- •Министерство образования республики беларусь
- •К сборнику прилагается тематический словарь основных понятий, необходимых при работе над переводом текстов.
- •History
- •Driving on the Right or on the Left
- •Construction
- •Maintenance
- •Unit 2 Sweet Track
- •Unit 3 Roman Road
- •Types of Roads
- •Milestones
- •Way Stations
- •Vehicles
- •The itinerary
- •Construction of a Road
- •Financing
- •Unit 4 Roman Roads in Britain
- •Unit 5 Silk Road
- •Origin: Cross-continental Travel
- •Ancient Transport
- •Egyptian Maritime Trade
- •Persian Royal Road
- •Hellenistic Conquests
- •The Roman Empire and Silk
- •Central Asian Commercial & Cultural Exchanges
- •Mongol Era
- •The Great Explorers: Europe Reaching for Asia
- •Unit 6 Royal Road
- •Course of the Royal Road
- •History of the Royal Road
- •Unit 7 Inca Road System
- •Main Routes
- •Inca Rope Bridges
- •Renewing the Last Bridge
- •Unit 8 Types of Road
- •Definition
- •Medium Capacity
- •High Capacity Restricted Access Roads
- •United Kingdom
- •United States Freeways
- •Expressways
- •Unit 9 Highway
- •Nomenclature
- •Social and Environmental Effects
- •Unit 10 Motorway
- •Regulations and Features
- •Common Criteria
- •Speed Limits
- •Lane Usage
- •Junctions
- •Location and Construction
- •Unit 11 Freeway
- •General Characteristics
- •Effects and Controversy
- •History
- •Recent Developments
- •Unit 12 Autobahn
- •Construction
- •History
- •Current Density
- •Speed limits
- •Traffic laws and enforcement
- •Unit 13 Causeway
- •Derivation of the word
- •Engineering
- •Examples of Use
- •Precautions in Use
- •Unit 14 Street
- •Role in the Built Environment
- •Circulation
- •Vehicular Traffic
- •Parking for Vehicles
- •Pedestrian Traffic and Vehicular Amenities
- •Identity
- •Nomenclature
- •Unit 15 Trail
- •Walking Trails
- •Bicycle Trails
- •Equestrian Trails
- •Trail Construction
- •Trails on Slopes
- •Drainage
- •Multi-use Trails
- •The Trackways
- •Settlements
- •Wallingford
- •Brownhills
- •Cadbury Castle and South Cadbury Village
- •Unit 17 Pavement (material)
- •Metalling
- •Asphalt paving
- •Concrete Paving
- •Bituminous Surface Treatment (bst)
- •Other Paving Methods
- •Unit 18 Traffic Sign
- •History
- •Vocabulary
Equestrian Trails
Horseback riding has continued to be a popular activity for many trail users. Again, horse trails must be built to different standards than other trails. Sight distance is an important issue with horse trails, as is overhead and side clearance. While trail surface types are a relatively insignificant issue with hikers, they may be an important issue with horses. Horses can negotiate much steeper terrain on a dirt trail, for instance, than on a gravel trail. Horses can usually negotiate much the same grades as hikers, but not always, although they can more easily clear obstacles in the path such as logs. A hard trail surface and drainage is a critically important issue on horse trails because of the relatively greater bearing impact of the horse’s hoof on the trail than a hiker’s foot.
Trail Construction
A walking path.
While many trails have arisen through common usage, quality trail design and construction is a complex process requiring certain sets of skills.
When a trail passes across a flat area that is not wet, often all that is required is to clear brush, tree limbs and undergrowth to produce a clear, walkable trail. When crossing streams, bridges may or may not be desirable, depending on the size of the stream and the depth of its banks. In wet areas, it may be necessary to create an elevated trailway with fill or by building a boardwalk. One problem with boardwalks is that they require frequent maintenance and replacement - boards in poor condition are often slippery and hazardous.
Trails on Slopes
This trail leads straight over the hill.
A common mistake in establishing trails is to make them on slopes that are too steep for comfort and the environment. Such steep trails generally result in serious erosion, a wide swath of impacted area as walkers go to the sides to find better footing, and the inability of many hikers to walk the trail. An absolute limit for trail grades is a grade of one in six, and a more practical limit is a slope of one in eight. Trails that ascend steep slopes may use switchbacks (also called hairpins), but switchback design and construction is a specialized topic that takes great care. The best trail designs eliminate switchbacks.
If a trail is being made to be accessible to off-road wheelchairs, the grade should be no more than one in ten. If a paved trail has to be accessible to all wheelchairs, the grade must be no more than one in twelve, with periodic level pull-offs.
The off-slope, or side-slope, of the trail also must be considered. This is the slope of the trail from side to side, and should never be more than one in twelve. Side-sloped trails are prone to gullying. Ideally, the treadway of the trail should be almost, but not quite, level in cross-section.
Achieving the proper slope in hilly terrain usually requires the excavation of sidehill trail. This is trailway that is constructed by establishing a line of suitable slope across a hillside, then digging out by means of a mattock or similar tool to create the trail. This may be a full-bench trail, where the treadway is only on the firm ground surface after the overlying soil is removed and thrown to the side as waste, or a half-bench trail, where soil is removed and packed to the side so that the treadway is half on firm old ground and half on new packed fill. In problem areas, it may be necessary to establish the trail entirely on fill. In cases where filling is used, it’s necessary to pack it firmly and to revisit the site periodically to add to the fill and repack it until fully stable.