In the 1^st century BC, Dionysius of Halicarnassus opined that “the three most magnificent works of Rome, in which the greatness of her empire is best seen, are the aqueducts, the paved roads, and the construction of the sewers”. [1] This sentiment was echoed by Strabo (1^st century AD) and has continued into the modern era. [2] Although unintended, Dionysius’ enumeration is also organized by scholarly interest. The ancient aqueducts and roads of Rome have long been an object of practical fascination. [3] Only recently, however, have issues of sanitation been considered as worthy subjects of inquiry in their own right. [4] As interesting as these elements are on their own, it only reassembled in their totality which fully reveals their role in the ancient Roman life and does justice to the assertion of Dionysius. While these subjects are studied independently, Rome was not the sum of its parts. Rather, it was an indivisible whole, which, in order to be understood as such, must be studied as such.

Therefore, in this paper I endeavor to contribute to the study of Roman urbanism by examining the systems of water and traffic as interlocking elements in the infrastructure of a Roman town. The interdependency of these systems will be shown through the impact that changes to Pompeii’s architecture of the water supply and drainage have upon the organization of its traffic. The streets retain most evidence of this necessary connection, and therefore are the main source of information. The nature of this link is examined first at its most basic level, showing the role the streets played in the drainage of wastewater. The connection is then explored more deeply through a discussion of the use of water system architecture to impede or improve access to vehicles. While these individual uses begin to unveil the degree of integration in planning for both systems, case studies of an entire street or a whole region of the city illuminate the scope and complexity of the urban design and its operation. Finally, I will conclude with some remarks on the significance that this study and others like it have in our understanding of how the ancient city works.

The method of studying water systems through their architecture, such as fountains, drains, and water towers, is relatively well understood. Ascertaining the organization of traffic from archaeological evidence, however, is not. Although I have presented the on directionality of traffic at previous meetings of the AIA in 2001 (San Diego) and (New Orleans) 2003, a brief introduction seems required to make this methodology transparent. [5] When examined thoroughly, curbstones, stepping-stones, and other street features disclose a wealth of evidence diagnostic of the direction of cart travel. For example, cart wheels often overrode stepping-stones to create a wear diagnostic of direction (Figure 1). Likewise, successive collisions with the curbstones produced equally revealing erosional patterns (Figure 2). Coincidentally, the high curbs and stepping-stones on which this evidence is found exist only because of the role of the streets played in the drainage of Pompeii. The connection of wheels and water is as fundamental to their study as it was to their existence!

On Vico della Maschera (Figure 3) this association can be seen quite literally. Cut through the eastern curb, a well-made drain issues out to the paving stones from under the doorway of a small shop (Figure 4). Crossing this sluice is a led pipe, which supplied water to both the fountain at the north end of Maschera (Figure 5) and a large house at its south end (Figure 6). This image is a kind of microcosm, nicely encapsulating an important fact of the larger civic infrastructure. Namely, that the architecture of supply- such as the fountain, the pipe, or the water tower which pressurize them (Figure 7) – and the architecture of removal - the canalization, cambered pavements, and blockages (Figure 8) – both influence the design of the urban streets and effect the circulation of traffic.

In her chapter of the recent publication, Sordis Urbis, Gemma Jansen outlined the essential role that streets played in the drainage of Pompeii. [6] Compared to other cities, such as Ostia or Herculaneum, Pompeii had few underground sewers. Instead, the streets carried wastewater out of the city or to the rare public drain. Via dell’Abbondanza offers an archetypical example. Beginning with its western terminus at the Forum, Abbondanza slopes down towards its intersection with Via Stabiana. Along the way, every cross street from the south is ramped upward slightly to prevent the influx of water. Excluded from these streets, the water was funneled to a large drain beneath the new pavements near the Stabian Baths (Figure 9). Across Via Stabiana, the canalization of Via dell’Abbondanza is even more conspicuous and significant (Figure 10). On the eastern portion of this main thoroughfare, many more streets are ramped upward at an even steeper angle, including those intersecting from the north (Figure 11). These blockages channeled water out of the Sarno gate and prevented it from inundating the residential areas of Regions I and II. At the same time, they were also designed to permit access to wheeled vehicles, as proven by ruts found on some of the ramps. [7] At a few other important intersections, however, the curbstones simply continue unbroken, denying both water and wheels.

