Percentage Of Roads Research Articles

Hybrid Nonlinear and Machine Learning Methods for Analyzing Factors Influencing the Performance of Large-Scale Transport Infrastructure

Strategic maintenance is essential for sustainable road infrastructure development. Accurate estimation of road maintenance effects can support the assessment of maintenance strategies and reasonable allocation of budgets and resources. Road deterioration is affected by sophisticated factors, but accurate investigation of the integrated deterioration factors is limited. This study developed a dynamic trade-off model (DTOM), a hybrid nonlinear and machine learning method, for quantifying temporally varied impacts of factors and examining maintenance effects at the network level. Pavement deterioration factors are classified into three categories: (i) historical observations of roughness, (ii) pavement age, and (iii) traffic, climate and environment factors. Their respective impacts on pavements are estimated using a non-linear least square regression, a joinpoint regression and a random forest model, respectively. Vehicle-based laser scanner monitored high-resolution deterioration data was collected for a large spatial scale road network in Western Australia from 2007 to 2018. Results show that the resurfacing and rehabilitation are essential for strategic reduction of deterioration. Twelve-year maintenance activities reduced the distress of roughness by 7.5% and increased road performance (the percentage of roads with roughness lower than 2.085 IRI) by 14.5% for the whole road network. The DTOM has great potentials in accurately assessing infrastructure maintenance effects and predicting deterioration scenarios.

Soil and vegetation cover evaluation in the forestry area «Mekhzavodskoy» of the suburban Samara forestry enterprise area

The paper presents data on the state of soil and vegetation cover of oak forests of suburban forests near the village Mekhzavod. Being in the ring of large highways as well as located relatively close to Samara, they experience a complex impact of many adverse conditions. In the course of the study in these forest communities using the method of laying ecological profiles, we assessed a degree of recreational load impact on the vegetation cover of the green zone. The author estimated the percentage of road and path network development, described stages of recreational digression (for R.A. Karpisonova) and identified the main indicators of anthropogenic load, a vital status of major forest tree species and the factors contributing to its deterioration. The author also revealed a classification of soils with the help of laying soil profiles in different quarters and the subsequent chemical analysis of the selected samples. It is determined that the gray forest soils indicated for this area on the soil map of the Volga Region are not found. Taking into account the unsatisfactory state of the vegetation cover of the studied area, a number of recommendations for its rational use are proposed, which can further contribute to the preservation and improvement of these forests stability.

Effects of landscape on soundscape perception: Soundwalks in city parks

The present study analyses the effects of the physical characteristics of the visual landscape on soundscape perception in city parks, based on information gathered in field surveys using a specifically designed soundwalk method in five city parks in China. Three soundscape parameters were conceived, including perceived loudness of individual sounds (PLS), perceived occurrences of individual sounds (POS) and soundscape diversity index (SDI), which were found to correlate and should thus be applied in concert. Physical characteristics of the visual landscape were analysed from two perspectives, i.e., by on-site landscape composition and local landscape spatial patterns. The results suggest that the percentage of buildings, vegetation and sky in panoramic views (here photos) were effective landscape elements influencing soundscape perception. The landscape shape index of buildings and water areas (LSI_B, LSI_W) and the patch cohesion index of water areas (COHESION_W) showed positive effects on the perception of human sounds. The percentage of roads (PLAND_R) and the largest patch index of roads (LPI_R) were related to traffic sounds. Both the PLS and POS of biological sounds were negatively related to LPI_W and LSI_B, respectively, whilst the POS of biological sounds was positively related to PLAND_R, and LSI_R. COHESION_R was the only index negatively related to both the PLS and POS of geophysical sounds. SDI only showed positive relationship with PLAND_W. Overall, the results reveal that local landscape spatial patterns could be more influential on soundscape perception than on-site landscape composition. The study proposed introducing soundscape information from different sources into landscape management.

Local and landscape effects on the butterfly community in fragmented Midwest USA prairie habitats

The fragmented landscape of the Midwest USA includes prairie remnants embedded in an agricultural matrix, potentially impermeable to dispersing individuals. We examined butterfly responses to local (environmental variables measured within the prairie fragment itself such as vegetative characteristics) and landscape (environmental variables measured up to 2 km surrounding the fragment, but not the fragment itself) factors at 20 prairie remnants in Iowa. Our objectives were to: 1) document how the composition and configuration of the landscape affects butterfly community within the fragment, 2) determine whether explanatory power is gained by including both landscape and local variables rather than only local variables, and 3) analyze differences in butterfly community composition between linear and block shaped fragments. Results from partial least squares regression suggest there are significant effects of the landscape on butterfly community composition at all spatial extents investigated. The local variable that was most highly correlated with butterfly community response was percentage litter, while percentage of roads was the most important variable at all landscape spatial extents. Ordination diagrams clearly separate linear from block sites based on butterfly community composition. Variance partitioning using partial canonical correspondence analysis indicated that landscape variables at all spatial extents add additional explanatory power beyond local variables with little overlap in percentage of variation explained. Our results suggest that butterflies are making decisions based both on the local and landscape environmental factors, thus land surrounding prairie remnants should be included in management decisions.

A Database of World Stocks of Infrastructure, 1950-95

This article describes an annual database of physical infrastructure stocks for a cross-section of 152 countries for 1950–95. The database includes estimates of six measures of infrastructure: the number of telephones, the number of telephone main lines, kilowatts of electricity-generating capacity, kilometers of total roads, kilometers of paved roads, and kilometers of railway lines. Both raw and manipulated data sets, in which series have been linked to overcome changes in definition and coverage, are reported. Some measures of infrastructure quality, such as the percentage of roads in poor condition, the percentage of local telephone calls that do not go through, the percentage of diesel locomotives available for use, and the percentage of electricity lost from the distribution system, are included. The data on all series except total roads are of reasonably good quality and should prove useful to researchers. The article also presents regression results relating stocks of infrastructure to population, per capita gross domestic product, land area, and level of urbanization. It shows that stocks of telephones, electricity-generating capacity, and paved roads tend to increase proportionately with population and more than proportionately with per capita gross domestic product. Both the length of total roads and the length of total rail lines rise with country size and are relatively insensitive to population and income.