In a world that is increasingly reliant on interconnected transportation systems to provide lifelines for cities and regions, how can we find truth? Our transportation systems are not just about moving people and goods from one place to another; they are complex sociotechnical ensembles that shape, and are shaped by, the societies they serve. And in Transport Truths: Planning Methods and Ethics for Global Futures, Greg Griffin explores the methods that underpin how we plan for transport, highlighting the need for a comprehensive approach to address modern challenges.

As an important entry in the Transport Futures series at Bristol University Press, the book emerges from a realization that traditional approaches to transport planning often fall short in addressing the wicked challenges of our time. The need for sustainable, equitable, and efficient transport systems has never been more pressing, yet the path to achieving these goals is fraught with complexities and contradictions. By integrating insights from diverse disciplines and employing a critical realist perspective, Griffin provides a comprehensive framework for understanding and addressing these multifaceted challenges.

For example, quantitative methods such as statistical analysis and traffic modeling provide valuable data on transport patterns and trends. However, they often fail to capture the nuances of individual experiences and the broader social context. deeper insights into these aspects but may lack the rigor and generalizability of quantitative approaches.

This chapter provides antidotes and warnings of the limitations of quantitative methods through qualitative innovation. I sequence case examples to determine how qualitative insights might be used in a transport study or plan. The first case involved developing an interviewing protocol spanning an ocean—students from Texas working with a team from Republic of The Gambia to support planning for increases in tourism in the West African country. Using the same partnership, I describe how a public participation geographic information system (PPGIS) can be used in online and paper-based formats to scale local knowledge. Next, I show how qualitative coding can be used to organize themes and concepts for research and practical applications, arguing that these methods are under-utilized by practitioners for turning public comments into practical guidance. As a capstone for qualitative research methods, I summarize a small-scale case study of a two-decade planning process for a pedestrian bridge in a socially contentious setting in Texas. This chapter positions futures storytelling as a critical method for transport planners, using cogent and impactful examples from the Greater Philadelphia Futures Group. If contextual match is an advantage of qualitative methods, assessing findings is more of a challenge, which this chapter supports through reflective guidance on the limitations of reliability and generalizability and the time and resource requirements of qualitative study. Finally, the chapter shows how to assess qualitative analysis from the ethical framework, showing how the approach supports the multiple levels of analysis from a critical realism ontology.

Quite a distance from technological capitals, the Republic of The Gambia provides a complementary perspective that nonetheless is in its own moment of turmoil between the rules of power and development. This context shows how adding airport capacity is valuable for enabling growth and cultural connection in a region of West Africa with limited ground transport. The capital city of Banjul is a critical historical case, as a site of colonization and enslavement, and now a growing industry of diaspora tourism. As a nation colonized by the British empire, surrounded by the former French colony of Senegal, The Gambia is a modernizing nation seeking financial growth and autonomy. This chapter leverages Achille Mbembe's development of decolonial theory for both conceptual inspiration and critical lenses to review findings and meaning for the nation's prospects (Mbembe, 2021).

In The Gambia, the eagerness to accelerate the development of transport infrastructure often leads to a complex dance with foreign direct investment (FDI). External credit comprises 57.6 percent of the country's debt stock, or 48.9 percent of gross domestic product (GPD) (International Monetary Fund African Dept, 2021). Real GDP is forecasted to grow in the 5– 6 percent range over the next few years, but another shock like the COVID pandemic could seriously endanger debt payments. This chapter delves into the particular investment of the Saudi Fund for Development's loan that enabled expansion of Banjul Airport—seizing a key opportunity to expand tourism, while deepening debts to foreign investors.

This chapter describes three paradigmatic changes in quantitative methods for transport planning: big data, causality outside of laboratory contexts, and machine learning approaches. In contrast with other scholars, I argue that big data is not all data—digital transport traces track technological objects rather than people and their transport decisions. I show this through a case of understanding micromobility, where e-scooter trips may be fully tracked under a corporate subscription model. However, many owned vehicles, including bicycles, provide no digital trace whatsoever. Therefore, reliance on data from shared mobility services may mis-represent the broader population of users. Planners relying on these forms of potentially biased ‘smart city’ information could inadvertently prioritize users of specific mobility services, creating a negative feedback loop. As an example, a planner identifying unsafe intersections by calculating the number of crashes per bike share trip—rather than performing bicycle traffic counts throughout a city—could prioritize areas in the central city and along recreational corridors frequented by tourists over the city's everyday bicyclists. Tracking rental trips is not the same as all trips for any travel mode. Understanding the prospects and limitations of quantitative analysis in transport is critical whether working on an individual project or an entire forest of transport issues.

This understanding argues in favor of new methods of data fusion—combinations of representative surveys and other methods with big data to mitigate bias while maximizing spatial and temporal accuracy.

