Unit 1: history of road building

Предисловие

Данное учебное пособие предназначено для студентов 1 курса автодорожного факультета технических ВУЗов.

Целью учебного пособия является развитие и совершенствование умений и навыков устной речи в деловой и общепрофессиональной коммуникации, формирование профессионально ориентированной лингвистической компетентности студентов.

Деление на главы осуществляется в соответствии с тематикой. Учебное пособие состоит из четырех тематических глав. Первая глава посвящена строительству автомобильных дорог, вторая – организации и безопасности дорожного движения, третья – строительству автодорожных мостов и тоннелей, четвертая глава раскрывает особенности использования строительных и дорожных машин. Каждая тематическая глава включает в себя соответствующие разделы (Units), посвященные таким проблемам как: «История строительства дорог», «Основные элементы дороги», «Этапы строительства автодороги», «Типы дорожного покрытия», «Дорожные развязки», «Дорожные знаки», «Дорожная разметка», «Типы мостов», «Этапы строительства мостов», «Методы строительства тоннелей», «Строительная техника для расчистки территории, отведенной под строительство автодороги», «Строительная техника для формирования дорожного покрытия» и т.д.

Данное учебное пособие направлено на развитие разных видов речевой деятельности: чтения, диалогической и монологической речи, навыков письменного и устного перевода.

Каждый раздел (Unit) включает тексты для ознакомительного, изучающего и просмотрового чтения, которые содержат актуальную информацию из аутентичных источников. Тексты сопровождаются подробным словарем, а также значительным количеством иллюстраций, что привлекает внимание студентов и облегчает понимание представленного им материала.

Разделы также включают в себя лексические упражнения, направленные на расширение словарного запаса по специальности. Предусмотрены задания для индивидуальной, парной и групповой работы, в которых студенты создают и участвуют в коммуникативных ситуациях профессиональной направленности, что способствует уменьшению языкового барьера при реальном общении с носителями языка. Таким образом, каждый текст сопровождается упражнениями, имеющими коммуникативную направленность и позволяющими активизировать приобретенные навыки в речи.

Представленные задания помогут студентам научиться вести беседы на темы вышеуказанных сфер деятельности на английском языке, тем самым формируя общее представление об области дорожного строительства. Таким образом, изучив представленные в учебном пособии материалы, студенты смогут на базовом уровне участвовать в процессе коммуникации на профессиональные темы.

Каждый раздел содержит контрольные задания (Final Tasks), направленные на контроль усвоения пройденного материала.

Учебное пособие может быть использовано как для работы в аудитории, так и для самостоятельной работы.

 

CHAPTER I. HIGHWAY CONSTRUCTION

UNIT 1: HISTORY OF ROAD BUILDING

1. Before you start. · Who built it? · How do you think when was the first road built? · What was its purpose?

Read the words and learn them by heart.

1. to tend – стремиться, иметь тенденцию к чему-либо

2. to take for granted – принимать как само собой разумеющееся

3. vast – огромный

4. extensive – большой, протяженный

5. well-maintained – в хорошем состоянии

6. grumbling – ворчание

7. pothole – выбоина, рытвина, яма

8. traffic jam – затор в уличном движении, «пробка»

9. to pave – мостить

10. paved road – мощеная дорога

11. site – территория, площадка, строительная площадка

12. route – маршрут, путь

13. market outlet – рынок сбыта, торговая точка

14. to carry – нести, перевозить

15. to stretch – тянуться, простираться

16. to consume – потреблять

17. supplies – припасы, провиант

18. equipment – оборудование

19. engineer corps – инженерные войска

20. pontoon bridge – понтонный мост

21. to level – выравнивать

22. track – тропа, курс

23. cart – телега, повозка

24. siege engine – осадное орудие

25. stone – камень

 

Read the text, translate it and compare your ideas in ex.1 with the facts.

Roads. How it all started.

http://geofacts.ru/tajny-egipetskix-piramid/#

Most of us give very little thought to the roads we drive on every day, and tend to take them for granted – at least until they are closed for repairs, washed out in a flood and so on. However, only during the past forty years or so have we enjoyed the luxury of a vast, extensive, and well-maintained system of roads accessible to everyone. In the midst of our grumbling about potholes, traffic jams, and incompetent drivers, we forget how fortunate we truly are. Obviously, it was not always the case.

http://www.unmultimedia.org/radio/russian/archives/108878/

From the earliest times, one of the strongest indicators of a society’s level of development has been its road system – or lack of one. Increasing populations and the advent of towns and cities brought with it the need for communication and commerce between those growing population centres.

A road built in Egypt by the Pharaoh Cheops around 2500 BC is believed to be the earliest paved road on record – a construction road 1,000 yards long and 60 feet wide that led to the site of the Great Pyramid.

The various trade routes, of course, developed where goods were transported from their source to a market outlet and were often named after the goods which travelled upon them. For example, the Silk Route stretched 8,000 miles from China, across Asia, and then through Spain to the Atlantic Ocean. However, carrying bulky goods with slow animals over rough, unpaved roads was a time consuming and expensive. As a general rule, the price of the goods doubled for every 100 miles they had to travel.

