It’s been said, “when what you have is a hammer, every problem looks like a nail.” My particular interest is street design, and I’m convinced most urban issues we could name can be addressed, at least in part, by rethinking the role and design of urban streets. No, really.
Consider a typical litany of current urban challenges: traffic safety, various transportation demands, climate change, air quality, increasingly severe urban heat waves, affordable housing, stormwater runoff, aging-in-place baby boomers, urban park deficits, water and energy conservation as well as pollution, local jobs, the obesity epidemic and its tremendous costs, crime, mental health, and social isolation. There is growing awareness that streets are an underutilized resource that could be tapped to address these and other issues.
About 25-30% of US urban land is entirely devoted to streets, sidewalks, and alleys. Streets represent the largest portion of undeveloped urban land, and it’s already publicly owned. Streets’ dominant function of moving vehicles comes at the expense of every other consideration. In what is probably a natural evolution, this is starting to change. Arguably, the most vibrant, economically healthy urban places (New York, Portland, Vancouver, Hong Kong, Singapore, most of Europe), don’t cater to, so much as tolerate, the automobile. It is thus no surprise that urban design improvements, which start with the public right-of-way, generally yield a high return on investment.
Safety vs. Speed
The single-purpose function of streets has a tragic downside, of course. In my opinion, Arterial streets are particularly frequently overbuilt. Their very size and design speed account for the fact that, in a recent year, 56% of urban pedestrian fatalities have occurred on these types of roads. In the last 20 years, studies have shown that traffic fatalities or crashes increase when the following occur: lanes are wider than 10-11 feet (the usual standard is 12), street width increases, shoulders are wide, lanes are added, curves are straightened, trees are removed, buildings are set back, and cul-de-sac neighborhood designs are employed. In other words, it appears that all the typical interventions used to increase capacity and/or improve safety make roads more, not less, dangerous. Fortunately, the treatments that render streets more livable – the opposite of those just listed – also make them safer and, if implemented widely, would free up considerable roadway space for other uses.
This became especially clear to me several years ago while reviewing the Padres Ballpark EIR. In a worst case traffic scenario – a game letting out during rush hour – the freeways serving downtown were projected to experience Level of Service (LOS) F, but the downtown streets would show LOS B. How is this possible? The grid pattern is the key, dispersing traffic into many available routes. This implies downtown has a lot of spare capacity that could be reallocated to wider sidewalks, bike lanes, a tree canopy, public art, linear parks, space for vendor carts, etc. In the process, the current 3-lane, one-way streets that tend to encourage speeding could be made far safer. The large annual cluster of pedestrian crashes downtown could be ameliorated, and the retail environment and quality of life enhanced, all without increasing congestion. That’s a far better deal than the Faustian bargain downtown has now, trading safety for speed.
Reducing VMT and GHG
Rethinking the function of streets has never been more critical. Laws requiring cities to reduce greenhouse gasses seem to be multiplying. On average San Diego generates far more CO2 per household than transit-rich cities like New York. SANDAG’s forthcoming response to California’s SB 375 to curb Vehicle Miles Traveled (VMT) means we need to get creative fast. Our current regional transportation plan projects a 30% increase in VMT by 2030. Once the state provides a VMT reduction target in June, per SB 375, we’ll need to somehow go the opposite direction while accommodating the increase in population. What role can streets play in this challenge?
Our cities and villages can create local street environments that encourage residents to replace long car trips with short ones and replace short trips with walking and bicycling. Transit can play a greater role, and safe, attractive streets are essential to a positive transit experience. Even in the recession, gas prices have inched above $3.00. Where will they go when the economy turns around? With a lack of cheap oil, the demand for other modes and local goods and services will only grow. Imagine the day when local shopping returns as the norm, and longer trips to save money on a roll of paper towels loses its appeal.
