2132

10. Study the table and try to guess what interchange is told about in the sentences given below the table:

1)This interchange joining up with another highway, creates two highways in one direction.

2)This interchange can be useful for toll roads.

3)This interchange doesn’t require large amount of land.

4)This interchange requires three levels.

5)This interchange is used when a three-way interchange is required for two highways interchanging in right-angle way.

6)This type of interchange is often used for bypass routes.

7)The shape of this interchange resembles the letter “Y”. But it has only exit ramps.

8)This interchange differs from its full variant in amount of loop ramps and in construction of directional ramps.

11.Using sources of internet find information about interchanges between a highway and non-highway road and compete interchanges. Present the results of your survey using PowerPoint. (Project work)

12.Skim the following text. Make up a scheme devoted to the classification of intersections and describe it orally. Find out what the main distinction between interchanges and intersections is.

INTERSECTIONS

In the field of road transport, an intersection is a road junction where two or more roads either meet or cross at grade (they are at the same level). Such a road junction may also be called a crossroads.

Some may classify intersections as 3-way, 4-way, 5-way, 6-way, etc. depending on the number of road segments (arms) that come together at the intersection.

A junction between three road segments

(arms) (3-way intersection) is a T junction (two arms form one road or a Y- junction.

4-way intersections are the most common, because they usually involve a crossing over of two streets or roads. In areas where there are blocks and in some other cases, the crossing streets or roads are perpendicular to each other. However, two roads may cross at a different angle.

5-way intersections are less common but still exist, especially in urban areas with non-rectangular blocks.

6-way intersections usually involve a crossing of three streets at one junction; for example, a crossing of two perpendicular streets and a diagonal street is a rather common type of 6-way intersection.

Seven or more such segments coming together at a single intersection are

rare.

Another way of classifying intersections is by traffic control: Uncontrolled intersections, without signs or signals (or sometimes with a

warning sign). Priority rules may vary by country: on a 4-way intersection traffic from the right often has priority; on a 3-way intersection either traffic from the right has priority again, or traffic on the continuing road. For traffic coming from the same or opposite direction, that which goes straight has priority over that which turns off.

Yield-controlled intersections may or may not have specific “YIELD” signs (known as “GIVE WAY” signs in some countries).

Stop-controlled intersections have one or more “STOP” signs. Two-way stops are common, while some countries also employ four-way stops.

Signal-controlled intersections depend on traffic signals, usually electric, which indicate which traffic is allowed to proceed at any particular time.

A traffic circle is a type of intersection at which traffic streams are directed around a circle. Types of traffic circles include roundabouts, “miniroundabouts”, “rotaries”, “STOP”-controlled circles, and signal-controlled circles. Some people consider roundabouts to be a distinct type of intersection from traffic circles (with the distinction based on certain differences in size and engineering).

A box junction can be added to an intersection, generally prohibiting entry to the intersection unless the exit is clear.

13. Look through the text. There are some mistakes connected with derivation in it. Find them and correct.

TRAFFIC CIRCLES

A traffic circle or rotary is a type of circular intersection in which traffic must travel in one direction around a centrality island. In some countries, traffic entered the circle has the right-of-way and drivers in the circle must yield. Other common characteristics include large diameters (over 100 m or 300 ft) and minimal horizontal deflect so as to facilitate speeds of 50 km/h (30 mph) or more.

Traffic circles should not be confused with roundabouts, in which entering traffic must always yield to traffic already in the circle, and general operate at much lower speeds.

The term “traffic circle” is used to describe circular intersections that have the following characteristics:

Often, circulating traffic yields to entering traffic at one or more approachable points.

Tangential approaches between approach roadways and the circulatory roadway allow full-speed entry. Conversely, some traffic circles do not have channelizing approaches at all, and roads intersect the circles at 90 degree angles.

High circulating speeds (over 30 mph / 50 km/h) mean that large gaps are needed in the circulating traffic to allow stopped vehicles to safely enter, resulting in lower capacitors and higher crash rates than modern roundabouts.

Lane changes may be made within circle road.

The circles are generally of a very large diameter.

There is sometimes pedestrian access to the center island, or parking on the circle.