Some other ancient roads were established by rulers and their armies. The Old Testament contains references to ancient roads like the King’s Highway, dating back to 2000 BC. This was a major route from Damascus in Palestine, and ran south to the Gulf of Aqaba, through Syria to Mesopotamia, and finally on to Egypt. Later it was renamed Trajan’s Road by the Romans, and was used in the eleventh and twelfth centuries by the Crusaders.

http://www.razlib.ru/istorija/mosty/p3.php

Around 1115 BC the Assyrian Empire in western Asia began what is believed to be the first organized road-building, and continued it for 500 to 600 years. Since they were trying to dominate that part of the world, they had to be able to move their armies effectively along with supplies and equipment. Their army’s engineer corps laid pontoon bridges and levelled tracks for carts and siege engines.

Later another imperial road, the Royal Road, was being built by the Persians from the Persian Gulf to the Aegean Sea, a distance of 1,775 miles. Around 800 BC, Carthage, on the northern coast of Africa, began to use stones for paving roads. Although they may not have been the first to pave their roads with stones, they were among the earliest, and some people believe that the Romans imitated Carthaginian techniques.

Source: http://www.triplenine.org/articles/roadbuilding.asp

 

Roman roads

http://pochemy.net/?n=559

Without doubt, the champion road builders were ancient Romans, who, until modern times, built the world’s straightest, best engineered, and most complex network of roads in the world. At their height, the Roman Empire maintained 53,000 miles of roads, which covered all of England to the north, most of Western Europe, radiated throughout the Iberian Peninsula, and encircled and crisscrossed the entire Mediterranean area. Famous for their straightness, Roman roads were composed of a soil foundation topped by four courses: a bedding of sand or mortar; rows of large, flat stones; a thin layer of gravel mixed with lime; and a thin surface of flint-like lava. Typically they were 3 to 5 feet thick and varied in width from 8 to 35 feet, although the average width for the main roads was from 12 to 24 feet. Their design remained the most sophisticated until the advent of modern road-building technology in the very late 18th and 19th centuries. Many of their original roads are still in use today, although they have been resurfaced numerous times.

http://ezhe.ru/ib/issue1008.html

Under Roman law, the public had the right to use the roads, but the district through which a road passed was responsible for the maintenance of the roadway. This system was effective so long as a strong central authority existed to enforce it. Unfortunately, as the Roman Empire declined so did their roads and their work fell into disrepair all across Europe and Great Britain.

South America

http://www.vseprokosmos.ru/golos34.html

On the other side of the Atlantic Ocean, several centuries after the fall of the Roman Empire, the Inca Empire began to rise in South America during a period that corresponded with the Middle Ages in Europe. Centred in what is now Peru, the Incas branched out into Ecuador, Colombia, Bolivia, Argentina, and Chile, and, like the Romans, recognized the need for a system of roads that would enable them to extend their conquests and to govern their empire. Interestingly enough, the Incas built their empire without inventing the wheel, without the use of draft animals, and without a written language. Because they had no wheeled vehicles to worry about, their roads could ascend steep inclines via terraces or steps.

http://anton-klyushev.livejournal.com/47998.html

In one place a road going up a steep mountainside was built of 3,000 consecutive stone steps. They also built over swamps, and constructed a causeway 24 feet wide and 8 miles long, which had a paved surface and stone walls. Unfortunately, their well-constructed system of roads assisted in their downfall as the invading Spaniards used the Incas’ own roads to move Spanish armies, weapons, and supplies.

Source: http://www.triplenine.org/articles/roadbuilding.asp

Conclusion

As they say, the rest is history – a history that most of us have experienced and just about any drive we take today provides concrete evidence of the outcome. Ironically, even at its height, American modern interstate highway system totals only about 42,500 miles (as of 1991). Granted, this figure does not include surface streets or other roads.

But 2,000 years ago the Romans, without the help of all our engineering technology or road-building machinery, constructed 53,000 miles of roads, much of which is still in use today.

I can’t help but wonder if our roads will be as impressive to historians 2,000 years from now.

Source: http://www.triplenine.org/articles/roadbuilding.asp

Right-of-Way.

http://stroitelstvo-new.ru/1/dorogi

The zone which is marked to lay the road is called the road zone or right-of-way. The higher is the technical classification of the road, the wider is the right-of-way for its construction. The road zone includes such parts of a road as a carriageway, road shoulders, inner and outer slopes, and other parts.

The road surface strip within the limits of which motor vehicles run is called a carriageway. Usually it is reinforced by means of natural or artificial stone aggregates. These stone aggregates form the pavement.

The strips of the ground which adjoin the carriageway are called the road shoulders. The shoulders render lateral support to the pavement. In future the pavement will always be made of solid materials within the limits of the carriageway.

To lay the carriageway at the required level above the ground surface a formation or roadbed is constructed. It is constructed in the form of embankments or cuttings with side ditches for drainage and the diversion of water.

The formation includes borrow pits – shallow excavations from which the soil was used for filling the embankments. It also includes spoil banks. Spoil banks are heaps of excessive soil remaining after the excavation of cuttings.

