Scholars are taking a greater interest in the study of streets, which appear to be more important to the understanding of the ancient world than previously thought. Streets were in fact very lively, diverse spaces, subject to change over time, in which many different mechanisms operated and daily social contact took place. Eric Poehler is an authority on the urban structure and traffic systems of Pompeii and beyond. His work on these subjects (and extensive on-site analysis) has led to numerous publications in the past two decades on urban planning, street architecture and Roman traffic. These publications have formed a strong foundation for The Traffic Systems of Pompeii. By critically analysing large and complex datasets, Poehler is able to reconstruct the traffic systems of Pompeii and to situate them within the wider history of Roman urbanism and traffic. It should be pointed out that this book is not simply descriptive, but it also provides a methodological framework for other scholars interested in studying ancient streets, their traffic, and its management.

The book starts with an overview of modern scholarship on Roman roads and traffic. The evolution of Pompeii's urban street network from the archaic period to the post-earthquake periods is outlined in chapter 2. Here, Poehler argues for the existence of a master plan around 300 bc for all of Pompeii's urban form outside the Altstadt. Irregularities in block shape and orientation across the city, once interpreted by scholars as markers of chronological distinction, are explained instead as ‘compromises for both practical (topography, defence) and theoretical (aesthetics) purposes’ (p. 43). The argumentation is strengthened with excavation data (e.g. the existence of a quarry) to show that some chronological differences in the occupation of various parts of the city were reasonable and necessary.

The next three chapters offer an in-depth archaeological description and analysis of Pompeian streets. In chapter 3, the different street surfaces (i.e. beaten ashes or battuto, cobbles, lava stones or silex, and debris) are discussed. Chapter 4 examines the architectural elements of the streets: paving stones, curbstones, stepping stones and guard stones. The analysis and interpretation of the 370 so-called guard stones, found at the sides of the streets, is especially noteworthy. Poehler convincingly argues that guard stones served to protect elements of the water infrastructure, such as fountains, from the passing carts, but also the pedestrians on the sidewalks. The wear patterns of the vehicles on the architectural elements of the streets is the subject of chapter 5. Chapter 6 is the heart of the book and brings all the theoretical and technical analyses of the previous chapters together to investigate whether there were traffic systems for the circulation of vehicles in Pompeii. The regularity that lies at the basis of the distinctive wear patterns strongly suggests the presence of a shared behaviour of cart drivers. In order to explore these systems, Poehler clearly analyses the shape of the street network (intersections and corner shapes), one-way and two-way streets and their directionality, and chronological changes.

A different and surprising approach is taken in chapter 7, as Poehler takes the reader on a journey into the life of a Pompeian cart driver, named Sabinus. The fictional narrative, accompanied with many references, leads to several discussions about the management of traffic systems. After a thorough analysis of Pompeii, chapter 8 sets the road system into the broader history of Roman urbanism and traffic control. For this, Poehler has included the evidence for traffic in no less than 24 Mediterranean sites in Italy, Algeria, France, Greece and Turkey. The fact that the elemental building blocks of the traffic systems identified in Pompeii (one-way and two-way streets, right-side driving) are identifiable in the survey provides promising feedback for the methods used in the book. However, care should be taken with regard to the uniqueness of each site and its history. Poehler closes the chapter with a short history of Roman traffic management based on legal, literary, historical and epigraphic sources.

In the preface of the book, Poehler states that one of the aims of The Traffic Systems of Pompeii is to emphasize the value of archaeological data in solving this ‘archaeological puzzle’ (p. xv). This is borne out throughout the book; the thorough analysis and interpretation of 600 wear patterns, divided into overriding wear, sliding wear and cyclical wear, is especially impressive (chapter 5). The capacity of ruts for the study of vehicular traffic was first explored by Tsujimura (Reference Tsujimura1991), who made a distinction between one lane and two lanes of traffic based on rut pairs. Whereas the presence of ruts can give information on traffic circulation, Poehler shows that the wear on the vertical faces records the direction of travel. He carefully analyses the shape of the wear patterns by the position of the street feature and the angle of intersection with the wheel. Poehler also includes a necessary note on documenting the level of certainty for the interpretation. This is a good way to evaluate the interpretation and the method used and to structure the results. Moreover, although wear patterns can hardly be dated, Poehler found a way to study chronological changes to the directionality by looking at the relation of the wear patterns to (datable) innovations in the streetscape, such as the public fountains (chapter 6). His close focus on the archaeological record has allowed reconstruction of the direction of the traffic, to describe the proposed system now in greater detail.

Study of the streets and their wear patterns serves as a proxy to reconstruct traffic behaviour. However, it does not give insights into the types of movement or the journeys that were made. The lack of street signs and the information that they might have contained could be of importance to a full interpretation and description of traffic systems. In this regard, chapter 7 forms a valuable addition, as it successfully shifts the focus of the reader from the preceding theoretical part of the book to an examination of corresponding social and practical aspects. Through the journey of Sabinus from the Casa del Menandro to the Porta Saliniensis, the reader experiences the feel of the (busy) streets, the detours, pedestrians, encounters with other drivers and their attitudes, and the difference between inhabitants and foreigners in the navigation through the city.

Another discussion is concerned with control over the streets. Poehler first considers the misconception of this control in the introduction (pp. 17–19). There, he forcefully points out that all the aspects of the street and traffic were the products of on-going negotiations between individuals and municipal governments. Control is not invested in the individual alone, as is argued by other scholars. The consistency of the evidence for traffic, the many events of paving and repaving (legally announced and enforced by the magistrate) and the absence of private initiatives for (re)paving at individual properties are only some examples that clearly show the control of the municipal government. Poehler mentions that some Pompeians chose certain surfaces and street architecture (e.g. tessellated pavements on the sidewalks in front of their house) to portray their status and identity (pp. 73–6). This phenomenon is also known from other studies (Hartnett Reference Hartnett, Laurence and Newsome2011; Saliou Reference Saliou1999, 199). Poehler rightfully states that the fact that house owners were responsible for the sidewalks in front of their building does not mean that they were in charge of the streets, or that they could do anything they pleased without consequence. Public judgement and critique played as much of an important role as the will to stand out. Furthermore, there are legal sources that recorded the rights and responsibilities of both parties (pp. 202–4 & 234–5; Hartnett Reference Hartnett, Laurence and Newsome2011, 143–7).

How, then, were the rules from the magistrates enforced on the people using the streets? This is also an important aspect of the system that can easily be overlooked. As Poehler poses, it is very likely that the magistrates themselves had one or more drivers and that the magistrates’ social hierarchical networks played an important role in the transfer of information as well as in motivation to follow the rules. Sabinus’ journey through the city has shown that observation of the environment and other drivers were other crucial ways to gain information. The potential existence of street signs or maps is also kept in mind and briefly discussed.

To conclude, Poehler shows how to use diverse and abundant archaeological datasets, combined with (art-)historical, literary and epigraphic sources, to tackle some issues of Roman urbanism and traffic to a sophisticated level. Of course, there still remain questions that will hopefully be solved in future studies. The Traffic Systems of Pompeii is rich in data and a valuable addition to previous research on street networks in the Roman world. The presentation of the data with 13 tables and 76 figures is very clear and supportive of the arguments. This book will be of interest for anyone dealing with the ancient past and with those searching for ways to make sense of it.