Forecasting the Future

How to use multiple projections to positively shape regional growth

Urbanist Article September 1, 1999

The Regional Transportation Plan

One of the primary functions of the Metropolitan Transportation Commission (MTC) is to distribute federal, state and regional transportation funding to local jurisdictions in the Bay Area. The primary tool used by MTC for allocating this funding is the Regional Transportation Plan (RTP). The RTP programs virtually all the region's transportation expenditures for 20 years into the future, with updates every two years. The RTP was last updated in 1998.

An enormous amount of work goes into developing this plan. MTC has the job of integrating the wishes of all nine Bay Area counties into one coherent package. MTC must also say "no" to a lot of projects so that the total budget for the RTP equals the amount of money the region can expect to receive.

The problem is that, according to MTC's own modeling, the region will be much worse off in 20 years if we follow the official RTP. They show congestion, time spent travelling, pollution, and sprawl all getting worse. The RTP, in fact, simply organizes in one place the cumulative effects of all projects which were put into past RTPs, along with the priorities of local jurisdictions. In this way, the region becomes the victim of its own past, seemingly locked into a future path which was ordained long ago.

We need a regional transportation plan that presents us with meaningful alternatives. (Although the RTP contains several "alternatives," they are only slightly different versions of the same basic priorities, with less than 10% of the expenditures varying between alternatives.)

Imagine for a moment what would happen if MTC prepared three different RTP options: the Status Quo Option, which projects that future trends will continue; a Car-Centered Option, which projects the bulk of investments being made in roads and a regional mode shift towards greater driving; and a Sustainable Option, which projects a shift towards greater land use densities and a substantial increase in the percentage of funds spent on public transit. Each of these three options would be funding-constrained, relying on the same amount of money over the next 20 years. The plan would map out the choices and spending priorities that would lead to each option.

In this planning fantasy, regional decision-makers would be confronted with a tough set of decisions. There is no guarantee that they would make the right choice. But the powerful tool of forecasting the future would be used to clarify the long-term consequences of our choices. The public could be involved in the ensuing policy debates. And we might be capable of making some of the hard choices, which today we are not even forced to consciously view as choices at all.

The Alternative Regional Transportation Plan

In one of the most under-reported regional stories of the decade, a group of planners and environmentalists working under the umbrella of the Regional Alliance for Transit (RAFT) modeled something like the "Sustainable Option" for the 1994 RTP. They used ABAG's 2010 population projections just like the official MTC plan and they used the same funding total as MTC, but they wanted to test what would happen if growth were clustered around transit and more funding was directed into alternatives to the automobile. To carry out this experiment, MTC staff agreed to run the "RAFT projections" through MTC's own modeling program.

RAFT proposed three changes to the assumptions of the official Regional Transportation Plan:

*A large portion of new growth would be clustered around transit.

*Employers would offer "parking cash-out," i.e., employees who receive free parking would be offered the option of receiving the equivalent value in cash. In addition, RAFT assumed that places such as shopping centers would begin to charge for parking.

*Funds would be shifted from highway enhancements to transit. This included de-funding several major highway projects which had already been promised funding by MTC, but which had not yet been built, and instead funding several transit projects that have sat on the shelf for years.

The results of modeling this alternative regional plan are contained in the tables below. It would have saved open space (approximately 150 square miles), reduced auto ownership (3%), and reduced average time spent travelling (42 hours per year per family). See the tables for more specifics on the model's results.

MTC says that they lack the authority to carry out a plan like the RAFT alternative. They are forced to respond to local desires, which favor more sprawl and auto-oriented growth. In many ways, MTC is correct. They do not have any powers over local land use. But two counter-arguments need to be made. First, MTC could use its control of the purse strings to establish incentives for transit-supportive land use. Local jurisdictions which move towards greater densities would be rewarded with a greater share of the regional money. Second, if MTC were to model true alternative futures, they would at least let the citizens of the Bay Area understand the choices before us. If the region were shown more clearly what was at stake, perhaps people might even begin to think seriously about giving MTC the powers it currently lacks.

Growth Projections

The Association of Bay Area Governments (ABAG), also has the job of predicting the future. Every other year, ABAG issues a "Projections" report which presents predictions for job and population growth the next several decades.

ABAG is respected for its methodological rigor. They interpret the land use plans from all local jurisdictions, integrate this with projected regional growth, and then try to predict where in the region growth is likely to take place.

The problem lies in the uses to which ABAG's forecasts are put. Officially, they are used to allocate federal and state funds for sewage treatment and transportation investments; to help local congestion management agencies develop congestion management plans; and by the Air District to estimate future pollution.

But unofficially, ABAG's projections are used by local jurisdictions as a guide to how much growth needs to be accommodated. ABAG tells San Francisco that by the year 2020, the city will contain 27,500 new households. San Francisco policymakers, therefore, wanting to be "in line" with this projection, must make sure we plan for that number of new units. The problem is that ABAG's initial projection of household growth is itself nothing more than an extrapolation of already existing local plans. In other words, if current plans are realized, almost half a million new households will be built in the suburban periphery by 2020, and San Francisco will only growth by 27,500 households. But we should be doing everything in our power to make sure this scenario-the cumulative total of existing land use plans-is changed. We should try to channel the region's projected growth into existing cities instead of the auto-dependent periphery.

ABAG's growth projections are treated as inevitable. Their reports sometimes talk passionately about the negative consequences that continued sprawl will have for the region: open space will disappear, more people will be forced to drive more often, congestion will get worse, and housing will get more expensive. ABAG is quite aware of the limitations of their projections. (See especially and "Where Do We Live and Work?" and "Trends and Challenges," two reports which raise many of these very issues.) But ABAG's projections, like MTC's Regional Transportation Plan, show only one official future.

In fact, there are multiple possible paths they Bay Area could follow. The total growth of population and jobs for the region is something that can be predicted (although it should probably be presented as a range). However the way we accommodate that growth is something that we have choice over. Sprawl or density, center or periphery, mixed-use or single-use-these forms of growth are largely dependent on the choices we make as citizens.

The ABAG projections should be viewed not as inevitable trends we must "get in line with," but as the dire path we are now walking down, which we must do everything in our power to change. What we need is not one set of "projections," but alternative futures we can choose between.

In every community in the Bay Area, a struggle is going on between advocates of pedestrian- and transit-oriented development, and NIMBY-style groups who want to push development "out of sight, out of mind." The form of the Bay Area in 20 years will be the culmination of all of these battles. Our future will be the outcome of the choices we make today. The discipline of planning should clarify for all citizens what the decisions we make today will lead to in the future.Spur logo

About the Authors: 

Gabriel Metcalf is SPUR's program director.

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