The carriageway and shoulders are separated from the neighbouring land by slopes. The cuttings and side ditches have inner and outer slopes. The junction of the surface of the shoulders and the embankment slope is called the edge of the roadbed. The distance between the edges is called the width of the roadbed.

Source: Английский язык. Контрольные задания. / Л.В. Лукина, Л.Н. Крячко, О.Ф. Нестерова,Н.В.Сидорова. Воронеж: Воронеж. гос. арх.-строит. ун.-т., 2009 – C.72

Pavement Structural Layers

To ensure all-year-round operation of vehicles traffic on a road, the carriageway is covered with a pavement. The pavement is laid on the surface of the roadbed. It can have rigid or semi-rigid structure. The pavement resists traffic stresses and climatic factors.

The stresses induced in the pavement by motor vehicle wheels attenuate with the depth. This enables the pavement to be designed in the form of a multilayer structure. The pavement consists of the following layers: the surfacing, the pavement base, the sub-base and the subgrade.

http://www.fhwa.dot.gov/engineering/geotech pubs/05037/03a.cfm

1. Surfacing is the upper and most rigid layer of the pavement. It is comparatively thin, but resists well the abrasion and the impacts caused by the wheels, and also the effect of weather conditions. Usually the surfacing is the most expensive part of the pavement. Surfacing usually comprises two coats or courses – a course and a wearing course. Surface course generally contains superior quality materials.

2. Below the surfacing base coat is the pavement base, a strong bearing layer of stony material or stone with a binding matrix. This layer is designed to distribute the individual wheel-loads. The pavement base is not subjected to the direct action of automobile wheels.

3. The sub-base is a layer of earth or stone materials, resistant to moisture, inserted when necessary between the pavement base and the roadbed. The sub-base is made of gravel, slag, soil treated with binding agents, sand, etc. Subbase is often the main load-bearing layer of the pavement. The primary functions of the sub-base are to provide structural support and improve drainage. The quality of subbase is very important for the useful life of the road.

4. The subgrade is the native material underneath a pavement. It comprises the thoroughly compacted upper layers of the roadbed upon which the layers of the pavement are laid. It is also called formation level.

Source: Английский язык. Контрольные задания. / Л.В. Лукина, Л.Н. Крячко, О.Ф. Нестерова,Н.В.Сидорова. Воронеж: Воронеж. гос. арх.-строит. ун.-т., 2009 – C.72-73

Side Ditches

For collecting water from the roadbed side ditches, flumes, interceptor ditches and drain channeling can be used. Present road construction provides side ditches parallel with the roadway. A side ditch is intended to collect the water discharged by the crown. It also collects the water from the roadside. Water from the adjoining land must be collected by the side ditch too. The side ditch discharges into a natural outlet at the first opportunity.

Side ditches in cuttings and next to embankments may be excavated to a depth of up to 0.6 m. These ditches are for the collection of water flowing off the road surface and from adjoining land during rainfall or snow thawing. The side ditch may contribute to the drainage of the subgrade because of the evaporation of moisture from the side ditch inner slopes. However, the major use of the side ditch is to permit the rapid discharge of water. When this water discharge is not ensured and ponding occurs, the side ditch becomes a source from which water may penetrate back under the road, resulting in saturation of the subgrade.

http://www.fao.org/docrep/006/t0099e/t0099e04.htm

The cross-section of the ditch is either V-typed (triangular) or trapezoidal. In the case of impermeable soils and in less favorable conditions of runoff the side ditches can be given a trapezoidal cross-section with a bottom width of 0.4 m and a depth of up to 0.7-0.8 m from the edge embankment. If the road must be built in dry country with a rapid surface runoff, and the occurrence of ground water is deep, the side ditches are given the shape of triangular flues of 0.3 m minimum depth. The V-typed side ditch can be easily constructed and maintained with the blade grader. The V-typed side ditch cannot be deep and, therefore, it is much safer than the trapezoidal side ditch.

Source: Английский язык. Контрольные задания. / Л.В. Лукина, Л.Н. Крячко, О.Ф. Нестерова, Н.В.Сидорова. Воронеж: Воронеж. гос. арх.-строит. ун.-т., 2009 – C.73-74

UNIT 3: TYPES OF PAVEMENT

1. Before you start. · What do we call a pavement? · What structural layers of pavement do you remember?

Circle the odd word.

1.	rigid	subgrade	subbase	base
2.	concrete	asphalt	gravel	maintenance
3.	cost	economic growth	passengers	investment
4.	pavement	chemicals	road network	road surface
5.	repair	rehabilitation	maintenance	cobblestone

 

Asphalt

Asphalt (specifically, asphalt concrete) has been widely used since the 1920s. Most asphalt surfaces are laid on a gravel base, which is generally at least as thick as the asphalt layer, although some asphalt surfaces are laid directly on the native subgrade.

http://rollacity.blogspot.ru/2012/09/city-of-rolla-weekend-e-updates-sept-21.html

Depending on the temperature at which it is applied, asphalt is categorized as hot mix, warm mix and cold mix. Cold mix asphalt is often used on lower volume rural roads, where hot mix asphalt would cool too much on the long trip from the asphalt plant to the construction site.

