Spatial spillover effects between neighbouring ports can provide evidence of the degree of competition or complementarity within a port range and inform strategic or policy decisions on port investment. However, these effects have received limited attention in dry bulk ports, which account for around 25% of global port traffic by volume. We apply four spatial models - the Spatial Autoregressive Model, Spatial Error Model, Spatial Autocorrelation Combined Model, and Spatial Durbin Model - to 206 European bulk ports from 2005 to 2022 to examine the degree of spatial spillover effects across different dry bulk commodities. Our findings reveal negative spatial spillover effects associated with vessel size and number, which remain statistically significant after accounting for endogeneity in the aggregate model. However, these effects vary across commodity segments. For coal, the baseline SDM indicates negative indirect effects associated with vessel size and a positive total effect of vessel calls. In contrast, the IV estimates reveal significant negative indirect effects for both vessel size and number, while neither variable has a significant total effect. For ore, the negative indirect effects are consistent with a degree of substitution between neighbouring ports, whereas for agricultural ports, the findings are consistent with a more complementary spatial relationship. Our findings are consistent with different dynamics of competition across segments in European bulk ports, particularly when traffic is declining, as for coal, or relatively stable, as for ore.
Urban air mobility (UAM), enabled by electric vertical take-off and landing (eVTOL) aircraft, has been proposed as a possible response to urban congestion, but its effects depend on urban spatial structure and ground access. This paper develops a monocentric city model integrating endogenous residential and commuting-mode choices, road congestion, vertiport land allocation, and CBD production. Because eVTOL can replace long-distance ground travel while first-mile ground trips by eVTOL users generate additional traffic, we first consider a baseline case without this congestion feedback and then allow these first-mile ground trips to affect road loads and generalized commuting costs. Within this stylized planner benchmark, we compare the conditional welfare effects of eVTOL subsidies, public-transit subsidies, and first-mile infrastructure support.The analytical and numerical results show that eVTOL can support suburban residence for CBD workers, especially when CBD land is scarce, but does not necessarily relieve road congestion. Additional first-mile traffic may partly offset the reduction in long-distance ground travel. The numerical policy comparison indicates that eVTOL subsidies generate larger welfare gains under the benchmark setting, although their relative advantage diminishes as first-mile congestion increases. This change raises the relative value of public-transit subsidies and first-mile infrastructure support. These findings suggest that UAM services, vertiport capacity, and ground-access policies should be planned jointly rather than as separate components.
The U.S. transportation sector is undergoing rapid technological transformation, yet little is known about whether workforce recruitment and training practices align with emerging skill requirements. This study examines this mismatch through a survey of 105 transportation professionals from public agencies, consulting firms, and research institutions across the United States, of which 100 responses were retained after screening. Responses were analyzed with descriptive statistics and organized through a capability-demand framework comparing recognized skill needs with internal capacity, hiring priorities, and institutional constraints. Results reveal a substantial capability-demand gap: although nearly 90% of respondents recognized the need for expertise in emerging technologies, only 24.6% rated their internal capacity as high. Digital skills (programming, software, and automation) form the most frequently cited cluster of deficiencies (49.3% of respondents, rising to 58.6% among those reporting any gap), yet those areas rank last among hiring priorities: 8.2% of organizations prioritize programming and 13.7% prioritize technology and automation skills when recruiting, versus 72.6% for technical engineering skills. Structural barriers compound these challenges: among respondents reporting hiring difficulties, non-competitive salaries were the most cited obstacle (78.3%), and 64.9% reported unclear role definitions for emerging positions. Awareness of transformation needs is widespread, while the reported barriers concentrate in institutional structures such as job classifications, pay scales, and role definitions; these institutional constraints, rather than lack of awareness, appear to be the binding constraint on transformation among the responding organizations. Based on these findings, the study offers four practical recommendations: modernizing job classifications to accommodate hybrid roles, clarifying role expectations through technical competency frameworks, realigning salary structures to market conditions, and developing structured internal training pathways.
Aging is associated with changes in the structure of road safety risks, but the relationship between road network composition and elderly road safety remains poorly understood. We empirically examine the association between the ratio of mobility-oriented to accessibility-oriented roads and the elderly road death (ERD) rate. Using an unbalanced panel of 82 countries covering 1990–2023, we examine this association, including its direct component and its growth-mediated component through economic development. We find a U-shaped association between the mobility-to-accessibility (MTA) ratio and the ERD rate. Both relatively low and relatively high MTA values are associated with higher ERD rates, with the fitted relationship reaching its minimum at an intermediate MTA level. The association between road network composition and economic development varies across structural settings. While mobility-oriented infrastructure is positively associated with economic growth in highly urbanized and export-dependent economies, the association is weaker or negative in less urbanized and less export-oriented settings. These findings indicate that road network composition provides information beyond the aggregate size of road infrastructure when examining elderly road safety. The findings further suggest that the safety implications of road network composition vary with economic development, urbanization, and export orientation, highlighting the limitations of a uniform policy approach.
Air travel generates disproportionate greenhouse gas emissions, without viable supply-side mitigation options. Demand-side measures, such as emissions information at the point-of-sale, are thus gaining interest. In a pre-registered experiment with a nationally representative sample (N = 1000), we tested whether current emissions labelling systems shift consumers towards lower-emission flights. Participants were randomised to see either (i) no emissions information, (ii) absolute emissions values, (iii) absolute values with a relative emissions label or (iv) absolute values with a relative label and a contextual marker on the lowest-emitting flight (the number of trees needed to absorb equivalent CO2e reduction). In the first task, participants selected hypothetical holidays from an online booking site. The study's focus on environmental impact was concealed. Absolute emissions values had no effect, but the relative and ‘trees’ labels modestly increased low-emission flight selection (4-6pp). In the second task, participants were instructed and incentivised to select the lowest-emission flight. Absolute emissions improved identification by over 40pp, with no further benefit of additional labels. The relative labels caused some participants to choose higher-emitting flights (e.g., long-haul flights with large relative reductions). A final task measured comprehension of labels and showed widespread confusion: two-in-three misinterpreted the reference point for relative labels and few correctly identified the factors that are considered in label calculations. Overall, the findings imply that emissions labels, as currently implemented, are unlikely to reduce aviation emissions meaningfully and risk amplifying rather than correcting misperceptions.
