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Due to importance of developing the North and Arctic territories, it is essential to ensure working capacity of machinery in cryolithozone. To solve these problems, it is necessary to study accumulation of structural damage and changes in material properties. The purpose of this article is to study influence of operation in the northern roads conditions on fatigue damage, brittle fracture resistance and the working capacity of a leaf spring of a KAMAZ truck widely used in Yakutia. Methods of mathematical statistics, metallography, microindentation, standard mechanical tests, etc. were applied. Results of analysis of distribution of the KAMAZ vehicle springs failures on the months of the year are given, taking into account the seasonal changes in a profile of the typical for Yakutia gravel road. To assess the fatigue damage of metal, the structural and statistical study of microhardness (microdamage) and porosity (mesodamage) was carried out. Impact toughness values were determined and it was found that the accumulated damage did not lead to metal embrittlement at low temperatures. The more significant impact of the cryolithozone road microprofile on the working capacity of the KAMAZ truck springs as compared to the factor of the low temperatures has been substantiated.

Small-scale race events are a popular form of recreation in natural areas with the potential for social and environmental impacts. Leave No Trace-based communication and education strategies are the most prevalent form of mitigating recreation impacts on public lands. To understand competitive race participants’ perceptions of Leave No Trace, this exploratory study compared race event participants’ attitudes, evaluative beliefs, and global perceptions of Leave No Trace by event type: gravel road running, trail running, mountain biking, and motorcycle trail racing. Data were collected using online post-event surveys. Participants were sampled from five competitive race events on public land held during fall 2015 to summer 2016. Significant differences between event types were found for all constructs examined. Motorcycle racers were the least likely to agree that Leave No Trace is an effective method for protecting the environment, least likely to believe that humans have the potential to cause social or environmental impacts, and were the least willing to change their behavior if they found out it was damaging the environment. Runners’ attitudes toward specific Leave No Trace behaviors were the least in line with Leave No Trace recommendations, while mountain bikers were the most in-line. Management implications When issuing permits and managing events on public natural areas, managers should approach each affair differently, realizing that the type of event may influence the level of social and ecological impact. Managers should contact event organizers as early as possible to raise awareness of possible impacts, provide tailor-made messaging to participants, and develop management plans specific to the event and location that monitor and adaptively manage impacts to preserve social experiences and ecological resources. This will help managers remain flexible in their event management.

In 2009, pulp mill fly ash was used for stabilizing the road base of a low-volume gravel road. Six years after stabilization, a two-year monitoring program and a complementary study were conducted ...

Sweden has a wide network of gravel roads. When the water table levels rise during the freeze-thaw and wet seasons, the bearing capacity of the roads will decrease and rut depths increase. The road will suffer a small deterioration every time a vehicle travel over it. Therefore, it has been decided to investigate the long-term performance of a Swedish designed gravel road using an accelerated pavement testing facility. A trial gravel road was constructed and exposed to various levels of ground water table which simulate the weather changes in Sweden. The structure of the trial gravel road consisted of 15 cm (base and surface layer), 20 cm sub-base layer and 260 cm subgrade soil. The trial road was tested using the Heavy Vehicle Simulator (HVS) and the vertical surface deformations and the vertical dynamic deformations were measured by means of laser profile measurement and eMU coils respectively. At the end of 85 000 HVS passes, the tested road suffered from serious deformations as discussed in details in this paper. Furthermore, a transverse trench section was excavated at the end of HVS trafficking in order to investigate the possible mechanism contributing to the tested road failure.

This study presents the performance of a trial gravel road subjected to HVS (Heavy Vehicle Simulator) trafficking in a compressed time period. The road structure was constructed with 150 mm-thick aggregate base course, and 125 mm-thick sub-base course. The test road responses, such as surface deformation and rutting were recorded using laser profile measurement instrument while the unbound layers’ dynamic deflections and strains data were periodically recorded at different depths during the execution of the test by means of an array of micro strain gauges. The test road was also instrumented with Water Content Reflectometers to record the changes in moisture contents in the road layers caused by the raising of the water table level under HVS trafficking. A total number of 85,000 HVS passes were applied to the trial gravel road structure under near-optimum as well as partially submerged subgrade moisture conditions. The test results emphasize the fact that the partial soaking of the subgrade soil by raising the groundwater table level caused a serious damage to the tested gravel road, as further detailed in this paper.