An asphalt concrete surface will generally be constructed for high volume primary highways having an average annual daily traffic load greater than 1200 vehicles per day. Advantages of asphalt roadways include relatively low noise, relatively low cost compared with other paving methods, and perceived ease of repair. Disadvantages include less durability than other paving methods, less tensile strength than concrete, the tendency to become slick and soft in hot weather and a certain amount of hydrocarbon pollution to soil and groundwater.

Source: http://en.wikipedia.org/wiki/Asphalt_concrete

Concrete

Concrete surfaces (specifically, PCC) are usually used on roads with heavy traffic of heavy vehicles and created using a concrete mix of Portland cement, coarse aggregate, sand and water. In virtually all modern mixes there will also be various admixtures added to increase workability, reduce the required amount of water, mitigate harmful chemical reactions and for other beneficial purposes. In many cases there will also be Portland cement substitutes added, such as fly ash. This can reduce the cost of the concrete and improve its physical properties.

Concrete surfaces are divided into three common types: jointed plain (JPCP), jointed reinforced (JRCP) and continuously reinforced (CRCP). Each of the jointing system types is used to control crack development.

http://dc261.4shared.com/doc/W3tVqUxD/preview.html

Jointed plain concrete pavement is the most common type of rigid pavement. JPCP controls cracks by dividing the pavement up into individual slabs separated by contraction joints. JPCP does not use any reinforcing steel but uses dowel bars and tie bars. Today the majority of US state agencies build jointed plain pavements.

Jointed reinforced concrete pavements control cracks by dividing the pavement up into individual slabs separated by contraction joints. However, these slabs are much longer than JPCP slabs, so JRCP uses reinforcing steel within each slab to control within-slab cracking. Today very few of agencies use this design, because it is not recommended as both of the other types offer better performance and are easier to repair.

Continuously reinforced concrete pavements use reinforcing steel rather than contraction joints for crack control. Cracks are held tightly together by the underlying reinforcing steel. A number of agencies have made decisions to use continuously reinforced designs in their heavy urban traffic corridors.

One of the major advantages of concrete pavements is that they are typically stronger and more durable than asphalt roadways. They can also provide a durable skid-resistant surface. A notable disadvantage is that it can typically have a higher initial cost, as well as can be more time consuming to construct. This cost can typically be offset through the long life cycle of the pavement.

Source: http://en.wikipedia.org/wiki/Road_surface

Other pavements

Composite surface combines Portland cement concrete and asphalt. They are usually used to rehabilitate existing roadways rather than in new construction.

http://www.forconstructionpros.com/article/10616882/clearing-the-air-about-pneumatic-rollers

Bituminous surface treatment (BST) is used mainly on low-traffic roads, but also as a sealing coat to rejuvenate an asphalt concrete pavement. It generally consists of aggregate spread over a sprayed on asphalt emulsion or cut-back asphalt cement. The aggregate is then embedded into the asphalt by rolling it, typically with a rubber-tired roller. This type of surface is described by a wide variety of regional terms including "chip seal", "oil and stone" etc.

The ease of application of BST is one reason for its popularity, but another is its flexibility, which is important when roadways are laid down over unstable terrain that thaws and softens in the spring.

http://commons.wikimedia.org/wiki/File:Gravel_Road_Coober_Pedy.jpg

Gravel is known to have been used extensively in the construction of roads by soldiers of the Roman Empire. A granular surface can be used with a traffic volume where the average annual daily traffic is 1,200 vehicles per day or less. There is some structural strength as the road surface combines a sub base and base and is topped with a seal aggregate with emulsion. The decision whether to pave a gravel road or not often depends on traffic volume. Obviously, it is not as durable as concrete or asphalt pavements, but relatively cheap.

Pavers generally have the form of pre-cast concrete blocks, are often used for aesthetic purposes. Pavers are rarely used in areas with high-speed vehicle traffic.

en.wikipedia.org/wiki/Road_surface

http://en.wikipedia.org/wiki/Road_surface

Brick, cobblestone, sett pavements were once common in urban areas throughout the world, but fell out of fashion in most countries, due to the high cost of labor required to lay and maintain them, and are typically only kept for historical or aesthetic reasons. In some countries, however, they are still common in local streets.

Source: http://en.wikipedia.org/wiki/Road_surface

Circle the odd word.

1.	bituminous surface treatment	rubber-tired roller	gravel surface	pavers
2.	concrete	asphalt	gravel	chemical reactions
3.	brick	sett	composite surface	cobblestone
4.	sand	properties	water	Portland cement
5.	continuously reinforced concrete pavement	jointed reinforced concrete pavement	maintenance	jointed plain concrete pavement

 

Step I: Planning

A road project begins with evaluating the transportation system, taking into account statewide priorities, including strategic plans for the state’s transportation system. Department of Transportation collects and maintains information about our roads, including road and bridge conditions, traffic volumes, crash statistics.

Using this data, transportation planners, engineers, environmentalists, landscape architects, soil scientists and others identify trends that determine what and how to build.

http://www.michigan.gov/mdot/0,1607,7-151-9615-129011--,00.html

Step II. Design

A survey of the area is step two. Recently, Global Positioning Systems, laser surveys, and other technology have sped up the process and improved accuracy. Many factors influence designs, including location, terrain and soil properties, drainage capabilities, traffic volume, the ratio of cars to trucks and buses, possible future development in the area, effects on the environment or nearby residents.