An example of the latter at Vicolo di Paquius Proculus and Via dell’Abbondanza is made particularly interesting by the added presence of a water tower that also made the Vicolo impassible (Figure 12). Proof that previous traffic on Vicolo di Paquius Proculus was suppressed is found in the curbstones. Large limestone slabs make up the south curb on either side of the intersection except for two lava blocks set to act as cornerstones of the former street. Large stones of irregular shape and a different volcanic material seal the once open space. [8] The blockage, therefore, was designed as much to deter traffic and protect the water tower as it was to canalize the street. Furthermore, in narrowing the side street beyond use, the water tower’s placement reveals a power relationship between two infrastructural systems competing for the same space.

Without doubt, the unfinished Central Baths were the most conspicuous example of traffic being altered by an element in the water supply system (Figure 13). Conceived on an imperial scale within a provincial setting, these baths suppressed two streets completely. The closure of the northernmost block of Vico di Tesmo and the eastern segment of Vico di Panettiere disrupted the previous pattern of traffic across the entire central region of the city (Figure 14). Perhaps it is unfair to compare the value of two small side streets with a colossal construction like the Central Baths. Nonetheless, the juxtaposition shows two systems jostling, quite literally, for position. In human terms, the suppression of the streets spotlights the urban designers’ decision-making process, even if in this case the decision was a no-brainer.

Compromise, on the other hand, requires a far greater concern for the uninterrupted flow of both water and wheels. When the Forum baths were constructed early in the 1^st century BC, the associated water tower was recessed into the west side of the building (Figure 15). This concession allowed for traffic to pass unimpeded along the Vico delle Terme. Similarly, the water tower that fed the Central baths was also erected outside the right of way. Along with the associated fountain, this tower occupies space within a pedestrian piazza where Via Vesuvio meets Via della Fortuna (Figure 16). Only the stepping-stones were obstacles at this major intersection, and even they were positioned to facilitate both crossing foot traffic and turning carts (Figure 17). Even these few examples of compromise demonstrate that those in charge of managing the water supply system were hardly indifferent to the circulation of vehicles. As we will see, they likely worked closely with those administering the traffic system. [9]  

Some might argue, however, that the instances described so far are merely ad hoc decisions concerning only the construction at hand and only the surrounding streets. This opinion sells the Pompeians short. In the first place, one does not simply ‘plop down’ a fountain, water tower, or bath complex. Appropriate pipes must be run along the streets to the fountains, the height of the tower must be calculated to the pressure in the pipe, and previously owned land must be obtained and cleared to name only a few organizational issues. Additionally, the suppression of a street had ripple effects across the surrounding areas, as cart drivers were forced to choose alternate routes. These detours changed the volume traffic or even caused the direction of travel to be reversed. Like blood in the body, no operation on the water or traffic system could myopically dismiss consideration of the disruption of life which that operation might cause within the entire city.

The ancient Pompeians, however, were capable civil engineers and the extent of their planning is embodied in the complexity of the physical remains. The positions of the fountains on Via della Scuole and Vico del Gallo express the specific functions they were intended to play within the overall urban form. Like other components of the water supply system, these fountains also bar traffic from a street. However, in these instances the function of supplying water is subservient to that of blocking traffic. The need for these blockages is itself an effect of some large-scale alteration of the urban fabric.

The first such alteration is the expansion of the Sanctuary of the Temple of Apollo (Figure 18). The 1997 excavations by the Pompeii Forum Project have dated this rebuilding to the Augustan age and shown that the new western precinct wall almost completely occupies the space of a former street (Figure 19). [10] Farther north, this precinct wall cuts through the Vico del Gallo, narrowing the street to approximately 1.45m; too narrow for even the smallest carts. [11] Vico del Gallo’s northern intersection with Via dei Soprastanti is blocked by what remains of a continuous line of curbstones. Reminiscent of the impermeable blockage at Vicolo di Paquius Proculus, the stones filling this gap are markedly different from the flanking curbs.