The rural population of India lack adequate transport infrastructure to access the nearby towns/headquarters. The Ministry of Rural Development (MoRD), Government of India (GoI) decided to develop various rural roads under Pradhan Mantri Gram Sadak Yojna (PMGSY). The main objective of PMGSY is to achieve all weather connectivity to all habitations. Hence, a pilot study was initiated over a 7 km gravel road stretch from “Ghanapur-Palakurthy Public Works Department (PWD) Road to Komatigudem via Ippagudem, and Rangaraigudem” in the Warangal district of Telangana State, India. There are various disadvantages associated with construction using gravel like dust generation and gravel loss over a period of time due to passage of vehicles. The best solution to minimize these problems is to seal the gravel roads. The pilot road considered in this study was constructed using locally available gravel up to the surface course and then sealed using surface dressing. The performance of the road sections were evaluated in terms of roughness, skid resistance, and texture depth. The initial set of data was collected immediately after construction and one month after construction. Later, four sets of pavement performance data was collected after seven months of construction of the surface dressing layer in November 2013, January 2014, April 2014, and June 2014. Altogether, six sets of data were collected. The data was analyzed and important observations are reported in this paper. There is a considerable change in surface texture and skid resistance values after the first one month of construction whereas no significant changes were observed in the roughness values. Further, there is no significant difference in the results of surface texture, skid resistance and roughness values when the pavement sub-sections were evaluated for four times even after seven months of construction of the sealing layer.

Traffic-generated fugitive dust on gravel roads impairs visibility and deposits on the adjacent environment. Particulate matter smaller than 10 μm in diameter (PM10) is also associated with human health problems. Dust emission strength depends on the composition of granular material, road moisture, relative humidity, local climate (precipitation, wind velocity, etc.), and vehicle characteristics. The objectives of this study were to develop a reliable and rapid mobile methodology to measure dust concentrations on gravel roads, evaluate the precision and repeatability of the methodology and correspondence with the currently used visual assessment technique. Downwind horizontal diffusion was studied to evaluate the risk of exceeding the maximum allowed particulate matter concentration in ambient air near gravel roads according to European Council Directive [European Council Directive 1999/30/EC of 22 April 1999 relating to limit values for sulphur dioxide, nitrogen dioxide and oxides of nitrogen, particulate matter and lead in ambient air. Official Journal of the European Communities. L163/41.]. A TSI DustTrak Aerosol Monitor was mounted on an estate car travelling along test sections treated with various dust suppressants. Measured PM10 concentrations were compared to visual assessments performed at the same time. Airborne particles were collected in filters mounted behind the vehicle to compare the whole dust fraction with the PM10 concentration. For measuring the horizontal diffusion, DustTraks were placed at various distances downwind of a dusty road section. The mobile methodology was vehicle and speed dependent but not driver dependent with pre-specified driving behaviours. A high linear correlation between PM10 of different vehicles makes relative measurements of dust concentrations possible. The methodology gives continuous data series, mobility, and easy handling and provides fast, reliable and inexpensive measurements for estimating road conditions to make road maintenance more efficient. Good correlations between measured PM10-values, visually assessed dust generation and dust collected in filters were obtained. PM10 seems to be correlated to the whole dust fraction that impairs visibility on gravel roads. A decay in PM10 concentration as a function of distance from the road was observed. Measured particles principally did not travel further than 45 m from the road. The risk of exceeding the PM10 concentration stated in the EC-directive seems small.

The measurement of soil erosion rates under natural rainfall conditions is costly and time consuming. Data provided by rainfall simulation and static site measurements can be used to predict erosion rates under natural conditions, however the accuracy of this method is largely untested. This is especially true for erosion rates from unsealed forest roads. In this study, the values for a range of erodibility indices calculated from rainfall simulation experiments are compared to observed erodibility index values from 1 year of detailed in-situ erosion monitoring of seven different forest road types. The prediction of phosphorus generation rates from rainfall simulation and/or soil sampling was also evaluated. The results showed that a series of commonly used erodibility indices such as sediment per unit rainfall, sediment per unit runoff, sediment per unit EI30, and sediment per unit rainfall energy were poorly predicted from the rainfall simulation experiments. Five of the six indices tested substantially overpredicted the observed erodibility at one site, a gravel road subjected to minimal traffic. For the other six road sites predictions were poor and highly variable, the coefficient of efficiency ranging from − 13.32 to 0.17 for these erodibility indices. A modified index, the ratio of sediment per unit rainfall energy to the mean rate of rainfall energy input, was able to predict annual erosion rates from six different road surfaces using rainfall simulation data with a coefficient of efficiency of 0.9. The results indicate that existing erodibility indices are not suitable for predicting observed erosion rates on forest roads using rainfall simulation data as collected in this study. It is argued that the modified index is more suited to sites (such as compacted roads) where interrill processes dominate, and erosion rates are less sensitive to peak flows. With respect to nutrient generation rates, rainfall simulation was able to accurately predict the observed proportion by mass of total phosphorus (TP) in runoff with a coefficient of efficiency of 0.96. Direct soil sampling of the road surface could also be used to predict the proportion by mass of TP in runoff. Concentrations of total nitrogen in forest road materials were found to be at the lower detection limit of the laboratory instruments.

