arXiv subjects

Andrew Renninger

Publications and source records attributed to Andrew Renninger.

12 recordsLinked to original sources

arXiv2026

The scales of urban mobility shape socioeconomic mixing

Urban daily mobility determines how far we travel and whom we encounter through the city. As local-living and polycentric planning gain popularity, a key question is whether more localised mobility can preserve the socioeconomic mixing that cities enable. Yet systematic evidence on how different scales of movement contribute to experienced social exposure remains limited. Here, we use anonymised GPS traces from ~20 million devices across 226 functional urban areas in France, Germany and the UK to decompose everyday mobility into three scales - proximal, medial and distal - and link these to the socioeconomic composition of destinations. Proximal trips remain similar in length across neighbourhoods, whereas medial and distal trips lengthen toward the periphery. Distal trips account for 33% of travel but facilitate 42% of inter-group encounters; reallocating them to local movement reduces experienced mixing by up to one third. These findings reveal a trade-off between shorter travel and integrated urban living.

physics.soc-ph↗

arXiv2026

Conflict, mobility and fragmentation in the African interurban network

Roads make regional integration possible, but they also concentrate risk. When violence reaches a corridor that carries regional movement, the consequences can extend beyond the attacked place. We study this problem in Africa by combining interurban road data, georeferenced conflict events, and bilateral migration flows. Using a Hawkes-style self-exciting memory kernel, we estimate accumulated conflict intensity near roads from 2019 to 2022, and we route modelled movement between cities along the road network. As an empirical check on these modelled corridor flows, we show that country pairs connected by routes with higher accumulated conflict have lower bilateral migration. The association remains negative across alternative assumptions about spatial decay and is strongest for paths that cross regions, consistent with a corridor-deterrence channel rather than only displacement from violent places. We then use cascade and percolation simulations to examine how local disruptions propagate through the road network. Most simulated disruptions isolate relatively small populations, but 18.6% isolate more than one million people, and the largest isolates 13.3 million. Removing roads in order of conflict intensity reveals a tipping point, at which the giant connected component falls from 85% to 39% of the network. Our results identify the roads where violence most threatens regional integration and show how past conflict, mobility, and network structure combine to create persistent corridor vulnerability.

physics.soc-ph↗

arXiv2026

No one likes it hot, but hotter cities adjust by staying active later

Extreme heat suppresses urban activity, but its effects need not be uniform across climates or across the day. Using data on activity at points of interest in 20 cities spanning temperate, tropical, and arid environments, we show that hot days reduce activity overall while shifting it away from midday and toward later hours. This rescheduling is substantially stronger in historically hotter cities, which exhibit smaller losses and larger evening substitution. To understand these changes, we introduce a Bactrian index of bimodality, which measures the degree to which a city's daily activity profile has one hump or two - one during the day and another during the evening. Arid desert cities like Doha, Amman, and Kuwait City are more Bactrian in level, but cities like Milan become Bactrian on hot days. Together, our results suggest that adaptation to heat in cities operates less through avoiding activity altogether than through moving it to cooler hours. This provides channels for adaptation in cooler cities, but it also suggests limits to adaptation in warmer ones: as evenings become warmer, these too may become intolerable.

physics.soc-ph↗

arXiv2026

The benefits and biases of seeing the world's cities through marathons

Marathons are now common ways of seeing cities, yet little is known about how representative their routes are. Using 311 marathon routes across five continents, we compare landmarks and amenities along the course with those elsewhere in the same city, finding that museums are 15.7 times denser near the route and that the median city has about 8.5 times more luxury brands near the route than elsewhere in the city. These patterns persist under perturbed routes with the same start and finish lines: monuments and landmarks, in particular, are more prevalent on the race course than on similar alternative routes, suggesting that marathons function as intentionally selective urban portraits.

physics.soc-ph↗

arXiv2026

Planning for isolation? The role of urban form and function in shaping mobility in Brasilia