Step III. Earthwork

Earthwork is one of the most important elements in road construction because it establishes a stable foundation. The aim of the earthworks phase of the construction is to position the subgrade underlying the pavement layers in the right location and at the correct level and to provide drainage.

http://www.michigan.gov/mdot/0,1607,7-151-9615-129011--,00.html

First, embankments are built. Next, a grader or bulldozer levels the screened dirt. Leveling bumps and filling in dips creates a surface that will support a road for decades. The screened dirt is sprayed with water and compacted to its maximum density. During this stage, drains and sewers are installed. The center of the road must be higher than the edges so water will run off into the storm sewers. Drainage is a critical element because improper drainage will greatly reduce the new pavement’s life expectancy. All of this work must pass strict inspections before the project can continue. To complete the earthwork, workers place gravel in 12-inch layers on the road bed, then moisten and compact each layer. Layers are added and compacted until the road bed reaches the height called for in the design.

The earthwork is often the largest task in the road building process and therefore careful planning and organization are essential. Speed and efficiency depend very much upon the quantity and types of earthmoving plant available.

Source: http://www.michigan.gov/mdot/0,1607,7-151-9615-129011--,00.html

Construction activities

Step IV. Pavement Construction

http://www.michigan.gov/mdot/0,1607,7-151-9615-129011--,00.html

At last, the road bed is ready for paving. Planners and engineers study such factors as the cost of maintaining the road, the amount and type of traffic, the cost of paving material.

A formula that includes all these factors tells engineers to use either asphalt (bituminous) or concrete pavement.

Asphalt uses bitumen, a petroleum product, to glue together sand and crushed rock. This mixture is heated to approximately 300 degrees at the asphalt plant. At the construction site, workers spread and compact the hot mixture onto the roadbed.

Concrete uses cement and water as the glue between sand and crushed rock. Workers place concrete into steel molds called forms. A finishing machine vibrates and trims it to the necessary height. To prevent cracks, workers cut joints between the concrete slabs.

At each joint, wire baskets and steel dowels connect the slabs. These allow the slabs to expand and contract as the temperature changes. The slabs can slide from side to side along the dowels, but not up and down.

Step V. Open to traffic

With the new surface in place, quality testing is conducted. Testers use seismology equipment to measure vibrations of the new pavement. If there is too much vibration, the contractor must grind the pavement to ensure a smooth surface. The final steps are:

· another drainage test;

·

http://www.michigan.gov/mdot/0,1607,7-151-9615-129011--,00.html

grading and landscaping around the pavement (where applicable);

· applying the permanent pavement markings.

Source: http://www.michigan.gov/mdot/0,1607,7-151-9615-129011--,00.html

 

UNIT 1: TRAFFIC SIGNS

1. Before you start. · What is the purpose of traffic signs? · What traffic signs do you know?

Road signs

http://www.liveinternet.ru/users/cdefg/post181491573/

Traffic signs or road signs are signs erected at the side of or above roads to give instructions or provide information to road users. The earliest road signs were milestones, giving distance or direction; for example, the Romans erected stone columns throughout their empire giving the distance to Rome.

In the Middle Ages, multidirectional signs at intersections became common, giving directions to cities and towns.

http://fotki.yandex.ru/

The first modern road signs erected on a wide scale were designed for riders of high or “ordinary” bicycles in the late 1870s and early 1880s. With traffic volumes increasing since the 1930s, many countries have adopted pictorial signs or otherwise simplified and standardized their signs to overcome language barriers, and enhance traffic safety. Such pictorial signs use symbols in place of words and are usually based on international protocols. Such signs were first developed in Europe, and have been adopted by most countries to varying degrees. Pre-industrial signs were stone or wood. In the late 18th and 19th centuries painted cast iron became popular. Since 1945 most signs have been made from sheet aluminium with adhesive plastic coatings, these are normally retroreflective for night-time and low-light visibility. Before the development of reflective plastics, reflectivity was provided by glass reflectors set into the lettering and symbols.

New generations of traffic signs based on electronic displays can also change their text (or, in some countries, symbols) to provide for “intelligent control” linked to automated traffic sensors.

http://autokadabra.ru/shouts/61302

Traffic signs can be grouped into several types. For example, Annexe 1 of the Vienna Convention on Road Signs and Signals (1968), which on 30 June 2004 had 52 signatory countries, defines eight categories of signs:

A. Danger warning signs

B. Priority signs

C. Prohibitory or restrictive signs

D. Mandatory signs

E. Special regulation signs

http://www.pametka.ru/story.php?title=SVETODIODNYE-DOROZHNYE-ZNAKI-OT-PROIZVODITELYA-PO-NIZKIM-TSENAM

F. Information, facilities, or service signs

G. Direction, position, or indication signs

H. Additional panels

Units

Distances on traffic signs generally follow the measurement system in use by the country. Most US road signs use miles or feet, although the Federal Department of Transportation has developed metric standards for all signs. The United Kingdom signs also display distances in miles. Elsewhere, metric distances are in very wide use, though not universal.

