Search

This paper describes the procedure used to design a stable concrete replacement for a gravel durability test road. The replacement road was designed analytically to match the cumulative fatigue damage of the gravel road and consisted of individual test events that existed on various vehicle proving grounds. Although this paper deals specifically with road replacement, the method could easily be adapted to road comparison, i.e., proving ground to proving ground or customer to proving ground.

This paper describes a real-time road following and road junction detection vision system for autonomous vehicles. Vision-guided road following requires extracting road boundaries from images in real-time to guide the navigation of autonomous vehicles on the roadway. We use a histogram-based pixel classification algorithm to classify road and non-road regions in the image. The most likely road region is selected and a polygonal representation of the detected road region boundary is used as the input to a geometric reasoning module that performs model-based reasoning to accurately identify consistent road segments and road junctions. In this module, local geometric supports for each road edge segment are collected and recorded and a global consistency checking is performed' to obtain a consistent interpretation of the raw data. Limited cases of incorrect image segmentation due to shadows or unusual road conditions can be detected and corrected based on the road model. Similarly, road junctions can be detected using the same principle. The real-time road following vision system has been implemented on a high-speed image processor connected to a host computer. We have tested our road following vision system and vehicle control system on a gravel road.

On 1 December 1989, an intensive cultural resources survey was conducted by the Environmental Analysis Branch of the U.S. Army Corps of Engineers, Memphis District, over approximately one acre of land of a permit area. The area was cleared but covered with grass and a gravel road. The area is located in Township 12N, Range 2E, NW, SE1/4 of Section 6 on the Risher quadrangle map, Poinsett County, Arkansas. A literature search indicated that site 3PO224 is in the project area. A pedestrian survey of the project area failed to locate any cultural indicator or remains.

From introduction: The Annie Laurie 'cranium Prospect, in the Oro Blanco district of southern Arizona, is located in the southwest quarter of Sect. 3, T233, R=13. The nearest United States post office is Nogales, about 25 miles east, and the nearest settlement is Ruby, a nearly abandoned mining camp about 3 miles north. Access to the Ruby area is by gravel road from US highway 39 at Kinsley or Nogales. The Ruby quadrangle (1940) includes the area surrounding the prospect.

"If animals avoid road surfaces or are unable to follow conspecific trails across such surfaces, previously continuous populations may be fragmented. We gathered data on the effects of a small (4-m wide) gravel road on the behavior and trail-following abilities of garter snakes (Thamnophis sirtalis parietalis) in Manitoba, central Canada. As expected, the road surface had less vegetation cover, a more open canopy and, thus, higher incident radiation than did the surrounding grassland. Contrary to expectations, however, substrate temperatures were lower on the road than in its surrounds, because of the higher reflectivity of the road's surface. On a nearby asphalt road, substrate temperatures were relatively high on the road surface only in the evening, as surrounding areas cooled. Focal sampling showed that snakes avoided the gravel road, typically changing direction when they encountered it. If they crossed the road, they did so by the shortest possible route (straight across). Mate-searching male snakes were less able to follow substrate-deposited pheromonal trails left by females if those trails crossed a road than if the trails were entirely within the surrounding grassland. Thus, roads may significantly modify snake movement patterns, as well as the ability of males to locate reproductive females. Our study provides the first detailed information on the effects of roads on snake behavior."

The 93 km section of Highway 3 located between Behchoko (Rae-Edzo) and Yellowknife is located in an area with warm and discontinuous permafrost and variable ground ice contents. The highway was originally constructed as a gravel road in 1968. Between 1999 and 2006, the alignment for this section of highway was straightened and reconstructed, and the road surface chip-sealed. To date, this section of highway has experienced significant sagging in soil-covered areas and requires considerable maintenance efforts to keep the road in a comfortable and safe driving condition. Embankment deformations have been attributed to the degradation of the ice-rich permafrost foundation. The Public Infrastructure Engineering Vulnerability Committee (PIEVC), a national committee established by Engineers Canada, has developed a standardized protocol to assess the vulnerability of Canada's public infrastructure to climate change. The protocol continues to be tested on a variety of public infrastructures and in 2010, this section of highway was evaluated as a case study. More than 1100 highway infrastructure element - climate event combinations were assessed. Out of these combinations, five were identified as "high risk". The assessment identified those sections of the highway built on ice-rich permafrost as being at greatest risk, based on its low capacity to withstand the projected or anticipated climate-change related loads. Overall, the road embankment stability was found to be insensitive to climate change such that only functionality losses are expected, not sudden losses in capacity. Climate change will likely increase maintenance and repair efforts needed to maintain safe driving conditions.

In automobile design, the safety of passengers is of prime concern to the manufacturers. Suspension is one of the safety-related automotive systems which is responsible for maintaining traction between the road and tires, and offers a comfortable ride experience to the passengers by absorbing disturbances. One of the critical components of the suspension system is the knuckle, which constantly faces cyclic loads subjecting it to fatigue failure. This paper presents an evaluation of the fatigue characteristics of a knuckle using a gravel road profile acquired using a data acquisition system and standard SAE profiles for the suspension (SAESUS), bracket (SAEBRAKT) and transmission (SAETRN). The gravel road profile was applied as the input to a multi body simulation (MBS), and the load history for various mounting points of the knuckle is extracted. Fatigue life is predicted using the strain-life method. The instantaneous stress distributions and maximum principal stress are used for fatigue life predictions. From the results, the strut connection is found to be the critical region for fatigue failure. The fatigue life from loading extracted from gravel road MBS agreed well with the life prediction when standard SAE profiles were used. This close agreement shows the effectiveness of the load extraction technique from MBS. This method can also be effectively used for more complex loading conditions that occur during real driving environments.

In this study we examined the relative importances of soil factors, the presence of non-native grasses and the distance from seed sources of native species in explaining variation in natural revegetation among sixteen abandoned gravel pads in arctic Alaska

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.