Wednesday, December 21, 2011


Alan Kaiser, Roman Urban Street Networks. Routledge Studies in Archaeology, 2. New York; London: Routledge, 2011. Pp. xvii, 249. ISBN 9780415886574. $125.00.

Reviewed by Jeremy Hartnett, Wabash College (

Version at BMCR home site

Amidst a growing interest in Roman urban thoroughfares and especially movement along them,1 this book offers a quantitative methodology for describing and assessing the organization of space in Roman cities. Borrowing tools from urban geography, such as access analysis, Kaiser studies the street networks of four well-preserved cities from various times and places in the empire (Pompeii, Ostia, Silchester, Empúries). Veterans of these sites will find that this book opens their eyes to issues of accessibility and connectivity across the urban fabric, even as the study's conclusions largely confirm suppositions about the cities' organization. Perhaps the greatest value of this innovative methodology lies in the aggregate, however, since it permits the cities to be set in conversation with one another for comparative purposes. Such a juxtaposition reveals certain common features of Roman cities and also highlights the unique circumstances of individual examples.

Historiography and methodology dominate the introduction and first two chapters. The introduction traces the influence of the urban geographer Kevin Lynch on studies of Roman urbanism.2 Kaiser draws on textual and visual evidence to support Lynch's emphasis on "paths" (i.e., streets) as one of the key elements by which Romans perceived of and came to understand their cities, but he also stresses the need to find additional methods to "analyze streets and understand their role in the creation and use of urban space" (p. 12).

The bulk of Chapter 1, "Textual Evidence for Roman Perceptions of Streets and Plazas," is dedicated to the vocabulary used to describe streets. Kaiser argues that whereas English words for urban thoroughfares are based primarily on physical properties (e.g., alley, boulevard), Latin terms added a more charged cultural connotation to the material component. Romans demonstrate a tendency to divide streets into two camps: main thoroughfares (via, platea) and side streets (angiportum, semita). Generally speaking, when the former are employed in texts of various stripes, it is in connection with public acts, from parading a condemned criminal to dedicating an honorary arch. The latter terms were less frequently associated with social display and could be used in reference to realms such as commerce and industry. As Kaiser puts it, "Angiporta and semitae were the streets people used to conduct more private activities that they did not want to share with the community by conducting them on the wide, busy, public streets" (p. 45). This textual survey is valuable for the information it supplies about Roman attitudes about street types, but employing those sentiments as a yardstick for measuring or categorizing what is found on the ground seems less convincing.

Chapter 2, "Defining and Analyzing Street Networks in the Archaeological Record," seeks to establish an approach that "investigate[s] the role of each street in relation to every other street" (p. 47). After laying out some of the physical features of streets, plazas, and the like, Kaiser attempts to sharpen such generic labels as "main streets" and "side streets" by applying three quantitative measures. These derive from the pioneering work of Hillier and Hanson, whose form of analysis—which is most often called "space syntax" or "access analysis"—uses simple numeric data to draw conclusions about a street's role in its city network.3 Kaiser's first index of a street is its "depth" from outside the city, in other words, "how many streets and plazas one must pass through" in order to move from the city's edge to the street in question (p. 53). A street that leads directly from a gate, then, has a depth of one. The second index, depth from the forum, involves the same concept, but counts the number of streets away from this "practical center of the city" (p. 54). Third, the number of intersections a street shares with other streets is another useful analytical attribute, as it describes "how well a particular street integrates or segregates the streets of the city" (p. 56). Finally, Kaiser undertakes, to the degree the surviving evidence allows, an assessment of how much a given street was open to cart traffic. Kaiser's primary analytical tool for the depth and intersection data is a comparison between the number of different types of buildings (residential, commercial, etc.) along a given street and the number we would expect if there were an even distribution of those buildings throughout all streets of a city. Are shops concentrated disproportionately, for instance, on streets with a lower depth from city gates? At Pompeii, the answer, according to a standard chi-square test, is an emphatic "yes."

This methodology has the advantage of providing an objective, data-driven approach to examining how the cities in the case study fit together. (The "network" in the book's title is key.) It favors issues of accessibility and connection in the urban fabric over physical proximity, which is often the focus of such discussions. The result is a book driven by maps and tables, without any photographs of a street from a pedestrian's perspective. One downside, then, is that their treatment in the case studies can leave the cities feeling very much like moribund laboratories for statistical evaluation rather than spaces pulsing with life. A greater degree of clarity would have been welcomed with regard to the categories of "primary" and "secondary" streets into which all thoroughfares of the case studies are slotted. Chapter 1's text-based analysis drives the creation of such a polarity, but are individual streets assigned to a category because of their physical characteristics, their scores according the depth and intersection metrics, or some other basis? The statistical analysis might have been more valuable in exploring tensions between the ideal laid out in texts and the reality played out on the ground.

