Alex Scott

States and port authorities have implemented “Clean Truck” programs (CTPs) to encourage trucking companies to transition to newer, cleaner trucks to reduce the emissions around ports. We examine the comparative effectiveness of mandatory and voluntary CTPs implemented across major United States ports. Leveraging insights from the awareness‐motivation‐capability framework, we theorize how environmental regulatory programs shape carrier behavior under different regulatory structures in the trucking industry. Using a difference‐in‐differences design and a database containing detailed truck and trailer information and air quality measures, we find that mandatory programs significantly accelerate truck model‐year upgrades, narrowing pre‐existing disparities in fleet upgrades across carriers, whereas voluntary programs show no measurable effects. Mandatory CTPs are associated with reductions in nitrogen dioxide concentrations, while effects on particulate matter are less consistent. Air quality improvements are most pronounced in inner harbors and decrease with distance from port activity. Our findings contribute to supply chain and regulatory policy literature by highlighting the effectiveness of mandatory environmental programs in driving industry‐wide change and the limited impact of voluntary initiatives.

Purpose: This paper examines the impact of precision scheduled railroading (PSR), an efficiency-driven reform, on the safety and operational performance of US Class I freight railroads. Leveraging Competing Institutional Logics and Stakeholder Theory perspectives, the study explores how PSR institutionalizes efficiency logic while constraining safety logic, generating performance gains at the expense of elevated operational risk. Design/methodology/approach: Using archival data from 2011 to 2024, the study employs a panel dataset of Class I railroads to assess changes in operational metrics (e.g. train length, locomotive utilization, workforce size) and safety outcomes (e.g. accidents, derailments) following PSR adoption. A difference-in-differences approach with carrier fixed effects and information-theoretic model comparisons is used to assess the robustness and heterogeneity of effects across rail carriers. Findings: Results indicate that PSR is associated with improvement in operational efficiency through longer trains, increased locomotive utilization and workforce reductions; yet these improvements are accompanied by higher derailment and accident rates. The pattern reflects an institutionalized safety–efficiency paradox, where efficiency logic dominates organizational priorities, advancing shareholder interests while compromising safety considerations for frontline stakeholders. Notably, in the rail industry, the safety–efficiency paradox impacts extend beyond frontline operational workers, also negatively affecting communities where rail carriers operate. Originality/value: Through integrating Competing Institutional Logics with Stakeholder Theory, the study reveals how PSR prioritizes efficiency logic while subordinating safety priorities, producing uneven outcomes across stakeholder groups. These insights refine the boundary conditions of the safety–efficiency paradox and offer theoretical and practical guidance for balancing operational performance and safety in infrastructure-intensive transportation systems.

Background: Carbon pricing in the form of fuel taxes is an important tool for abating climate change. This study examines the impact and pass-through of fuel taxes in the truckload freight market. Methods: State-level truckload market data, integrated with retail diesel prices, are analyzed using fixed-effects regression modeling. Results: Taxes and fuel costs are not only passed on by diesel retailers to motor carriers; the results reveal the overshifting of diesel taxes from motor carriers to shippers. Conclusions: The findings are consistent with inelastic short-term demand for long-haul carriage, indicating that relatively large price increases will be necessary to reduce diesel consumption in the trucking industry.

Many states have legalized medical and recreational marijuana use in the past decade, which has potential consequences for roadway safety. Using a state‐level panel of heavy truck crash statistics from 2005 to 2021 and a difference‐in‐difference estimation strategy, we test whether legalization has affected crash rates. Our results show that legalization does not increase crash rates on average; however, responses are heterogeneous across states, with Colorado, New Jersey, and Washington (state) showing crash reductions, while Connecticut and Virginia saw crashes increase. These results suggest that marijuana legalization does not have a straightforward relationship with heavy truck accidents, warranting continued research and policy scrutiny.

Theories developed for understanding the general management or economic phenomena are increasingly ineffective for explaining logistics/SCM‐specific phenomena, despite the best efforts of LSCM researchers to utilize them for those purposes. Unfortunately, the hierarchies and infrastructure in place to ensure LSCM research is theoretically grounded and conducted with scholarly rigor have not advanced to a point where the use of alternative methods to explore such questions is common. The key objective of this paper is to guide where empirical LSCM research could evolve if it took its relationship with theory a step further. Our thesis is that inductive research using empirical data can yield additional insightful answers to relevant questions. We hope that discussion of these topics from a 2024 perspective can spur more research that uses empirical analysis as a starting point to create new theory in LSCM and, importantly, to persuade members working in our field to respect and accept rigorous empirical research conducted outside the traditional deductive, logical positivist paradigm.