Roads are a wide spread and increasing feature of most landscapes, have great ecological impacts, alter landscape spatial patterns and interrupt horizontal ecological flows strongly. Soil erosion is the dominating factor of damaging terrene roads in rural areas worldwide. Field tests for anti-erosion and maintenance techniques on terrene roads were conducted between 1996 and 2001 in Xiabiangou, Yan’an City in the Loess Hilly-Gully region of Shaanxi Province, China. The results of field tests showed that soil erosion on unpaved terrene roads with no vegetation was 3.09 times that of roads designed using special pavers sown with grass in the same situation. Roads sown with Bromus inermis , Elymus sibiricus , Elymus , Poa annua could bear traffic loads up to 300 vehicles year −1 . There were additional yields in benefits from fresh vegetable and seed production by B. inermis with strip sowing amounted to US$ 264.16 km −1 year −1 , while that for Coronilla varia and Lespedeza dahurica was between US$ 138.36 and US$ 205.52 km −1 year −1 , respectively. In order to avoid nutrient loss in the grass growth on the roads it is necessary to apply fertilizers to compensate for the decline in soil nutrients. The cost of grass road construction was 71.65% less than that of stone roads, with maintenance costs averaging 60.97% less than that of non-grass terrene roads. The results suggest that grass roads can fill the gap between paved and unpaved roads in areas with sloping terrain and low traffic volumes (rural countryside, nature reserves and parks) and thus minimize the level of soil erosion, landscape damage and other environment problems.

Runoff and sediment loss from forest roads were monitored for a two-year period in a Pinus plantation in southeast Queensland. Two classes of road were investigated: a gravelled road, which is used as a primary daily haulage route for the logging area, and an ungravelled road, which provides the main access route for individual logging compartments and is intensively used as a haulage route only during the harvest of these areas (approximately every 30 years). Both roads were subjected to routine traffic loads and maintenance during the study. Surface runoff in response to natural rainfall was measured and samples taken for the determination of sediment and nutrient (total nitrogen, total phosphorus, dissolved organic carbon and total iron) loads from each road. Results revealed that the mean runoff coefficient (runoff depth/rainfall depth) was consistently higher from the gravelled road plot with 0.57, as compared to the ungravelled road with 0.38. Total sediment loss over the two-year period was greatest from the gravelled road plot at 5.7 t km−1 compared to the ungravelled road plot with 3.9 t km−1. Suspended solids contributed 86% of the total sediment loss from the gravelled road, and 72% from the ungravelled road over the two years. Nitrogen loads from the two roads were both relatively constant throughout the study, and averaged 5.2 and 2.9 kg km−1 from the gravelled and ungravelled road, respectively. Mean annual phosphorus loads were 0.6 kg km−1 from the gravelled road and 0.2 kg km−1 from the ungravelled road. Organic carbon and total iron loads increased in the second year of the study, which was a much wetter year, and are thought to reflect the breakdown of organic matter in roadside drains and increased sediment generation, respectively. When road and drain maintenance (grading) was performed runoff and sediment loss were increased from both road types. Additionally, the breakdown of the gravel road base due to high traffic intensity during wet conditions resulted in the formation of deep (10 cm) ruts which increased erosion. The Water Erosion Prediction Project (WEPP):Road model was used to compare predicted to observed runoff and sediment loss from the two road classes investigated. For individual rainfall events, WEPP:Road predicted output showed strong agreement with observed values of runoff and sediment loss. WEPP:Road predictions for annual sediment loss from the entire forestry road network in the study area also showed reasonable agreement with the extrapolated observed values.

