The research on commons dilemmas is characterized by innumerable published findings, each standing relatively isolated from the other. To date there is little integration of the findings under a unified concept. The present contribution aims to integrate already existing findings in a general dynamic model of cooperative behavior in resource crises by means of computer simulation. The model postulates that people base their decisions regarding resource use on both ecological and social information. Whether or not ecological or social information will dominate, however, depends on people's social values, attributions, and their perceptions of the state of the resource. The advantage of the simulation method used is that successful integration of the findings can be shown explicitly, as the simulation then replicates the experimental data. With the model presented here, it is also possible to let variables work together whose interaction has not yet been investigated in real experiments. For instance, the simulation model allows us to hypothesize that people, in dependency upon their resource uncertainty and in dependency upon their attributions, utilize a resource completely differently if the resource is in an optimal or sub-optimal condition.

Past research has shown that people with prosocial orientations exercise restraint when collectively shared resources are close to being depleted, whereas people with proself orientations tend to maintain high levels of consumption. This research seeks to extend this important finding by examining whether the presence of noise in social-ecological interaction may modify the effects of social values in a commons dilemma. Participants were taking resources from a gradually declining pool. For half of the participants, the intended consumption was subject to incidental increases in consumption (negative noise). Consistent with hypotheses, noise exerted detrimental effects on cooperation when resources became scarce, yet these effects were only observed for prosocials, not for proselfs. These results indicate that noise in social-ecological interaction plays an important role in common-pool management. It tends to undermine cooperation among those who are otherwise inclined to save resources .

Worldwide, more than one million people die on the roads each year. A third of these fatal accidents are attributed to speeding, with properties of the individual driver and the environment regarded as key contributing factors. We examine real-world speeding behavior and its interaction with illuminance, an environmental property defined as the luminous flux incident on a surface. Drawing on an analysis of 1.2 million vehicle movements, we show that reduced illuminance levels are associated with increased speeding. This relationship persists when we control for factors known to influence speeding (e.g., fluctuations in traffic volume) and consider proxies of illuminance (e.g., sight distance). Our findings add to a long-standing debate about how the quality of visual conditions affects drivers’ speed perception and driving speed. Policy makers can intervene by educating drivers about the inverse illuminance‒speeding relationship and by testing how improved vehicle headlights and smart road lighting can attenuate speeding.

Earlier research has repeatedly shown that people tend to follow group norms when using common pool resources. The present commons dilemma study seeks to extend these findings with two inherently relevant concepts: First, the ecological efficiency of the group norm, and second, the physical distance between the actors involved. Physical distance was manipulated by administering a web-based commons dilemma task to participants in the laboratory versus participants in the Internet. Ecological efficiency was manipulated by giving participants feedback about an overusing or a conserving group norm while the pool was either big or small. Conformity effects were strongest when the perceived group norm was ecologically efficient and participants were physically closer. Moreover, the effect of physical distance was mediated by the importance a person attached to the group's behavior. When physically farther apart, individuals attached less importance to the group's behavior and, as a consequence, showed less conformity. The results are discussed in the light of previous commons dilemma research and social psychological theories, and consequences for natural resource management are reflected. Some common pool resources and the environmental problems associated with them are rooted on a local level (e.g., residential waste disposal or fresh water use), but others have a rather global dimension (e.g., air pollution or the greenhouse effect). Although local problems may often affect us more than global ones, both types of environmental problems are an integral part of our everyday life and local action is often relevant for global resources as

The objective of this work is to understand if on urban roads, traffic safety can be linked to traffic congestion. To do so, crash data for the network of Zurich, Switzerland, is linked traffic data describing congestion from the same network. By aggregating the data, the crash risk in relation to traffic states is analyzed: (i) over the entire network for different times of day; and (ii) for individual links with different congestion levels.It is found that at the network level, the crash risk (number of crashes per car) is higher during times when the average network speed is lower (5-7 pm). Lower speeds are observed during this time period typically due to congestion. Hence, at the network level, there is evidence for congestion being an indicator of increased crash risk. During the same (congested) time period, it is also observed that crashes mostly happen on links with medium speeds, which could be due to higher speed variations within individual links during the congested time periods.