
The evaluation of the three general models of Chacoan road function suggest
that the roads did not function to economically integrate the region. With
the notable exception of the South Road between Chaco Canyon and Hosta Butte,
none of the road segments in the study area extend more than a kilometer
or two, and virtually none fall even close to cost-paths that minimize travel
time between communities. In contrast, almost all roads appear to fit more
closely with explanations that see the roads as having served localized
religious, integrative, and/or political functions (Figure
11).
Distinguishing between religious and integrative/political explanations
of road function is more difficult. In a few cases, roads fit the expectations
of both models. For example, one road segment in Andrews connects the Great
House with a nearby cluster of habitations that also includes a Great Kiva
(Figure 5), thereby meeting the expectations of
both the religious and integrative models. More than likely, an improved
model of road function will combine aspects of both complementary interpretations.
Was the GIS necessary to effectively perform this study? Clearly, the various
models of road function would have been much more difficult to evaluate
without the GIS' ability to generate cost-paths. This is especially true
since the roads consisted only of short segments. At the same time, the
GIS facilitated the identification of other unexpected patterns that also
contribute to the issue of road function and intercommunity interaction
in the northern Southwest.
An important issue that needs to be addressed, however, is the best way
to evaluate the fit between the idealized cost-paths and the actual road
segments. One potential method is through the use of concentric gradients
representing movement away from the point of origin. For example, the grayscale
backgrounds in Figures 4 and 7
represent gradients away from communities, allowing for a qualitative sensitivity
analysis. In Figure 7, the road that appears to
extend from Kin Ya'a to Hosta Butte at one point veers away from the idealized
cost-path, but the gradient of movement costs away from the community shows
that the cost to follow the road was actually very similar to the cost to
follow the cost-path. Further research should be invested in methods to
more objectively evaluate the fit between modeled paths and the actual prehistoric
roads.
Despite the potential for improving the models and methods used in this
study, the results do provide a useful evaluation of the function of prehistoric
roads used by the Chaco Anasazi. Few roads seem to have been oriented towards
regional interaction, with most apparently constructed to serve localized
functions. This suggests that the mere presence of roads segments should
not serve as a way to determine either the spatial extent of Chaco Canyon's
authority or the intensity of large-scale travel and exchange in the region.
Perhaps roads were actually a general Anasazi phenomenon that Chaco Canyon
manifested at a larger scale through the construction of a few longer roads
such as the North and South Roads. Meanwhile, the majority of communities
in the northern Southwest continued to construct short roadways for their
own purposes.