Bras\'ilia offers a rare test of how urban form shapes experienced segregation. Built almost at once around modernist neighbourhood units, then expanded through planned satellites and informal peripheries, it lets us ask whether urban form turns mobility into mixing or into a more efficient engine of separation. We combine data on human mobility with urban morphometrics, amenities, road networks, along with enclosures and tessellations that capture segregation at the scales where access is structured: districts, neighbourhoods, blocks, and street-and-building cells. We find that segregation intensifies as resolution sharpens, from 0.282 at the district scale to 0.545 at the block scale, indicating that Bras\'ilia looks most integrated at coarse units and most segregated where everyday encounters are actually organised. Mobility softens home segregation for most users, but not symmetrically: poorer groups travel farther, while affluent groups remain the most selectively exposed. civic cores and mid-rise, mixed-use areas are the least segregated morphotypes, yet they occupy only a sliver of the metropolis. Elsewhere, rich lakefront suburbs and dense poor settlements reach similarly high segregation through opposite spatial logics. Amenities predict lower segregation, while barriers and enclosed residential interiors predict higher segregation. Built form explains more of this pattern than visit volume alone in the segregation models: integration is less a property of residential design than of shared destinations and porous connections. Planned capitals can build order without building isolation if they distribute mixing space rather than sequestering it.

physics.soc-ph↗

arXiv2025

Preliminary analysis of Sus scrofa movement using Hidden Markov Models and Networks

This study examines the complex movement patterns and behavioral characteristics of wild boars using GPS telemetry data collected over a two-month period. Our methodological approach centers on the application of a Hidden Markov Model (HMM) to discern distinct behavioral states embedded within the trajectories. Furthermore, the study aimed to construct behavioral networks, derived from these segmented trajectories. The resultant network structures showed that the hidden behavioral patterns are mostly independent of geographical locations. While most locations have many behaviors occuring in them, our findings also suggest that Finally, the research incorporates a spatial trajectory analysis, complemented by raster data validation, to potentially delineate areas acting as repellents within the ecological context of Hainich National Park in Germany.

physics.soc-ph↗

arXiv2025

Extreme heat reduces and reshapes urban mobility

Extreme heat is a problem in European countries and cities, with rising temperatures affecting ageing populations. Research on mobility during extreme heat remains limited to small samples and isolated contexts, leaving significant gaps in our understanding how entire populations adjust their day-to-day activities and how these adaptations vary across social groups. Here we use data from passive and active mobile network connections covering 13 million individuals in Spain (27% of the population) to examine extreme heat's impact on mobility at scale. We stratify by age, gender, economic class, and activity. Our findings show mobility falls by as much as 10% on hot days generally and 20% on hot afternoons specifically, when temperatures peak. Further differences emerge on hot days. Older adults cut travel to work and other activities, while those earning less are less able to avoid work; social mixing declines and spatial structure changes as activity falls in city centres. These disruptions have implications for urban economies, as curbed activity and interaction - both planned and unplanned - threaten the dynamism of cities as hubs of social and economic exchange.

physics.soc-ph↗

arXiv2024

Remote sensing and GPS mobility reveal heat's impact on human activity across diverse climates

Extreme heat is a growing threat to both individual livelihoods and broader economies, killing a growing number of people each year as temperatures rise in many parts of the world and limiting productivity. Many studies document the link between heat waves and mortality or morbidity, and others explore the economic consequences of them, but few are able to determine how populations respond to the shock of extreme heat in day-to-day activity. Toward this end, we investigate the link between human mobility and ambient temperature. Examining Indonesia, India and Mexico, we show that extreme heat reduces mobility by up to 10% in urban settings, with losses concentrated midday. We examine the shape of the relationship, finding that while heat reduces activity, very hot days and very long heat waves may induce more of it, indicating different adaptation. Effects are stronger in poorer areas. Twinning these models with climate projections, we show that without adaptation mobility may fall 1-2% per year on aggregate, with certain seasons and places seeing activity fall by as much as 10%. According to our estimates, small cities will face the highest relative losses and large cities will experience the greatest absolute impacts.

physics.soc-ph↗

arXiv2024

The role of central places in exposure segregation

Here we show that "exposure segregation" - the degree to which individuals of one group are exposed to individuals of another in day-to-day mobility - is dependent on the structure of cities, and the importance of downtowns in particular. Recent work uses aggregated data to claim that the location of amenities can inhibit or facilitate interactions between groups: if a city is residentially segregated, as many American cities are, then amenities between segregated communities should encourage them to mix. We show that the relationship between "bridging" amenities and socio-economic mixing breaks down when we examine the amenities themselves, rather than the urban aggregates. For example, restaurants with locations that suggest low expected mixing do not, much of the time, have low mixing: there is only a weak correlation between bridging and mixing at the level of the restaurant, despite a strong correlation at the level of the supermarket. This is because downtowns - and the bundle of amenities that define them - tend not to be situated in bridge areas but play an important role in drawing diverse groups together.

