July 27, 2023
The word "unprecedented" has been used so often to describe everything from the weather to public health in recent years that it seems the only certainty is uncertainty. This makes the job of urban planners especially difficult as they try to anticipate what their cities will need in the decades to come.
Robert Goodspeed, AICP, is a planner and associate professor at the University of Michigan's Taubman College of Architecture and Urban Planning. He is also the author of Scenario Planning for Cities and Regions: Managing and Envisioning Uncertain Futures, published by the Lincoln Institute of Land Policy in 2020.
"The argument for the use of scenarios is that the momentum of current trends becomes more and more uncertain as you roll forward ten, 20 years," he explains. "A lot of exploratory scenario planning adoption has been in domains of planning that are trying to make decisions and create plans that speak to the 20- or 30-year horizon."
Goodspeed joined APA Research Manager Joe DeAngelis, AICP, for a special APA Podcast episode to talk about how exploratory scenario planning (XSP) can help city planners build robust plans to prepare for whatever comes next — be it rain, shine, boom, or bust.
This interview has been edited for length and clarity, but you can listen to the whole conversation at planning.org/podcast or wherever you get your podcasts.
DEANGELIS: For those of us who are new to scenario planning, give us a brief description of what it is and its roots in the planning field.
GOODSPEED: The whole idea of scenario planning is that you should prepare plans through the creation of multiple alternative, future scenarios. It's a family of related methods. There are different flavors of it — quantitative and qualitative — that have been developed by planners and others.
The whole idea of scenario planning is that you should prepare plans through the creation of multiple alternative, future scenarios. It's a family of related methods.
A jumping off point to understand the roots of XSP is the idea of participatory community visioning, which has been a big thread ever since Daniel Burnham's Plan of Chicago and continued through the 1980s and '90s.The problem with that methodology is that it wasn't very rigorous or specific; everyone kind of agreed to a vague vision. Then, the movement towards new urbanism — also called smart growth scenarios or visioning 2.0 — comes into the toolkit as a more rigorous way of defining possible futures, including a trend scenario. You create alternative land-use scenarios and then essentially decide which people like most, then use that as a roadmap.
Then, there's another perspective where the planning begins with a forecast — for population, for traffic, for whatever resource demand it is — and we work backwards and figure out the infrastructure we need. And so, what's the problem with that? No one can forecast — they're often wildly inaccurate.
DEANGELIS: Then comes exploratory scenario planning, with its origins in geopolitical decision-making and the business world, right?
GOODSPEED: One key source is Herman Kahn — the inspiration for Dr. Strangelove — and wargaming nuclear war scenarios. But the method really has been developed by corporate strategic planners, especially at the Shell Oil Company. They have to make huge bets that are very sensitive to things they don't control, like the price of oil, the price of energy, and so forth. And those methods have been the inspiration for folks in planning like Uri Avin, FAICP, a longtime practitioner I collaborate with and who read that literature and said, "We can't just take the textbook and plop it down in planning, but we can be inspired by it. We need to translate it."
The methods are based on an open-ended, qualitative exercise of conducting research and brainstorming about the forces that are going to shape the future of what we're planning. In the planning field, this has become known as exploratory scenario planning, or XSP.
The flavors of planning I was describing earlier probably feel very comfortable for planners, but the obvious weakness of just tweaking our frameworks is that you have these amazing land-use scenarios that don't account for broader issues like shifting housing preferences, climate change, and equity. Exploratory scenario planning has the power to bring in these outside factors that aren't really part of the very narrow, domain-specific planning tools. But when we realize they're our blind spots, we can't ignore them anymore.
Exploratory scenario planning has the power to bring in these outside factors that aren't really part of the very narrow, domain-specific planning tools. But when we realize they're our blind spots, we can't ignore them anymore.
The most recent project that I've been really inspired by is the regional transportation plan Plan Bay Area 2050, which used an exploratory activity called Horizon to generate the strategies and ideas that went into their plan. It's a very sophisticated melding of the more exploratory and normative elements.