Languages

Where signs use a language, the recognized languages of the area is normally used. Signs in most of the US, Canada, Australia, and New Zealand are in English. Quebec uses French, while, in Montreal and some other Canadian provinces use both English and French, a territory of the US, Mexico, and Spain use Spanish. Within a few miles of the US–Mexico border, road signs are often in English and Spanish in places like San Diego.

Source: http://en.wikipedia.org/wiki/Traffic_sign

Circle the odd word.

1.	cast iron	sheet aluminium	stone	glass
2.	measurement system	metric standard	mandatory sign	metric distance
3.	traffic (road) sign	directional arm	fingerpost	direction
4.	visibility	traffic volume	road quality	retroreflective

UNIT 2: TRAFFIC CONTROL

1. Before you start. · Are there any congestions in your city? · Do the authorities try to solve the problem of congestion?

Traffic control

It is obvious that in existing urban areas much of the congestion is due to narrow streets and junctions which are incapable of taking peak-hour traffic. The solutions of this problem are costly. They include adequate roundabouts and street widening and the segregation of traffic by means of flyover roads, underpasses, bridges and pedestrian subways.

Much of the congestion in urban areas is due to traffic which has no business in the area but is only passing through.

http://blog.william-russell.com/beijings-plan-to-introduce-congestion-charge-to-ease-traffic-problems/

There is a tendency for drivers to keep to the well-lit shopping streets. If they can be made to use less important streets and those not occupied by shops, then conditions are improved not only for the through traffic but also for the local traffic.

Signposting is, of course, a directional control and a very effective one. In fact it is important for all signs and symbols used on the roads to be seen well in advance by drivers approaching at normal speed. Directional control cannot increase the capacity of the highway system but it can avoid local congestion.

One-way traffic is a special kind of directional control which is very effective in maintaining the traffic flow in congested areas.

A major cause of congestion in towns is the interruption to the free flow of traffic by cross traffic at junctions. But if the need for traffic streams to cross each other can be avoided then the movement of vehicles will be much easier. This easier movement of traffic can often be achieved by making traffic move in one direction only along certain streets and by prohibiting incoming vehicles from side streets from crossing the main stream. The streets may be either one-way or two-way according to local conditions of traffic or width of carriageway, and traffic at the junctions can be guided by constructing suitably-shaped islands. Besides, one-way traffic can also be introduced where the carriageway width is inadequate for two opposing lines of traffic.

http://www.esi.info/detail.cfm/Sustainable-Options/Recycled-plastic-finger-signposts/_/R-40765_LS90RQ

The disadvantages of a one-way traffic system are that it increases the distance travelled by some vehicles, that it makes it more difficult for strangers to find their way about. The true aim of a one-way system is to eliminate cross traffic, and under conditions of continuous flow on crossing streets the introduction of a properly designed one-way scheme can double the carrying capacity of the highways.

The two main objections to street intersections are that they are a cause of accidents and that they interrupt the flow of traffic. The best thing to do with intersections is to get rid of them. If that is not possible they may be improved and made safer but they will always remain a source of danger and delay.

Many accidents are caused because traffic streams of different types, or traffic streams travelling in different directions are using the same carriageway, and these accidents can be avoided either by reservations between traffic lanes, or by vertical (or “grade”) separation.

In many cities in America and in Europe segregation of traffic is achieved by means of flyovers or underpasses; at some junctions there are even three different levels. Each has its advantages and disadvantages according to the cir­cumstances. Flyover structures are not always aesthetically pleasing while an underpass may be more expensive to construct. The separation of fast and slow traffic from the heavier and faster traffic is most desirable not only in the interests of freedom of traffic movement, but also of safety. This ideal is not easy to achieve.

Urban traffic control will be of benefit to the general public in the district concerned and will result in greater comfort for road users of all classes, as well as bringing economic advantages to the community as a whole.

Source: Пособие по английскому языку для студентов II-III курсов строительных вузов / М.: Высш. школа, 1978. – C.27-29

UNIT 3: ROAD SAFETY

1. Before you start. · Are Russian roads safe? · Do road signs help to increase road safety?

Road safety

Road traffic safety refers to methods and measures for reducing the risk of a person using the road network being killed or seriously injured. The users of a road include pedestrians, cyclists, motorists, their passengers, and passengers of on-road public transport, mainly buses and trams. Best-practice road safety strategies focus upon the prevention of serious injury and death crashes in spite of human fallibility. Safe road design is now about providing a road environment which ensures vehicle speeds will be within the human tolerances for serious injury and death wherever conflict points exist.

http://www.otradny-13sad.ru/index/profilaktika_detskogo_dorozhno_transportnogo_travmatizma/0-50

On existing urban roads where many vulnerable road users, such as pedestrians and bicyclists can be found, traffic calming can be a tool for road safety. Though not strictly a traffic calming measure, mini-traffic circles implanted in existing, normal intersections of urban streets, have been shown to reduce collisions at intersections dramatically. Shared space schemes, which rely on human instincts and interactions, such as eye contact, for their effectiveness, and are characterised by the removal of traditional traffic signals and signs, and even by the removal of the distinction between roadway and footway, are also becoming increasingly popular. Both approaches can be shown to be effective.

