Since the 1970s, archaeologists investigating the Chaco Anasazi have tended to see the prehistoric roads in the northern Southwest as having served an economic function (Ebert and Hitchock 1980; Judge 1984; Kane 1993; Mathien 1991; Powers 1984; Wilcox 1993; Windes 1991). These theories are stimulated by the fact that the roads appear to begin in Chaco Canyon and extend over the San Juan Basin. Economic explanations are often rooted in general theories of Chaco Anasazi development that see the system evolving in order to contend with spatially heterogenous resource availability. For example, some scholars argue that Chaco Canyon served as a central point for redistributing commodities from areas of temporarily high production to those communities experiencing subsistence stress (e.g., Judge 1984; Powers et al. 1983; Tainter and Plog 1994). According to this view, roads expedited transportation across the Chaco system. This conclusion has provided the foundation for a variety of studies employing geographic models to reconstruct the economic and political structure of the Chaco Anasazi (e.g., Ebert and Hitchcock 1980; Schelberg 1982; Wilcox 1993; Winter 1980).

Recent investigations have challenged economic explanations for the road system. Much of this criticism is based on ground surveys that have attempted to verify the presence and antiquity of roads identified through air reconnaissance (Kincaid 1983; Nials et al. 1987). Many of the roads that were once thought to connect communities now appear to have huge gaps in them; in fact, few roads actually extend more than a kilometer or two beyond their point of origin (Roney 1992). However, in many cases it is also clear that natural forces such as erosion or alluviation could have removed or buried many prehistoric road fragments.

For this study, the general economic model of road function was evaluated by determining how closely the road segments followed cost-paths between communities. The results were fairly unequivocal: virtually none of the road segments in the study area came even close to aligning with idealized cost-paths. Figure 4 illustrates this quite clearly. Dotted lines represent cost-paths between the community of Muddy Water and every other community in the study area. The prehistoric road does not align with any of these projected routes, suggesting that the road was not constructed to facilitate economic interaction with nearby communities. The other illustrations on this poster demonstrate similar patterns.

There are only two road fragments that may fit the economic model for road function. The first is the famous South Road that originates in Chaco Canyon itself and enters Kin Ya'a (Figure 2) (Nials et al. 1987:18-19). This may have served a regional economic role, but because it extends out of the study area its alignment with potential cost-paths could not be evaluated. The second road fragment that may fit the economic model is a small segment of road that is the only one not associated with an Anasazi community, although it is found in a small "hamlet" consisting of a few habitations. This particular fragment aligns with cost-paths between several communities. Whether this is coincidental is difficult to surmise, but the poor fit between all the other road segments and intercommunity cost-paths suggests that it may be.

The evidence from this study demonstrates that Chacoan roads do not fit well with economic explanations based on regional interaction. However, while these roads may not have served to facilitate intercommunity exchange, at least one may have served a more local economic role. A road segment originating in Muddy Water leads to the cliffs at the base of Lobo Mesa where a spring is believed to have once existed. Archaeologists investigating this road identified numerous pot fragments along the road and suggested that these vessels were used to obtain water from the spring (Nials et al. 1987:140-141). Similar local economic functions have also been proposed for other road segments in the San Juan Basin (e.g., Windes 1991:120-122).