Firefighters are often given specific training about what to do with limited evacuation options. For homeowners, however, guidance can be sparse.

When it is too late and too dangerous to evacuate safely, fallback options must be considered and communicated ahead of time. In an urban conflagration situation, local details dictate whether “safety zones” actually exist as places to take refuge. Given the real potential for such disasters, many communities should consider identifying (or building) key “hardened” structures to act as local-scale refuges.

Reducing human exposure involves more attention to what people must do during a wildfire, or even the rare urban conflagration. Safe evacuation deserves as much emphasis as reduction of fuels, such as creating defensible space around homes or larger scale fuel breaks by thinning vegetation around communities.


A safer built environment

From the scale of individual home construction up to the location and arrangement of development on a landscape, our communities should be better able to survive the natural hazards that occur there. This requires both short- and long-term strategies for achieving a safer built environment.

As a starting point, we must acknowledge that we currently have tens of thousands – possibly even hundreds of thousands – of homes constructed according to building codes that leave these structures vulnerable to ignition. Amazingly, however, there are very few examples of grant programs to mitigate such vulnerabilities through retrofit programs to, for instance, replace wood shake shingle roofs or to upgrade attic and crawlspace vents to block embers from entering homes.

In contrast, there are millions of dollars in public funds spent annually on community-scale fuel reduction projects. These are common activities pursued by Fire Safe Councils in California and similar organisations in other states.

The same level of support should be available for mitigation of fire-related structure vulnerabilities as there is for hazards.

Over the long term, land use planning is probably the most effective tool available for creating safer communities. We must be more deliberate about how we develop on fire-prone landscapes, taking advantage of emerging hazard-mapping techniques.

The goal here is not necessarily to build fewer homes, but to design and site developments that avoid the highest hazard regions and concentrate development in the lowest hazard areas. This logic applies, to varying degrees, to constraining development with respect to other natural hazards.

Despite an aversion by some to land use planning, this strategy is simply common sense. It will also save lives and massive amounts of public resources over the long term.

Where we do choose to develop and inhabit hazard-prone environments, it may be necessary to design communities with “passive survivability” in mind, or the ability to withstand the event and have water and power for a few days. This provides both the built environment and the people within some basic protection for a limited time.

The ConversationStrategies exist to lower the risk of fire in the current housing stock and to more carefully design and site future development where wildfires are possible. With increasing extremes expected as climate continues to change, officially recognising this link and creating a safer built environment will only become more urgent.

Max Moritz, Cooperative Extension Specialist, Wildland Fire, University of California, Berkeley.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

Cycling on London’s Euston Road is still a terrifying experience

Cyclists on the Euston Road. Image: Jonn Elledge.

The New Road, which skirted the northern boundaries of London’s built up area, first opened in the 1750s. Originally, it was intended to link up outlying villages and provide a route to drive sheep and cows to the meat market at Smithfield without having to pass through the congested city centre. 

As with bypasses and ring roads the world over, however, it increasingly became congested in its own right. Today, you won’t often find livestock on the route, which is now Marylebone, Euston and City roads. But you will find up to six lanes of often stationary buses, cabs, and private vehicles. In a city whose centre is largely free of multi-lane highways, London’s northern ring road has long been the sort of abomination that you avoid at all costs.

But now, somewhat surprisingly, the road is seeing yet another new use. Earlier this week, the first phase of a temporary cycle lane opened on the Euston Road, the middle section of the route which runs for roughly a mile. As London rethinks roads throughout the city, this addition to the cycling map falls solidly into the category of streets that didn't seem like candidates for cycling before the pandemic.

It is, to be clear, temporary. That’s true of many of the Covid-led interventions that Transport for London is currently making, though those in the know will often quietly admit to hoping they end up being permanent. In this case, however, the agency genuinely seems to mean it: TfL emphasized in its press release that the road space is already being allocated for construction starting late next year and that "TfL will work with local boroughs to develop alternate routes along side streets" when the cycle lane is removed.

At lunchtime on Friday, I decided to try the lane for myself to understand what an unlikely, temporary cycle lane can accomplish. In this case it's clear that the presence of a lane only accomplishes so much. A few key things will still leave riders wanting:

It’s one way only. To be specific, eastbound. I found this out the hard way, after attempting to cycle the Euston Road westbound, under the naive impression that there was now a lane for me in which to do this. Neither I nor the traffic I unexpectedly found myself sharing space with enjoyed the experience. To be fair, London’s cycling commissioner Will Norman had shared this information on Twitter, but cyclists might find themselves inadvertently mixing with multiple lanes of much, much bigger vehicles.

It radically changes in width. At times the westbound route, which is separated from the motor traffic by upright posts, is perhaps a metre and a half wide. At others, such as immediately outside Euston station, it’s shared with buses and is suddenly four or five times that. This is slightly vexing.

It’s extremely short. The publicity for the new lane said it would connect up with other cycle routes on Hampstead Road and Judd Street (where Cycleway 6, the main north-south crosstown route, meets Euston Road). That’s a distance of roughly 925m. It actually runs from Gower Street to Ossulton Street, a distance of barely 670m. Not only does the reduced length mean it doesn’t quite connect to the rest of the network, it also means that the segregated space suddenly stops:

The junction between Euston Road and Ousslston Street, where the segregated lane suddenly, unexpectedly stops. Image: Jonn Elledge.

 

It’s for these reasons, perhaps, that the new lane is not yet seeing many users. Each time I cycled the length of it I saw only a handful of other cyclists (although that did include a man cycling with a child on a seat behind him – not something one would have expected on the Euston Road of the past).


Though I hesitate to mention this because it feeds into the car lobby’s agenda, it was also striking that the westbound traffic – the side of the road which had lost a lane to bikes – was significantly more congested than the eastbound. If the lane is extended, it could, counterintuitively, help, by removing the unexpected pinch points at which three lanes of cars suddenly have to squeeze into two.

There’s a distinctly unfinished air to the project – though, to be fair, it’s early days. The eastbound lane needs to be created from scratch; the westbound extended. At that point, it would hopefully be something TfL would be keen enough to talk about that cyclists start using it in greater numbers – and drivers get the message they should avoid the Euston Road.

The obvious explanation for why TfL is going to all this trouble is that TfL is in charge of the Euston Road, and so can do what it likes there. Building cycle lanes on side nearby roads means working with the boroughs, and that’s inevitably more difficult and time consuming.

But if the long-term plan is to push cyclists via side roads anyway, it’s questionable whether all this disruption is worth it. A segregated cycle lane that stops without warning and leaves you fighting for space with three lanes of buses, lorries, and cabs is a cycle lane that’s of no use at all.

Jonn Elledge was founding editor of CityMetric. He is on Twitter as @jonnelledge and on Facebook as JonnElledgeWrites.