Let’s not forget that livable streets are “paved with gold”. Walkable neighborhoods with mixed uses and “third places” where people can linger have retained far more of their value during the recession. Walkability, and the sociability it fosters, is what people are hungry for. It follows that urban design treatments, including the streetscape, can help generate localized economic growth and jobs, especially if the era of global trade is interrupted by the exhaustion of a cheap oil supply.
Streets as Stormwater Filters
Streets guru Dan Burden says engineers care mostly about three things: drainage, drainage, and drainage. Indeed, during the 1990’s, local engineers, private and public, were consumed with capturing and handling stormwater runoff, thanks to new state requirements. In response, cities such as Seattle, Portland, and Chicago are installing “green streets” that allow water to percolate through the street itself or drain into bioswales, recharging the groundwater. This solution is far cheaper and more sustainable. Seattle, informally referred to as the “rainy city”, showed in a pilot project it can capture 99% of stormwater with this solution, in addition to achieving a 20% reduction in roadway construction costs. Any civil engineer can tell you there is huge savings available if a stormwater system can be downsized or eliminated altogether.
The Street as Art
Residents in Portland, Oregon, tired of speeding traffic, began organizing with their neighbors to paint giant murals in the middle of speed-prone residential intersections. These colorful displays not only cause drivers to ease off the gas pedal, but they reduce the tendency to speed once neighbors know each other. The city, at first opposed these artistic endeavors, is now supporting these community initiatives to slow traffic. Other cities have installed sculptures, or entire sculpture gardens, on underused pavement.
“Depaving” – Another Portland First
Another Portland innovation is “depaving” – organizing large groups to break up and haul away pavement to make room for parks, gardens, or other green uses. Based on the economics alone, this makes a great deal of sense. Real estate next to a park is far more valuable than that next to a large road or parking lot. And recent studies show that health, mental health, physical activity levels, and life span all improve when residents have green open space nearby.
New York – A Different City through Street Reclaiming
The champion for street reclaiming has to be New York City. Most planners have heard about New York’s many efforts to calm streets, install a network of “cycle tracks” (bike lanes nestled between the curb and parking lane), fix pedestrian danger “hot spots,” and convert parts of intersections and entire streets to public plazas. What they may not realize is that these projects evolved in concert with an unconventional new Street Design Policy.
- Move people and goods safely.
- Accommodate all street users, giving priority to the most energy- and space-efficient modes.
- Respond to neighborhood character.
- Create a vibrant public realm with high-quality public spaces.
- Contribute to a healthier and more sustainable environment.
- Create coherent and harmonious streetscapes.
- Provide the greatest possible value to the public.
Note the emphasis on design, protecting vulnerable users and returning value. Also notice also there is nothing about adequate parking, congestion relief, or Level of Service. After attending the International Walking Conference in New York last October, I was amazed at what’s been accomplished and how the Street Design Policy has made New York feel even more vibrant than ever before. Sure, New York has an amazing transit system, but much of what they’re learning could apply anywhere. Only later did I learn these changes were pushed through by a new Transportation Commissioner who, evidently, is not an engineer. I believe this is key. Engineers are great at what they do, but we shouldn’t expect them to be the visionaries. That’s not (usually) their thing.
University Avenue Demonstration Project
So where do we start? Cities, such as Copenhagen, that have dramatically transformed their streets began, not with a grand plan, but with small demonstration projects. Downtown San Diego could certainly experiment with a couple of streets. In the same way, a planned redesign of University Avenue in North Park could be the real catalyst we need.
The neighborhood’s Main Street organization worked with consultant KTU+A, City of San Diego staff and SANDAG to devise an innovative plan that dedicates two of the four lanes to buses, provides medians prohibiting dangerous left turns, and includes landscaped curb extensions and in-pavement flashing crosswalks at numerous locations. Left and right turn pockets will help traffic flow smoother and more safely, while the single lane each direction will let the prudent driver set the speed. If the scheme works, look for residents around the region to demand something similar. Until then, planners can be looking at the massive investment in their own community’s streets and asking how we can serve the public better by squeezing more value and more life from this amazing resource.