Powerful research is about how we turn knowledge into action, both during and after a study. This chapter reviews the findings across the case studies, suggesting a growing emphasis on a critical realism approach to knowledge production may emphasize qualitative and mixed methods in transport to address systems of power for social and environmental progress. However, it provides counterpoints that knowledge of wicked problems may never be fully uncovered, and that mixed methods may over-complicate and needlessly delay finding suitable answers in some contexts. This chapter provides practical tools to assess how transport research is used in policy making, centered on how it is communicated. The concluding section points to the progress and problems that remain for researchers and scholars seeking transport truths.

A slow, steady rise for critical realism?

Traditional transport research has predominantly gravitated towards either positivist frameworks, which emphasize empirical observation and quantifiable variables, or interpretive frameworks, which prioritize subjective experience and contextual understanding. In this duality, critical realist approaches have been comparatively underutilized. Critical realism, a philosophy that combines elements of positivism and interpretivism, posits that while an objective reality exists, our understanding of it is always mediated by social, cultural, and linguistic factors. In other words, it seeks to understand not just the ‘what’ but also the ‘why’—the underlying mechanisms and structures that give rise to observable phenomena.

Every description of a transport context in the past or present is incomplete. There are always human experiences that remain unknown, just as with nonhuman impacts, such as to biota or structures. Conceiving futures about transport systems are even more fraught. Forecasting models rely on past data that was qualitatively chosen and manipulated, just as narratives we can tell about the future are fueled by personal experiences. Each perspective—each truth—is biased.

We must engage with the reality that any description of transport phenomena requires qualitative choices that guide which versions of data and stories the researcher or practitioner deems most important. To do so requires a critical review of how the way we think about these issues informs how we grasp reality, choosing between transport truths to guide decision-making. The thought process changes as an individual experiences, recalls, and selectively forgets knowledge about transport contexts. This experiential knowledge only scales up to organizational change to the extent that the experiences are communicated, recorded, and encoded as organizational changes.

This chapter shows four evolutions in how transport planners think: economic rationality, mobility vs. access, the role of public input, and dashboarding information for transport planning. Additionally, this chapter shows how each of these topics intersect with the LASTR framework—legitimacy, accessibility, social learning, transparency, and representativeness all play a role in transport planning's effectiveness, and can be analyzed in cases through a critical realist perspective.

On a warm June evening in San Antonio, Texas, Tina Galvan decided to take an e-scooter from one of the new shared schemes for a spin in the Government Hill residential district near downtown San Antonio. By the summer of 2019, e-scooter companies Bird, Lime, and Razor had rolled out systems rentable via smartphone apps, some of which required a brief safety guide before acceptance of their terms and conditions for use. Ms Galvan hit a small pothole and hit the asphalt hard.

‘When I came to my knee was swollen so bad I couldn't walk and (it was) bleeding, my forehead was bleeding, my teeth had gone through my bottom lip and my arm was broken,’ Ms Galvan told a radio reporter via telephone (Flahive, 2019). Galvan sued both Lime and the City of San Antonio for damages, claiming the scooter's design was not capable of safely navigating the pothole, which she could not see because of inadequate lighting and a lack of painted markings. Technologies—the new e-scooter, and the city's street conditions—were inadequate for the task, Galvan claimed.

E-scooter riders, the involved lawyers, and transport planners know that humans and technologies are intertwined factors in any transport problem. Industrial engineers designed the scooters with funding driven by venture capital, in a race to deliver the first, best product. City workers deliver services under political and economic conditions of their local council district, city, and sometimes regional, state, or federal funding. Everyday people traverse the city using complex ensembles of machines, navigation tools, and conversations with others about how to move around.

How do transportation planning organizations’ narratives guide discourse and results? This chapter shows how agencies merge quantitative forecasting and policy stories while building advocacy constituencies, revealing more of the underlying real transport social structure proposed from a UK context (Melia, 2020). Informed by critical realism, this study clarifies the mechanisms that lead to neo-advocacy planning, a concept developed by Gavin Parker and Emma Street as a response to the challenges of planning in neo-liberal contexts. In this chapter, I use the term neo-advocacy planning as an inverse of public opposition to agencies, where government agencies strategically leverage community groups through organizational communication that supports public opinion for their leaders’ dominant lobbying and voting constituencies.

‘No tolls on existing roads’ read one of many hand-written protest signs at the public meeting of the Capital Area Metropolitan Planning Organization (CAMPO)—the intergovernmental transportation group for the fast-growing Austin, Texas region. Crowds had gathered in a cool and dark auditorium in Anderson High School—moved from the normal small meeting room on the University of Texas campus—for the board's October 2007 vote on whether to include five toll roads in the region's transportation plan. Some shouted threats of ‘political suicide’ to the elected representatives on the board, led by then-state senator Kirk Watson (Wear, 2007). As a regional transportation planner for the organization at the time, I primarily analyzed land use and transportation data, and staffing events like this were also part of the job.