The first step is a survey of visual preferences. While such an evaluation is subjective, it provides insight into commonly held perceptions and values regarding the visual qualities of the landscape. To determine whether or not personal experience altered visual preferences, two experiments were conducted: a "geographic study" and a "training study" (Bales and Blomberg, 1996). In the geographic study, eighteen persons from California and sixteen from New England were interviewed to test if Californians, whose experience, perceptions, and values of the landscape were formed in the study area, had significantly different preferences than those from outside the region. In the training study eleven Harvard Graduate School of Design students and twenty-three non-students were interviewed in order to test the difference in preferences of people who have been trained to be perceptive of their visual environments and those who have not.
Preferences were determined by using a set of 26 photographs of the study area which represent the range of land cover types in the region. Participants were asked to arrange the 13cm by 18cm color photographs into five numbered piles ranging from 1 (Most Preferred) to 5 (Least Preferred). There was no required maximum or minimum number of photographs in each pile. The participants were given as much time as they felt necessary for the task. They were permitted to change the location of any photograph until they were satisfied with its location.
Average values were then charted by sub-sample and also in the aggregate. The results of the study showed that there were no significant variations in the landscape preferences of the different groups. Significant variations were defined as a change of more than one set on the chart. Figure 92 shows the twenty-six photographs grouped by aggregate average value range, from "Most Preferred" to "Least Preferred."
The survey photo characteristics were then described in GIS land cover categories. A map of the 1990+ pattern of visual preference is shown in figure 93. This pattern will change considerably as a result of Plans Build-Out. Exposure was defined in terms of whether areas were visible in the foreground, middleground, or background, or not visible, from all the major transportation routes in the study areas. The Exposure Pattern for 1990+ is shown in figure 94.
Preference and exposure were combined to define the value of preferred landscapes. For example, areas that were in the most-preferred class and were also the most exposed were assumed the most valuable to protect. At the opposite extreme, areas which were least preferred and least exposed are where maximum change might take place. If the study region's many jurisdictions would adopt policies that would manage the region's most valuable visual qualities (and Plans Build-Out does not assume this) then the locations which might adopt the five policy levels of preservation, retention, partial retention, modification, and maximum modification in 1990+ are shown in figure 95.
Because of the absence of such policies, there will be significant impacts on many of the region's most visually preferred and exposed landscapes caused by Plans Build-Out. These are shown in figure 96.
One consequence of this projected pattern of visual change is that highly scenic roads will become quite rare in the region. One such scenic road is the Ortega Highway, Route-74, which runs east-west through the Cleveland National Forest. Because of increased traffic demand generated by urban growth in the Temecula Valley, there will be pressure to expand capacity. Some proposals with this aim have already been made. While there may be traffic benefits derived from widening this road or building new roads, the visual consequences are likely to be negative. More importantly, the region's single largest contiguous habitat zone would be split by a wider expanse of concrete and macadam. This would be a threatening circumstance for biodiversity.