Major highways are designed for safer high-speed operation and generally have lower levels of injury per vehicle km than other roads.

Safety features include:

· Limited access from properties and local roads.

· Grade separated junctions

· Median dividers between opposite-direction traffic to reduce likelihood of head-on collisions

· Removing roadside obstacles.

·

http://kevah.ru/photo/trodden_path.html

Prohibition of more vulnerable road users and slower vehicles.

Modern safety barriers are designed to absorb impact energy and minimize the risk to the occupants of cars, and bystanders. For example some road fixtures such as road signs and fire hydrants are designed to collapse on impact. Highway authorities have also removed trees in the vicinity of roads; while the idea of “dangerous trees” has attracted a certain amount of skepticism, unforgiving objects such as trees can cause severe damage and injury to any road users.

Source: http://en.wikipedia.org/wiki/Road_traffic_safety

Road surface markings

Road surface marking is a kind of device or material used on a road surface in order to convey official information. They can also be applied to mark parking spaces or areas for other uses.

http://www.roadsafeco.com.au/

Road surface markings provide guidance and information to drivers and pedestrians. Uniformity of the markings is an important factor in minimizing confusion about their meaning. However, countries and areas categorize and specify road surface markings in different ways.

Road surface markings can be mechanical, non-mechanical, or temporary.

Mechanical devices may be raised into the road surface. They are either reflective or non-reflective. Most are permanent; some are movable.

Cat’s eyes equip most major routes in the British Isles. They consist of four reflective lenses mounted in durable white rubber housing, two facing fore and two facing aft. The lenses are available in a variety of different colours, mainly white, yellow, orange, green, red and blue.

http://www.commercialmotor.com/big-lorry-blog/solarlites-cats-eye-saves-lives

http://www.reflective-safety.com/snoline-polystud.html

Botts’ dots are round non-reflective raised pavement markers named after California Department of Transportation engineer Elbert Botts, who invented the epoxy that keeps them glued down. Generally they are used to mark the edges of traffic lanes often together with reflective raised pavement markers. They are used only in warm climates since snow plows usually remove them along with the snow.

A rumble strip is usually either applied in the direction of travel along an edge- or centerline to alert drivers when they drift from their lane, or in a series across the direction of travel to warn drivers of a stop ahead or nearby danger spot. In favorable circumstances rumble strips are effective (and cost-effective) at reducing accidents due to inattention.

http://paulpetersoncompany.com/news/blog/

Reflective markers are used as lane dividers to mark the central reservation. They are typically more visible at night than standard road marking lines. The color of markers varies depending on the country of use. Reflective markers are also referred to as raised pavement markers. In the United Kingdom and elsewhere, raised markers are used to mark crossings to assist the blind in crossing streets. In colder climates reflective markers may be installed below ground.

Non-mechanical markers

Paint is generally used to mark traffic lanes, spaces in parking lots or special purpose spaces for disabled parking. Colors for these applications vary by locality. Paint is usually applied right after the road has been paved. The road is marked commonly by a truck called a “striper”. These trucks contain hundreds of gallons of paint stored in huge drums. The markings are controlled manually or automatically by the controller.

Thermoplastic is one of the most common types of road marking. The main advantages of thermoplastic are durability and retro-reflectivity. Most thermoplastic is produced in white and yellow colours.

http://www.roadtraffic-technology.com/contractors/road_marking/kadcam/

Plastic is used to mark crossroads, stop bars, and traffic guidance such as turn lanes, train crossings, pedestrian crossings, taxi lanes, bus and bike lanes.

Pylons are sometimes used to separate HOV lanes from regular traffic lanes.

Source: http://en.wikipedia.org/wiki/Road_surface_marking

Circle the odd word.

1.	Bott’s dots	uniformity	cat’s eyes	rumble strip
2.	mechanical	non-mechanical	temporary	route
3.	striper	pedestrian	driver	bicyclist
4.	paint	plastic	thermoplastic	confusion
5.	bus lane	pedestrian crossing	turn lane	durability

History of bridges

The first bridges were made by nature itself – as simple as a log fallen across a stream or stones in the river. The first bridges made by humans were probably spans of cut wooden logs or eventually stones, using a simple support and crossbeam arrangement. Some early Americans used trees or bamboo poles to cross small wells to get from one place to another. A common form of sticks, logs, and deciduous branches together involved the use of long fibres woven together to form a rope used for binding and holding together the materials used in early bridges.

http://ru.advisor.travel/poi/Arkadiko-Bridge-12306

The Arkadiko Bridge is one of four Mycenaean arch bridges, part of a former network of roads in Greece. Dating to the Greek Bronze Age (13th century BC), it is one of the oldest arch bridges still in existence and use. Several intact arched stone bridges from the Hellenistic era can be found in the Peloponnese in southern Greece.