French architect Eugène Hénard was designing one-way circular intersections as early as 1877. American architectural William Phelps Eno favored small traffic circles. He designed New York City’s famous Columbus Circle, which was built in 1905. Other circular intersections were subsequent built in the United States, though many were large diameter “rotaries” that enabled high speed merge and weave maneuvers. These designs were doom to failure for two primary reasons:

It takes a large diameter circle to provide enough room for merging at speed. Although some of these circles were huge (many were in excess of 100 meters or 300 feet in diameter), they weren't large enough for high-speed merging.

Giving priority to entering traffic means that more vehicles can enter the circulatory roadway than it can handle. The result is congestion within the circle which could not clear without police interventional.

The experience with traffic circles and rotaries in the US was almost entirely negative, characterized by high accident rates and congestion problems. By the mid 1950s, construction of traffic circles and rotaries had ceased entirely. The experience with traffic circles in other countries was not much better until the development of the modern roundabout in the United Kingdom during the 1960s.

14.Unscramble the following words and give explanation to their meanings:

adroyaw, taroyr, ciacdent, licolnois, terinsecnoit, boeastdnu.

15. Read the text and match the following statements with each paragraph.

1)If an arrow marking traffic lane is double-headed it indicates that vehicles can travel in two directions.

2)Vehicles may enter the intersection to turn left only when there is a green light facing them.

3)Turns are usually regulated at same-grade intersections.

4)Turn lanes can reduce accidents considerably.

5)If there are no left turn lanes many other combinations of traffic signals are used.

TURNS

At same-grade intersections, turns are usually allowed, but often regulated to avoid interference or collision with other traffic. If the crossing street is a one-way street, a turn into the opposing direction is not allowed, as indicated by “ONE WAY” or “NO LEFT TURN” or “NO RIGHT TURN” signs. In a few other cases, certain turns may be not allowed or limited by regulatory signs or signals, such as a sign saying “NO TURN ON RED” (no turn allowed when a red light is on). In the absence of lane markings indicating otherwise, left turns should be made from the leftmost lane and right turns from the rightmost lane to avoid collision or blocking of traffic going straight.

 At some intersections where vehicles travel on the right side of the road, there are left turn lanes where the street/road approaches the intersection. For example in the intersection shown in the following diagram, there are left turn lanes in the east-west street for traffic approaching the intersection in the eastbound and westbound directions.

These left turn lanes are marked with an arrow bending into the direction of the left turn which is to be made from that lane only. The word “ONLY” in those lanes means that vehicles may only use them to make a left turn from there. In some other cases, a double-headed arrow may indicate vehicles may travel in either one of two directions from that lane.

Traffic signals facing vehicles in left turn lanes often have a special green left turn arrow, indicating vehicles may turn left unhindered by oncoming traffic when this green arrow light is on. Even though the north-south street does not have left turn lanes, traffic may still turn left (unless otherwise not allowed) from the leftmost lane facing the intersection northbound or southbound. When there is no green left turn arrow, vehicles from that direction may enter the intersection to turn left only when there is a green light facing them and must yield to all oncoming traffic.

There are intersections with no left turn lanes and many major intersections with left turn lanes for traffic from all directions. Streets without left turn lanes usually either have less traffic than streets with left turn lanes or are older streets where it is difficult to widen the street to accommodate the extra lane. Depending on the intersection, many other combinations of traffic signals (such as green, yellow, or red left or right arrows) and left or right turn lanes are possible. In areas where vehicles travel on the left side of the road, the preceding discussion about left turns applies to right turns instead. Often parallel parking on the side of a street is not allowed close to an intersection to allow traffic to flow through better near the intersection.

Turn lanes can have a dramatic effect on the safety of a junction. In rural areas, crash frequency can be reduced by up to 48% if left turn lanes are provided on both main-road approaches at stop-controlled intersections. At signalized intersections, crashes can be reduced by 33%. Results will be slightly lower in urban areas.

16.Using information from this part say if the following statements are true or false, correct false statements:

1)A traffic circle or rotary is a type of circular intersection in which traffic travel in two directions around a central island.

2)French architect Eugène Hénard designed one-way circular intersections in 1867.

3)High circulating speeds of transport result in higher crash rates.

4)At same-grade intersections turns are usually allowed, but often regulated.

5)Because of high accident rates and congestion problems traffic circles and rotaries in the US were replaced with roundabouts.

6)A traffic circle is a type of intersection at which traffic streams are directed around a circle.

7)An intersection is a road junction where two or more roads either meet or cross at different grades.

8)Trumpet interchanges are named as such due to their resemblance to trumpets.