Testing Re-Entrained Kinetic Emissions from Roads (TRAKER) is a new technique to infer paved and unpaved road dust PM 10 emission potentials based on particulate matter (PM) measurements made onboard a moving vehicle. Light scattering instruments mounted in front and behind the vehicle's tires measure the differential particle concentration of dust suspended by the vehicle's tire in contact with the road surface. Through empirical regressions relating the differential concentration (i.e. TRAKER signal) with the vehicle speed and the downwind flux of PM 10 particles from the road, an equation is derived to infer the speed independent road dust emission potential from the measured TRAKER signal. Measurements from TRAKER offer a new perspective on the processes that affect road dust emissions. The system was used to investigate temporal changes in emission potentials from paved roads in both the winter and summer in the Treasure Valley in Southwest Idaho. During the 3-week wintertime sampling period, the residential road dust PM 10 emission potential decreased by ∼50%. Summertime PM 10 emission potentials were similar to those observed at the end of the winter sampling and showed no upward or downward trends. Wintertime unpaved road emissions increased consistently with the number of days since the last rainfall. Measurement of road dust emission potentials after road sanding on dry roads indicated a 75% increase in PM 10 emissions after 2.5 h. This effect was short lived and emission potentials returned to their pre-sanding levels within 8 h of the sand application. Street sweeping with mechanical and vacuum sweepers was found to offer no measurable reduction in PM 10 emission potentials. On several roads, the PM 10 emission potentials actually increased immediately after vacuum sweeping. Long term effects of street sweeping on road dust emissions were not evaluated as part of this study and may offer some overall reduction in PM emissions from paved roads.

The testing re-entrained aerosol kinetic emissions from roads (TRAKER) road dust measurement system was used to survey more than 400 km of paved roads in southwestern Idaho during 3-week sampling campaigns in winter and summer, 2001. Each data point, consisting of a 1-s measurement of particle light scattering sampled behind the front tire, was associated with a link (section of road) in the traffic demand model network for the Treasure Valley, ID. Each link was in turn associated with a number of characteristics including posted speed limit, vehicle kilometers traveled (vkt), road class (local/residential, collector, arterial, and interstate), county, and land use (urban vs. rural). Overall, the TRAKER-based emission factors based on location, setting, season, and speed spanned a narrow range from 3.6 to 8.0 g/vkt. Emission factors were higher in winter compared to summer, higher in urban areas compared to rural, and lower for roads with fast travel speeds compared to slower roads. The inherent covariance between traffic volume and traffic speed obscured the assessment of the effect of traffic volume on emission potentials. Distance-based emission factors expressed in grams per kilometer traveled (g/vkt) for roads with low travel speeds (∼11 m/s residential roads) compared to those with high travel speeds (∼25 m/s interstates) were higher (5.2 vs. 3.0 g/vkt in summer and 5.9 vs. 4.9 g/vkt in winter). However, emission potentials which characterize the amount of suspendable material on a road were substantially higher on roads with low travel speeds (0.71 vs. 0.13 g/vkt/(m/s) in summer and 0.78 vs. 0.21 g/vkt/(m/s) in winter). This suggested that while high speed roads are much cleaner (factor of 5.4 in summer), on a vehicle kilometer traveled basis, emissions from high and low speed roads are of the same order. Emission inventories based on the TRAKER method, silt loadings obtained during the field study, and US EPA's AP-42 default values of silt loading were compared. PM 10 paved road dust emission inventories calculated with the TRAKER method were 61% higher in winter and 180% higher in summer than inventories calculated from on-site silt loading measurements. Emissions calculated from silt loading measurements conducted on-site indicated that the AP-42 default values are too low for the Treasure Valley by a factor of 1.5 for summer conditions and by a factor of 3.8 for winter. Both silt loading and TRAKER are techniques that were calibrated against the horizontal flux of dust, which was estimated by the difference in PM 10 concentration between instruments located upwind and downwind of an unpaved road. The upwind/downwind method, and therefore both silt loading and TRAKER, gives a measure of the dust emitted near the source, and not the dust that can be transported on a regional or air shed scale. Correcting the measured dust emissions for deposition and removal near the source is outside the scope of this work, but is a continuing area of research among dispersion modelers.