The greatest bridge builders of antiquity were the ancient Romans. The Romans built arch bridges and aqueducts that could stand in conditions that would damage or destroy earlier designs. Some stand today. An example is the Alcántara Bridge, built over the river Tagus, in Spain. The Romans also used cement, which reduced the variation of strength found in natural stone. One type of cement, called pozzolana, consisted of water, lime, sand, and volcanic rock. Brick and mortar bridges were built after the Roman era, as the technology for cement was lost then later rediscovered.

Alcántara Bridge

An ancient Indian treatise mentions the construction of dams and bridges. The use of stronger bridges using plaited (переплетенный) bamboo and iron chain was visible in India by about the 4th century. A number of bridges, both for military and commercial purposes, were constructed by the Mughal administration in India.

Although large Chinese bridges of wooden construction existed at the time of the Warring States (476-221 BC), the oldest surviving stone bridge in China is the Zhaozhou Bridge, built from 595 to 605 AD.

Rope bridges, a simple type of suspension bridge, were used by the Inca civilization in the Andes Mountains of South America, just prior to European colonization in the 16th century.

http://www.history.ucsb.edu/faculty/marcuse/classes/2c/2c06/lectures/06L03IndRev.htm

During the 18th century there were many innovations in the design of timber bridges by Hans Ulrich, Johannes Grubenmann, and others. The first book on bridge engineering was written by Hubert Gautier in 1716. A major breakthrough in bridge technology came with the erection of the Iron Bridge in Coalbrookdale, England in 1779. It used cast iron for the first time as arches to cross the river Severn.

With the Industrial Revolution in the 19th century, truss systems of wrought iron were developed for larger bridges, but iron did not have the tensile strength to support large loads. With the advent of steel, which has a high tensile strength, much larger bridges were built, many using the ideas of Gustave Eiffel.

In 1927 welding pioneer Stefan Bryła designed the first welded road bridge in the world.

Source: http://en.wikipedia.org/wiki/Bridge#History

UNIT 2: TYPES OF BRIDGES

1. Before you start. · What is a bridge? · How many types of bridges do you think exist?

Beam type

The four main factors are used in describing a bridge. By combining these terms one may give a general description of most bridge types:

· span (simple, continuous, cantilever),

· material (stone, concrete, metal, etc.),

· placement of the travel surface in relation to the structure (deck, pony, through),

· form (beam, arch, truss, etc.).

The three basic types of spans are shown below. Any of these spans may be constructed using beams, girders or trusses. Arch bridges are either simple or continuous. A cantilever bridge may also include a suspended span.

http://pghbridges.com/basics.htm

Examples of the three common travel surface configurations are shown in the truss type drawings below. In a deck configuration, traffic travels on top of the main structure; in a pony configuration, traffic travels between parallel superstructures which are not cross-braced at the top; in a through configuration, traffic travels through the superstructure (usually a truss) which is cross-braced above and below the traffic.

http://pghbridges.com/basics.htm

Simple deck beam bridges are usually metal or reinforced concrete. Other beam and girder types are constructed of metal. The end section of the two deck configuration shows the cross-bracing commonly used between beams. The pony end section shows knee braces which prevent deflection where the girders and deck meet.

http://pghbridges.com/basics.htm

http://pghbridges.com/basics.htm

One method of increasing a girder’s load capacity while minimizing its web depth is to add haunches at the supported ends. Usually the center section is a standard shape with parallel flanges; curved ends are riveted using splice plates.

Many modern bridges use new designs developed using computer stress analysis. The rigid frame type has superstructure and substructure which are integrated. Commonly, the legs and deck are a single piece which is riveted to other sections.

http://pghbridges.com/basics.htm

Source: http://pghbridges.com/basics.htm

Arch types

Arch bridge is one of the most popular types of bridges, which came into use over 3000 years ago and remained in height of popularity until industrial revolution and invention of advanced materials enabled architect to create other modern bridge designs. However, even today arch bridges remain in use, and with the help of modern materials arches can be build on much larger scales.

The basic principle of arch bridge is its curved design. Abutments carry the load of the bridge and are responsible for holding the arch in the unmoving position.

http://www.aiacincinnati.org/community/abc/

Also the type of connections used at the supports and the midpoint of the arch may be used – counting the number of hinges which allow the structure to respond to stresses and loads.

http://pghbridges.com/basics.htm

Arch configuration is another method of classification. Examples of tied arch, trussed arch and spandrel-braced arches are shown. A tied arch is commonly constructed using curved girder sections. A trussed arch has a curved through truss rising above the deck. A spandrel-braced arch carries the deck on top of the arch.

http://pghbridges.com/basics.htm

Arch bridges rely on vertical members to convey the load carried by the arch.

Source: http://www.aiacincinnati.org/community/abc/curriculum/fivebridgetypes.pdf

Truss types

Trusses work much like beams: they carry a combination of compression and tension forces. The main difference is that trusses are less heavy than beams. Beams use extra material in some areas; these areas don’t use the full strength available to them. Engineers and builders can determine which portions of beams can be removed. The resulting truss concentrates the forces into many smaller members and eliminates the under-stressed areas of beams.

A truss is made of many smaller parts. Once constructed of wooden timbers, and later including iron members, most truss bridges are built of metal. As for the placement of the travel surface in relation to the superstructure truss bridges are divided into king and queen post trusses. The king post consists of two an