Although safety within operational systems depends on compliance with regulations, non-compliance is common in many settings. Trucking is a meaningful industry for studying operational safety compliance given that the industry is large and important, truck accidents kill thousands annually, and such accidents collectively cost the U.S. economy billions of dollars. Although the truck driving occupation is dominated by men, significant efforts are underway to recruit more women into the profession. If women are safer behind the wheel than men, increasing their ranks could improve overall safety compliance. Building on theory and evidence suggesting that men have a greater willingness to take risky actions and break rules, we used data on 22 million truck inspections from 2010 to 2022 to identify an operational safety compliance gap between men and women truckers. Overall, men were 7.4% more likely to be cited for a major violation of rules governing working hours (known as hours-of-service or HOS rules) and 13.2% more likely to have a major unsafe driving violation. We then examined whether gap changes based on carrier size and type. We found that the HOS compliance gap is smaller for small carriers (vs. large) and private carriers (vs. for-hire), but not the unsafe driving gap. Finally, we tested whether the introduction of an intervention—electronic logging devices (ELDs) that automatically record truckers’ driving hours—closes the gap by increasing men's compliance. In line with predictions, differences between men and women disappeared after the mandate; but again, only for HOS compliance. Surprisingly, women had significantly more HOS violations in 2021 and 2022 than men—an outcome that may be tied to women truckers’ personal safety issues. In summary, the results and additional robustness checks indicate that men committed more unsafe driving violations (e.g., speeding) than women across the entire study period, while the pattern of HOS violations varied based on external events. We conclude by highlighting possible pathways for reducing the number of collisions involving trucks and thus lowering the number of fatalities and extent of economic losses.

The logistics industry in the United States has faced significant labor shortages for the last couple of decades. Women are a source of labor that has been traditionally underrepresented in the major logistics sectors, transportation, and warehousing. We study the workforce composition and potential gender wage gap across these sectors. Using data from the U.S. Census Bureau from 2003 to 2020, we show that women comprise about 4% of the workforce for truck drivers and 21% for warehouse workers. As traditionally measured by economists, there is a 17% gender wage gap among truck drivers and an 11% wage gap among warehouse workers. A regression analysis suggests that the gap is smaller for warehouse workers, which is consistent with theory that an occupation's stability and predictability can reduce or eliminate wage gaps. Further analysis is carried out on specific occupations within the logistics industry and measures the variation across truck transportation and warehousing industries. There is evidence for a declining gender wage gap across both over time, although the gap remains sizable. This paper provides insight on the trends and status of gender differences in labor outcomes in the logistics industry.

Ensuring motor carriers comply with safety rules is critical to the efficient workings of supply chains and the safety of the motoring public. However, little is understood regarding how carriers respond to changes in the likelihood of inspection (a.k.a., “crackdowns”) undertaken by the Department of Transportation. Drawing on the regulatory compliance and criminology literature, we extend the rational cheater explanation that undergirds carrier safety research by incorporating principles from attention‐based theory to devise new theoretical predictions regarding how carriers respond to announced versus unannounced inspection crackdowns. To test our theory, we rely on exogenous variation in the probability of inspection from the DOT's use of announced and unannounced inspection “blitzes.” We test predictions using a longitudinal dataset of nearly 10 million truck inspections from 2012 to 2016. We find firms with lower costs of compliance, and higher costs of avoiding inspections improve compliance prior to and during announced blitzes. Small firms with lower costs of avoidance tend to avoid announced blitzes. Unannounced blitzes result in no changes in compliance or avoidance, providing evidence that awareness is driving our results.

There is mixed evidence on the effectiveness of voluntary environmental programs. We evaluate a voluntary program aimed at reducing transportation emissions, that is, the U.S. EPA SmartWay Program. We construct a novel database of the physical assets used by firms before and after they joined SmartWay and compare changes in the age of their assets with that of firms that did not join SmartWay. Our results show that firms that participated in SmartWay operate substantially newer (i.e., cleaner) trucks compared with non‐SmartWay participants, indicating that SmartWay participation is a credible signal of a firm's reduced emissions footprint emanating from truck operations. After the start of SmartWay, firms that joined invested in newer trucks relative to firms that did not, with about a year reduction in average truck age several years after the program began. SmartWay had a larger effect on firms that own their trucks compared with firms that outsource ownership, and sustained participation increased the program's effectiveness. We estimate that the SmartWay Program has reduced commercial transportation emissions from operations by 25.2 million metric tons of CO₂ by increasing the incentive to invest in newer, cleaner trucks. Our study provides insight into factors that make voluntary environmental programs effective.