Testing re-entrained aerosol kinetic emissions from roads (TRAKER) is a vehicle-based method for measuring road dust emissions. Particulate matter is sampled in front and behind a vehicle's tire and the difference in PM concentration is related to emissions. This paper describes the most recent developments of TRAKER. The loss of particles within the inlet lines, the response of the TRAKER signal (differential PM concentration) to vehicle speed, and the relationship between the TRAKER signal and unpaved road dust PM 10 emissions were examined. Losses of particles to the walls in the inlet lines were similar for the left and right inlets and were less than the inter-instrument precision for particles between 0.56 and 7.3 μm in diameter. When summed over the PM 10 size range, losses were less than 20%. Line losses were also characterized when a dilution system was used to sample emissions from unpaved roads. Two independent tests indicated that the TRAKER signal increases as the cube of the speed for a given road dust loading. Simultaneous measurement of PM 10 dust emitted behind the tires by TRAKER with PM 10 flux measured using upwind/downwind towers suggested that the emission factor for road dust was proportional to the cube root of the TRAKER signal. The results also showed a linear relationship between unpaved road dust PM 10 emissions and vehicle speed.

Thawing soils can severely restrict vehicle travel on unpaved surfaces. However, a variety of materials and construction techniques can be used to stabilize thawing soils to reduce immobilization problems. The US Engineer Research and Development Center's Army Cold Regions Research and Engineering Laboratory (CRREL) and the Wisconsin National Guard evaluated several stabilization techniques in a field demonstration project during spring thaw at Fort McCoy, Wisconsin, in 1995. Additional tests on chemical stabilizing techniques were conducted at CRREL's Frost Effects Research Facility. The results of these test programs were reduced to a decision matrix for stabilizing thawing ground, and used during the deployment of US troops in Bosnia during January and February of 1996. The soil frost and moisture conditions expected during this time frame were predicted using MIDFROCAL (MIDwest FROst CALculator). This paper is an overview of the stabilization techniques evaluated and their recommended application based on the expected soil frost conditions and traffic requirements. Although the experiments were performed with military vehicles in mind, the techniques are suitable for many civilian applications such as forestry, construction, mining, and oil exploration.

The importance of rural transport services in developing countries and the effects of vehicle–road interactions on total cost are outlined. Previous work on relationships between soil characteristics, tyres sizes, sinkage and rolling resistance is reviewed. An experiment using a range of typical transport vehicle tyre sizes to measure rut depth and area in a soil bin is described. The results are compared with corresponding relationships derived from some of the earlier work and it is concluded that a strong relationship exists between mobility number and tyre sinkage, which is largely independent of tyre size. An investigation into the potential for a reduction in rutting through the use of various geotextiles is also described. An application of the work to further research in the field is briefly outlined.

The heat stability of embankment in the degrading permafrost district of Chang Shitou Mountain in Hua Shixia Valley is modeled. Critical heights of embankment for asphalt, concrete and gravel road surface along the National Road of Qinghai-Sichuang are figured out by computers, according to the natural geographical and geological conditions of Hua Shixia Valley. The modeled results are in good agreement with the field data on the Qinghai-Xizang Highway. The heat-stable critical heights of embankment for asphalt, concrete and gravel roads are figured out as 4.30, 1.40 and 1.00 m, in the 20th year following construction from regression analysis. Besides according to the calculation results, when the height of embankment is more than 5.0 m for asphalt road, there is an upper thawed core above the artificial permafrost table in embankment after more than 10 years following construction, although the artificial permafrost table under the road is located above the natural permafrost table in the whole process of road running. So the frost deformation of embankment would be increased and could not reach the requirement of deformation designing. But for concrete and gravel road, there is no upper thawed core in embankment (the heights of embankment are less than 5.0 m. Finally, the authors think that it is important that the running time after construction is introduced into the determination of the critical heights of embankment in cold regions, particularly more important in degrading permafrost regions.

Two different methods employed in constructing gravel road—1st. Roads with paved (Telford) foundations. Gravel; its desirable qualities. Samples of gravel obtained from the surrounding country. Pit-gravel and sea-shore gravel. Binding material. Failure in the trial of sea-shore gravel. Recapitulation of the qualities of gravel. Treatment of gravel on the roads. Screened gravel used. How binding material was applied. Shaping and rolling road. Failure to pack gravel without binding material. Evidence developed from year to year of the qualities of gravel road. Superiority of screened gravel road; its striking economy. Analysis of screened gravel roads, and of broken stone road. Gravel road for common roads.