9)Full Y-interchanges require a considerable amount of land and money.

10)An interchange is a road junction that typically uses grade separation to permit traffic to pass through the junction without directly crossing any other traffic stream.

17.Change this writing into the text and title it:

Numerouscircularjunctionsexistedbeforetheadventofroundaboutsincludingt heColumbusCircleinNewYorkCityandseveralcircleswithinWashingtonDCHowe vertheoperatingandentrycharacteristicsofthesecirclesdifferedconsiderablyfromm odernroundaboutsThefirstBritishroundaboutwasbuiltinLetchworthGardenCityin1 909originallyintendedpartlyasatrafficislandforpedestriansIntheearly20thcenturyn umeroustrafficcirclejunctionswereconstructedintheUnitedStatesparticularlyinthe northeaststateswhichallowentryatrelativelyhighspeedsandrequireenteringdriverst oweavewithexitingandcirculatingtraffic

HoweverthewidespreaduseofroundaboutsbeganwhenBritishengineersreengi neeredcircularintersectionsduringthemid-1960sandFrankBlackmoreinventedthem iniroundabouttoovercomeitslimitationsofcapacityandforsafetyissuesUnliketraffic circlestrafficapproachingroundaboutsisnormallyrequiredtogiveprioritytocirculati ngandexitingtrafficandtoeliminatemuchofthedriverconfusionassociatedwithtraffi ccirclesandwaitingqueuesassociatedwithjunctionsthathavetrafficlightsRoughlyth esamesizeassignalledintersectionswiththesamecapacityroundaboutsalsoaresignifi

cantlysmallerindiameterthanmosttrafficcirclesseparateincomingandoutgoingtraff icwithpedestrianislandstoencourageslowerandsaferspeeds

18. Read the text and make up a brief plan:

ROUNDABOUTS

A roundabout is a type of circular junction in which road traffic must travel in one direction around a central island. Signs usually direct traffic entering the circle to slow down and give the right of way to drivers already in the circle. These junctions are sometimes called modern roundabouts in order to emphasize the distinction from older circular junction types. Older designs, called traffic circles or rotaries, are typically larger, operate at higher speeds, and often give priority to entering traffic.

In countries where people drive on the right, the traffic flow around the central island of a roundabout is anticlockwise (counterclockwise). In countries where people drive on the left, the traffic flow is clockwise.

Statistically, roundabouts are safer for drivers and pedestrians than both traffic circles and traditional intersections. Because low speeds are required for traffic entering roundabouts they are not designed for high-speed motorways (expressways). When such roads are redesigned to take advantage of roundabout principles, steps are taken to reduce the speed of traffic, such as curving the approaches.

Modern roundabouts are particularly common in Australia, People’s Republic of China, Malaysia, Iceland, Denmark, France, Hungary, Ireland, Morocco, New Zealand, Qatar, the United Arab Emirates and the United Kingdom. Half of the world's roundabouts are in France (over 30,000 as of 2008). The first modern roundabout in the United States was constructed in Summerlin, Nevada in 1990, and roundabouts have since become increasingly common in North America.

Starting in the 1960s, research in the United Kingdom found that circular junctions with certain geometric characteristics and traffic control schemes tended to be safer than those without them and the engineers building them distinguished them with the term roundabout.

In US technical usage, circular junctions that have the following characteristics are roundabouts and those that do not are considered traffic circles:

Roundabouts require entering drivers to give way to all traffic within the roundabout, regardless of lane position, while traffic circles typically allow traffic to enter alongside traffic circulating in an inner lane without consequence.

Deflection on entry is used to maintain low speed operation in roundabouts. Drivers must manoeuvre (are deflected) around the splitter islands and the central island, at speeds of 15–25 miles per hour (24–40 km/h). Many older traffic circle junctions allow entry at higher speeds due to the lack of deflection,

or require a stop and a 90-degree turn to enter, creating a large difference in speed between entering and circulating traffic which can make it difficult for entering drivers to find suitable gaps in heavy traffic.

Pedestrians are usually prohibited from the central island of roundabouts, and the crosswalk for pedestrians and some cyclists is withdrawn from the junction by at least the length of one vehicle.

Modern multi-lane roundabouts are typically less than 250 feet (75 meters) in diameter, although signalized roundabouts and roundabout interchanges may be considerably larger.