DEANGELIS: What might success look like at the local level, where it's not as reliant on in-depth modeling of the future?
GOODSPEED: One example that I think is kind of inspiring is Madison, Wisconsin, where they realized they were happy with the general pattern of land use, but they weren't sure about where to foster growth with infrastructure subsidies to create growth nodes: redevelopment in the urban core, or more growth at the periphery of the city? They used Urban Footprint as part of their comprehensive plan. And from there, they looked at the trade-offs, and they created a map where they proactively identified some growth nodes and tried to use that for planning their BRT and other activities across the state.
Planners will find that, yes, maybe XSP is a little more expensive; there's an adoption cost. It's a little bit more open-ended. Technocratic planning is very streamlined because, it turns out, not talking to people really simplifies things. But I've heard some feedback that the plans informed by XSP have a longer shelf life and greater impact.
DEANGELIS: You've discussed XSP for transportation planning and urban growth management. Is there something about these fields that makes scenario planning a better fit?
GOODSPEED: One thing to consider about when and where to use scenarios is the time horizon of the project. If it's a really short term, then the current trends are probably going to be dominant. The momentum of current trends becomes more and more uncertain as you roll forward ten, 20 years. A lot of XSP adoption has been in domains of planning that are trying to make decisions and create plans that speak to the 20- or 30-year horizon. That's the horizon of transportation, land use, and water supply by practice. But I think there's absolutely a lot of opportunity in different planning domains.
I feel like there's no one right type of scenario planning. It's very context dependent. Some communities are realizing they've got narrow mandates — create a housing production plan, do a land-use plan — but the bigger picture is the community is changing, and it's facing a lot of challenges, be it economic, climate, whatever. And there's a desire to have a framework to study those and think about them in a systematic way that makes it manageable and allows different city departments to get on the same page and talk to one another. That's exactly the strength of XSP.
I feel like there's no one right type of scenario planning. It's very context dependent. . . . That's exactly the strength of XSP.
DEANGELIS: What about something like hazard mitigation planning? Hazard mitigation plans are on a five-year update cycle, so it's slightly more difficult to have a long-term outlook, even though the impacts of natural hazards are long-term. Can scenario planning bring any utility to hazard mitigation or climate adaptation?
GOODSPEED: Absolutely. One impetus to be more exploratory in a lot of these plans is the desire to bring climate change into the planning process. In the IPCC world (the Intergovernmental Panel on Climate Change, the United Nations body that monitors the science around climate change), a scenario is about a degree of atmospheric forcing and warming, and the impact from that model climate scenario is the uncertainty.
Climate change people are saying, "Oh, it's terrible, and I can read to you the list of impacts," but then you're still building in the floodplain, and your engineering assumptions for your roadways don't accommodate the rain intensity that the modeler knows about. And I think you can hear through that example the whole value of scenarios is the framework to combine the topics and connect traditionally siloed activities.
DEANGELIS: What does the future look like for scenario planning as a field in itself?
GOODSPEED: There's been a lot of interest in bringing in equity in scenario planning. I'm deeply involved in a project to map racially restrictive covenants, create a zoning atlas, and look at both through the lens of racial equity and inclusion. Sometimes equity is just a lens for seeing more technical indicators, but it's also about the framing of problems: Who's included, and how can the plan be used to scrutinize and challenge institutions and the assumptions that they're based on?
I wrote a whole chapter in my book about racial equity because in a lot of cities there's an interest in interrogating racial inequity in different planning-related, institutional structures: zoning, land use, the siting of transportation infrastructure, even the priorities of whether we invest in freeways or transit.
I also think there's a lot of interest in market-based solutions within the planning field. I think what we're going to discover is zoning is very important, but there's a lot of other factors that shape housing. I think we're going to need to plan for transformation in a more robust way. And I think there's room for scenarios.