There is burgeoning interest in predicting road development because of the wide ranging important socioeconomic and environmental issues that roads present, including the close links between road development, deforestation and biodiversity loss. This is especially the case in developing nations, which are high in natural resources, where road development is rapid and often not centrally managed. Characterization of large scale spatio-temporal patterns in road network development has been greatly overlooked to date. This paper examines the spatio-temporal dynamics of road density across the Brazilian Amazon and assesses the relative contributions of local versus neighbourhood effects for temporal changes in road density at regional scales. To achieve this, a combination of statistical analyses and model-data fusion techniques inspired by studies of spatio-temporal dynamics of populations in ecology and epidemiology were used. The emergent development may be approximated by local growth that is logistic through time and directional dispersal. The current rates and dominant direction of development may be inferred, by assuming that roads develop at a rate of 55 km per year. Large areas of the Amazon will be subject to extensive anthropogenic change should the observed patterns of road development continue.

The simplistic portrayal of road development as a classic environment versus development debate may be because the indirect pathways connecting road building with environmental change are poorly understood. Recent road development in previously remote regions of Nicaragua provides an opportunity to investigate these pathways. This paper examines the effects of increased market access on household resource use on the Atlantic coast of Nicaragua. Specifically, it looks at shifting market flow and price changes for natural resources and corresponding fishing and farming decisions in communities with varying degrees of market access before and after road completion. Fisheries markets were more responsive to market access increases than agricultural markets. With increased access, fishers increasingly sold to non-local buyers, overall export of fisheries' products increased and markets for new products emerged. Prices of fisheries goods were higher with proximity to markets and availability of non-local export outlets, and prices for some were more stable after the road was completed. There were no observed changes in household fishing and farming investments during the year-long study, and therefore the environmental implications of increased market access remain uncertain. Longer-term studies and additional biological monitoring are needed to determine the full environmental consequences of market access.