Roundabouts are safer than both traffic circles and traditional junctions— having 40% fewer vehicle collisions, 80% fewer injuries and 90% fewer serious injuries and fatalities (according to a study of a sampling of roundabouts in the United States, when compared with the junctions they replaced). Roundabouts also reduce points of conflict between pedestrians and motor vehicles and are therefore considered to be safer for them. However, roundabouts, especially larger ones with faster traffic, are unpopular with some cyclists. This problem is sometimes addressed at larger roundabouts by taking foot and bicycle traffic through a series of underpasses or alternate routes.

At traditional junctions with stop signs or traffic lights, the most serious accidents are right-angle, left-turn, or head-on collisions that can be severe because vehicles may be moving fast and collide at high angles of impact. Roundabouts virtually eliminate those types of crashes because vehicles all travel in the same direction and most crashes are glancing blows at low angles of impact.

The capacity of a roundabout varies based on the number of entry and circulating lanes, and also on more subtle geometry elements including entry angle and lane width. Also, like other types of junctions, the operational performance of a roundabout depends heavily on the flow volumes from various approaches. A single-lane roundabout can be expected to handle approximately 20,000 to 26,000 vehicles per day, while a two-lane roundabout can be expected to handle 40,000 to 50,000 vehicles per day.

Under many traffic conditions, an unsignalised roundabout can operate with less delay to users than traffic signal control or all-way stop control. Unlike all-way stop intersections, a roundabout does not require a complete stop by all entering vehicles, which reduces both individual delay and delays resulting from vehicle queues. A roundabout can also operate much more efficiently than a signalised junction because drivers are able to proceed when traffic is clear without the delay incurred while waiting for the traffic signal to change.

Roundabouts can also reduce delays for pedestrians when compared to traffic signals, because pedestrians are able to cross during any safe gap rather than waiting for the traffic signal to provide the right-of-way to the pedestrian. During peak hours of congestion when large gaps are infrequent, the very slow

speed of traffic entering and leaving the roundabout can compensate for the smaller gaps and facilitate pedestrian crossings.

Large roundabouts such as those used at motorway junctions typically have two to six lanes around the central hub, and may have traffic lights regulating flow.

Some roundabouts have a divider between traffic turning from one road onto an adjacent one, and traffic within the roundabout, enabling those making such turns to bypass the roundabout entirely. Another type of roundabout is the through-about roundabout or “hamburger” junction. This type of roundabout enables straight-through traffic on one road to cross over the central island, while all other traffic must drive around the island. As a consequence this junction must always be controlled by traffic lights.

The term “gyratory” (for example, Hanger Lane gyratory) is sometimes used in the United Kingdom when a roundabout is large and has non-standard lane markings or priorities, or when there are buildings on the central island; in fact, they are more like traffic circles.

Mini-roundabouts exist at smaller junctions to avoid the use of signals, stop signs or the necessity to give way in favour of one road of traffic. Miniroundabouts can be a painted circle or a low dome. Painted roundabouts and low domes can easily be driven over by most vehicles, which many motorists will do when there is no other traffic, but the practice is dangerous if other cars are present. Mini-roundabouts work in the same way as larger roundabouts in terms of right of way. Mini-roundabouts are sometimes grouped in pairs (a double mini-roundabout) or in “chains”, making navigation of otherwise awkward junctions easier. In some countries there are different road signs used to distinguish mini roundabouts from larger ones. Mini-roundabouts are common in the UK and Ireland, as well as Irapuato in Mexico and Mount Royal and Rosedale in Calgary, Canada.

A slightly larger version of a mini-roundabout, sometimes called a “small roundabout”, is designed with a raised centre surrounded by a sloped “overrun area” of a different colour from the roadway and up to a metre wide called a “truck apron” or a “mountable apron”. The truck apron’s design discourages small vehicles from taking a shortcut over it while at the same time allowing the mini-roundabout to more easily accommodate the turning radius of larger vehicles (such as a truck which may have to navigate the roundabout). These are not well suited for bus routes, as mounting the apron can be somewhat uncomfortable to passengers.

Raindrop roundabouts do not form a complete circle and are in a ‘raindrop” shape. They are appearing at U.S. Interstate interchanges to provide a free-flowing left turn to the on-ramps and eliminating the need for turn signals and lanes. Since the entry and exit slip roads are one-way, a complete circle is unnecessary. This means that drivers entering the roundabout from the bridge do