Each of the next four chapters tackles a single city under Rome's dominion to do the heavy lifting of Kaiser's analysis. The sites in question, all from the western half of the Mediterranean, have a majority of their intramural area exposed through excavation; a major benefit is the inclusion of cities beyond Roman Italy. Each of the chapters proceeds formulaically. As background, it outlines layout, topography, and history of the city in question; the author then discusses the structure of the city's streets; and next comes an assessment of how well we can identify building uses from the archaeological record. Kaiser then devotes a section of each chapter to analysis of the city's street network on the basis of the four criteria spelled out above (street depth from city gates, street depth from the forum, the number of intersections a street had, and its accessibility for cart traffic). Finally, each chapter identifies and discusses the primary and secondary streets along with the forum and any plazas. Extensive tables supplement plans of the cities, and color-coded maps showing different uses of space are available at an on-line supplement to the book.4

Chapter 3 is dedicated to the most famous of the case studies, Pompeii. The abundant evidence here allows Kaiser to move beyond his standard categories of architectural units and to introduce additional subcategories, such as bakeries, brothels, and non-elite housing. The analysis of the street network supplies few surprises: the streets leading to either the forum or the city gates (an overlapping group) are most densely packed with doorways and also host more commercial properties, fountains, and spaces dedicated to production than an even distribution would suggest. These were the busiest streets and hosted the greatest diversity of building types. Against this backdrop, the much-discussed restriction of wheeled traffic on several of these streets (such as portions of the Via dell'Abbondanza) comes into higher relief; it supports the argument that rumbling carts bore a strong stigma for Romans. Secondary streets at Pompeii were much quieter, with fewer destinations lining their streetface, yet played host to the residences of the nonelite disproportionately. Whether the owners of smaller houses sought out back streets or could only afford these locations is not clear.

The boomtown at Rome's port, Ostia, provides a more complex situation in Chapter 4. Here much of the street network, as we have it, emanates from a central east-west spine that ultimately led to Rome. As at Pompeii, commercial structures and bars tended to cluster on streets with low depths from city gates and the forum, while residences, by contrast, appeared with greater than expected frequency along streets that had higher depths. This tendency to live on more remote streets, Kaiser suggests, could have resulted from a desire to be isolated from the greater number of non-residents who passed through this commercially-oriented city. On a related note, Ostia also had a greater degree of "directionality," that is, its streets' clear hierarchy made it easy for strangers to find their way to the forum or out of the city.

Chapter 5 moves far in distance, time, and density to the British site of Silchester, whose remains document a rural town set amidst a productive countryside in the third and fourth centuries. After Claudius' invasion of Britain, a new street grid was superimposed over what had been a Belgic settlement. Over time, stone structures gradually replaced those in wood, yet within its walls the site retained much open space, which could have hosted grazing or housed markets. On the one hand, Silchester offers the best illustration of Kaiser's methods, since he successfully complicates what on the surface seems like a simple gridded town layout. He demonstrates how the forum, though central geographically, was not very well integrated into Silchester's street network, but nevertheless hosted a great concentration of commercial properties. This suggests that entrepreneurs catered primarily to the city's residents, rather than visitors. On the other hand, this chapter also raises questions about the book's approach, since initial excavations here recorded only stone structures (and not wooden ones), which forces Kaiser to take account of a limited subset of Silchester's buildings. What was missing here, or along the streets within Ostia's walls that have not been subject to open-air excavation? And what impact might gaps have had on the statistical analysis?

In Chapter 6, the final case study, Empúries in Spain, engages these questions somewhat, since it intentionally studies only a subset of a larger conurbation. The original Greek settlement of Neapolis represented an organically- evolved neighborhood that eventually was paired with a Roman colony laid out on a grid plan (the so-called Ciudad Romana). Kaiser nicely shows how Neapolis' organization of space differed markedly from the other case studies, noting the role of its agora as an integral space through which traffic moved. The argument that such phenomena resulted from Neapolis' Greek heritage is strengthened when Kaiser sets the city in comparison with its immediate neighbor, Ciudad Romana, whose sparse remains nevertheless sketch out a pattern of use similar to the three previous case studies.

The conclusion argues that the example of Neapolis/Ciudad Romana illustrates the potential for applying the book's methodology to partially excavated urban sites. Yet there is reason to hesitate on this score, for when statistical anomalies arise in the Neapolis case study, the book has to examine specific circumstances to explain them away. Nevertheless, the Empúries comparison illustrates the book's strongest suit: the side-by-side analysis of Roman cities. This book's individual chapters will profit scholars specializing in each city, but the most profound points emerge when the book is read in its entirety. Kaiser's work exposes some dynamics and phenomena that might otherwise slip by and provides critical context for sites like Pompeii that can occasionally be taken as "typical" or paradigmatic for Roman urbanism. All in all, Kaiser should be commended for bringing a new and rigorous approach to these cities and for arming scholars of Roman urbanism with a toolkit for interrogating other street networks and the placement of buildings within them.


1.   E.g., Laurence, R. and Newsome, D. (eds.), 2011. Rome, Ostia, Pompeii: Movement and Space, Oxford.
2.   Lynch, K. 1960. Image of the City, MIT Press.
3.   Hillier, B. and Hanson, J. 1984. The Social Logic of Space, Cambridge.
4.   Roman Urban Street Networks online supplement

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