physics.soc-ph↗

arXiv2024

American cities are defined by isolated rings and pockets characterized by limited socio-economic mixing

Cities generate gains from interaction, but citizens often experience segregation as they move around the urban environment. Using GPS location data, we identify four distinct patterns of experienced segregation across US cities. Most common are affluent or poor neighborhoods where visitors lack diversity and residents have limited exposure to diversity elsewhere. Less frequent are majority-minority areas where residents must travel for diverse encounters, and wealthy urban zones with diverse visitors but where locals sort into homogeneous amenities. By clustering areas with similar mobility signatures, we uncover rings around cities and internal pockets where intergroup interaction is limited. Using a decision tree, we show that demography and location interact to create these zones. Our findings, persistent across time and prevalent across US cities, highlight the importance of considering both who is mixing and where in urban environments. Understanding the mesoscopic patterns that define experienced segregation in America illuminates neighborhood advantage and disadvantage, enabling interventions to foster economic opportunity and urban dynamism.

physics.soc-ph↗

arXiv2024

Disentangling individual-level from location-based income uncovers socioeconomic preferential mobility and impacts segregation estimates

Segregation encodes information about society, such as social cohesion, mixing, and inequality. However, most past and current studies tackled socioeconomic (SE) segregation by analyzing static aggregated mobility networks, often without considering further individual features beyond income and, most importantly, without distinguishing individual-level from location-based income. Accessing individual-level income may help mapping macroscopic behavior into more granular mobility patterns, hence impacting segregation estimates. Here we combine a mobile phone dataset of daily mobility flows across Spanish districts stratified and adjusted by age, gender and income with census data of districts median income. We build mobility-based SE assortativity matrices for multiple demographics and observe mobility patterns of three income groups with respect to location-based SE classes. We find that SE assortativity differs when isolating the mobility of specific income groups: we observe that groups prefer to visit areas with higher average income than their own, which we call preferential mobility. Our analysis suggests substantial differences between weekdays and weekends SE assortativity by age class, with weekends characterized by higher SE assortativity. Our modeling approach shows that the radiation model, which typically performs best at reproducing inter-municipal population mobility, best fits middle income and middle-aged flows, while performing worse on young and low income groups. Our double-sided approach, focusing on assortativity patterns and mobility modeling, suggests that state of the art mobility models fail at capturing preferential mobility behavior. Overall, our work indicates that mobility models considering the interplay of SE preferential behavior, age and gender gaps may sensibly improve the state of the art models performance.

physics.soc-ph↗

arXiv2023

Detecting the sensitive spots of the African interurban transport network

Transport systems are vulnerable to disruption. This is particularly true in Africa, where there are large areas with few highways and heightened risk of violence. Here we attempt to estimate the costs of violent events on African transport in order to understand the way that it may be limiting integration between regions. In the absence of detailed data on trade or migration, we quantify the cost of violence by relating observed incidents to imputed spatial interaction between cities. We produce indices representing the expected intensity of violent events $\mu$ and the expected strength of interaction $\nu$ between cities in the African interurban network. We estimate the intensity of conflict in a city and, considering the network of all highways on the continent, use a gravity model to generate flows between pairs of cities. We systematically compare $\mu$ to $\nu$ and classify areas according to their combined impact and intensity. Results show that certain cities and roads in the network contain outsize risk to Africa's transportation infrastructure. These cities have a high propensity for subsequent violence against civilians, and given their role in the network, they also substantially affect regional connectivity and thus economic integration. According to our model, removing just ten edges due to conflict would require rerouting 32$\%$ of trips. The top 100 edges where violence is likely to happen account for 17$\%$ of all trips. We find that cities with the highest $\mu-\nu$ risk are typically small and medium size with large degree, meaning they act as hubs. Vulnerable areas tend to be characterised by the presence of terrorist groups like Boko Haram in Nigeria or Al Shabaab in Somalia.

physics.soc-ph↗