More importantly, however, is the obstruction produced by the eponymous fountain at Vico del Gallo’s western intersection (Figure 20). Here the evidence for traffic is both strong and diagnostic of direction. The southeast corner curbstone preserves a deep wear from carts making north to east turns (Figure 21). The overriding wear on the stepping-stone, being stronger on its south side, also supports this northerly direction (Figure 22). The placement of the fountain, which is itself unworn, prevented turns by reducing street width to under a meter. Thus, because Vico del Gallo was made impassible near the middle of its length by the expansion of the Apollo Sanctuary became necessary to keep vehicles out of these two now dead-end streets. [12]

Across the Forum (Figure 23), where Via delle Scuole meets the city center, another fountain operates as a closure to wheeled vehicles. This impasse is part of a major, unified campaign by the Pompeians to monumentalize the Forum and make it a pedestrian zone. Within this program, the fountain is one of the least disruptive methods of closure, especially when compared to the monumental structures on the east side of the Forum, which overbuilt Vico degli Scheletri and Vico del Balcone Pensile. [13] Similarly, the construction of the south buildings put two other unnamed streets out of use (Figure 24), while the Basilica intruded upon Vico di Championnet. The changes in the west caused by renovation of the Sanctuary of Apollo have already been discussed. In the north, access is denied by two flights of stairs and a set of standing stones. Once all these projects were completed, carts were banished from the monumentalized heart of the ancient city.

Close scrutiny of the Via delle Scuole (Figure 25) fountain demonstrates that its placement was more than an ad hoc solution put in place for want of another ornamental building (Figure 26). First, Via della Scuole was an important artery of traffic for Regio VIII. In fact, the fountain is cut into a ramp that allowed cart traffic even after the southern stylobate had been laid. [14] What’s more, the east side of the fountain is itself worn by southbound carts. Only the addition of the guard stones finally prevented the passage of vehicles.  Northbound traffic was also using the street as shown by the diagnostic wear on the corner curbstone at the south end of Via della Scuole demonstrating a west to north turn. The fountain at this same intersection is also of great interest since it is recessed into the curb to permit easier access.

As part of the greater design of the Forum, the primary function of the Via delle Scuole fountain was to impede traffic (Figure 27). Indeed, the goal of supplying water seems redundant due to the proximity of the fountain at the south end of the street, further highlighting its role as a traffic stop. [15] In fact, another fountain at the northwest entrance to the Forum does not function as a blockage due to the steep difference in elevation between the street and the Forum. The contrast shows that when not required to function as a blockage, fountains were positioned with concern for other logistical needs, such as the use and removal of their overflow. Indeed, the runoff from this northern fountain is used to flush the Forum toilets, which are themselves tied to one of two massive drain systems at the Forum.

Another system drains the entire south end of the Forum area, including the rainwater inside the Forum, the constant overflow from the two fountains on Via della Scuole, and the wastewater from the surrounding insulae. The great travertine surface of the Forum was drained by nine sluices cut into the southern stereobate. Wastewater from the south drains down into the same system through an opening in the northwest corner of Via della Scuole (Figure 28). The planning at this intersection is so detailed that the overflow hole and sluice in the fountain opens directly towards this drain (Figure 29). Pulling back to take an overview of all the evidence, we can see the designers closely calculating the position of the fountains with reference to both the lines of supply and schemes of drainage, as well as considering the desired result for the circulation of traffic.  

It is important to analyze even larger sections of the city, not bound to an individual infrastructural project, in this way. This is because a regional approach cuts across the city to include multiple projects with distinct purposes and effects on the urban fabric. Moreover, the harmonious interplay of these separate elements of infrastructure illustrates integration in planning far broader than the specific effect of the element itself. The regional view begins to re-totalize these individual pieces into the full picture of a functioning whole, illuminating how the city worked while still spotlighting the individual decisions taken to make the city work. Then, once the operation of an area of the city is understood, more subtle ideas about the character of that area can be considered.

The area of Region VII “behind” the Forum has been of particular interest in the last decade of Pompeian studies (Figure 30). Believing that it was possible to "see Roman ideology inscribed on the ground, down to the very wheel - ruts in the paving stones", Andrew Wallace-Hadrill used this Region in an attempt to define the moral geography of Pompeii. [16] In brief, Wallace-Hadrill characterized this area as an isolated section of vice bounded by a boulevard of virtue. His archaeological evidence boiled down to the prevalence of brothels along the narrow alleys as compared to the absence of even drinking establishments along the broad, rutless route of Via dell’Abbondanza. Translating his evidence into human terms, Wallace-Hadrill’s argument lies in the contrast of deliberate control of traffic on Abbondanza with the “dark places that fear the aedile” behind the Forum. Another attempt to ‘read’ the ‘urban texture’ by Ray Lawrence likewise used the character of the streets behind the Forum. His conclusions, however, were radically different, claiming this area was the “integrating core of the city”, a kind of urban centrifuge, which spiraled travelers out into the more rigid, less distributive street grids.

Examining this same area for the movement of vehicles as well as for the effects of the supply and removal of water produces yet another set of conclusions about the area behind the Forum. The most immediate and important result of this research demonstrates that this region was nearly a closed system within the larger pattern of traffic. Access from the east and south was only permitted via a detour onto Via del Tempio d’Iside, then northbound on Via dei Teatri. Moving northward on Via Stabiana, access was denied by the raised pavement and drain on Via dell’Abbondanza (Figure 31). The next intersection with Via degli Augustali is open to traffic, but not to westbound vehicles. Here a large brick water tower and the eastern half of a stepping-stone detoured south to west turns. Evidence for such a turn is absent, but an east-to-south turn is suggested by the wear on the westernmost stepping-stone (Figure 32). The final intersection at Vico del Panettiere, whose eastern extension (IX.4 / IX.3) was suppressed by the central baths, also only shows evidence of a right-hand, east to south turn. The only street in the north, Vicolo Storto, exits it northbound traffic onto Via della Fortuna. Finally, from the west, Via degli Augustali offers entrance into this region, but only as a through-route. The evidence for turns at the intersection with Vicolo Storto and Vico di Eumachia shows a high volume of traffic but no evidence of west to south turns (Figure 33). Moreover, the only other intersection, at Vico del Lupanare, is closed by a large water blockage (Figure 34), leading us right out again to Via Stabiana.

With only two difficult routes in, this section of the city does not support Ray Laurence’s idea of an integrating core. Similarly, the large degree of traffic control in this area contradicts the contrast Wallace-Hadrill made with the orderly, and thus civilized, Via dell’Abbondanza. The lack of ruts on Abbondanza is a function of time, not volume as the amount of wear on the curbstones and stepping-stones suggests a recent repaving. Repaving also solves the problem, which Wallace-Hadrill failed to mention, of unrutted streets inside the vice region. Still, the organized control of this area by one-way streets, in conjunction with the major blockages created by the demands of the water system, does in fact appear to isolate the region from the rest of the city. This portion of Regio VII was likely an area of dubious behavior and Via dell’Abbondanza was undoubtedly an important processional route. However, a careful study of the movement and restriction of traffic – fundamentally tied to the needs of the water system – demonstrates that this level of control did not purposefully serve to create and maintain a moral geography. 

This degree of control does, however, cast a brighter light on the complexity of Pompeii’s civic organization. Without doubt, maintaining a town of over 10,000 inhabitants was no mean task. Sadly, most evidence of that maintenance died with the inhabitants. However, through the citywide study of infrastructural systems, such as the management of water and traffic, especially in combination, both the breadth and depth of the civic organization can be rediscovered. What’s more, this new complexity forces us to challenge both old and new ideas about Pompeii. Could the aediles really have enacted and maintained such systems on their own? Put another way, could the systems survive the regular turnover of these oft-inexperienced officals? Was their number sufficient to administer both water and traffic? The consistency of the evidence shows great forethought in the decision making process for the armature of Pompeii. Additionally, the consistency implies a coherent system of rules, if not enforcement, ordering the flow of traffic. Was there a set of regulations akin to the Lex Juila on the Tabula Heraclensis or a handbook like that of Frontinus? Furthermore, when coupled with the complexity of this system, the consistency of the evidence implies an institutional memory that outlived the term of any official. In short, it implies what early imperial Roman government was supposed not to have: a bureaucracy. But, that is another paper… Thank you.