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 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. BSTs of this type are described by a wide variety of regional terms including chip seal, tar and chip and seal coat.
Other types of BSTs include micropaving, slurry seals and Novachip. These are laid down using specialized and proprietary equipment. They are most often used in urban areas where the roughness and loose stone associated with chip seals is considered undesirable.
Other Paving Methods
Cobbles
Pavers, generally in the form of pre-cast concrete blocks, are often used for aesthetic purposes, or sometimes at port facilities that see long-duration pavement loading. Pavers are rarely used in areas that see high-speed vehicle traffic.
Brick, cobblestone and wood plank pavements were once common in urban areas throughout the world, but due to their high manual labor requirements they are in some countries typically only maintained for historical reasons, while in other countries they are still common in local streets. They make maintenance of cabling and pipelines under the pavement easier but are also harder to walk on.
Likewise, macadam and tarmac pavements can still sometimes be found buried underneath asphalt concrete or Portland cement concrete pavements, but are rarely constructed anymore.
As pavement systems primarily fail due to fatigue (in a manner similar to metals), the damage done to pavement increases exponentially with the axle load of the vehicles traveling on it. Civil engineers consider truck axle load, current and projected truck traffic volume, supporting soil properties and sub-grade drainage in design. Passenger cars are considered to have no practical effect on a pavements service life.
Several pavement design methods have been developed to determine the thickness and composition of pavement required to carry predicted traffic loads for a given period of time. Pavement design methods are continuously evolving.
According to some road tests, heavily loaded trucks can do more than 10,000 times the damage done by a normal passenger car. Tax rates for trucks are higher than those for cars in most countries for this reason, though are not levied in proportion to the damage done.
Unit 18 Traffic Sign
Most countries post signage, known as traffic signs or road signs, at the side of roads to impart information to road users. Since language differences can create barriers to understanding, international signs using symbols in place of words have been developed in Europe and adopted in most countries and areas of the world. The Vienna Convention on Road Signs and Signals of November 8, 1968 defines eight categories of signs:
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A. Danger warning signs
B. Priority signs
C. Prohibitory or restrictive signs
D. Mandatory signs
E. Special regulation signs
F. Information, facilities, or service signs
G. Direction, position, or indication signs
H. Additional panels
However, countries and areas categorise road signs in different ways.
History
Roman milestone
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.
Traffic signs became more important with the development of automobiles. The basic patterns of most traffic signs were set at the 1908 International Road Congress in Rome. Since then there have been considerable change. Today they are almost all metal rather than wood and are coated with retroreflective sheetings of various types for nighttime and low-light visibility.
New generations of traffic signs based on big electronic displays can also change its symbols and also provide intelligent behavior by means of sensors or by remote control. In this sense, road beacons (RBS) based in the use of RFID special transponders buried in the asphalt arise as an innovative evolution for on-board signalling.
Yet another "medium" for transferring information ordinarily associated with visible signs is RIAS (Remote Infrared Audible Signage), e.g. Talking Signs for print-handicapped (including blind/low-vision/illiterate) people. These are infra-red transmitters serving the same purpose as the usual graphic signs when received by an appropriate device such as a hand-held receiver or one built into a cell phone.
Europe
In 1968, the European countries signed the Vienna Convention on Road Traffic treaty, the aim of which was to standardize traffic regulations in participating countries in order to facilitate international road traffic and to increase road safety. Part of the treaty was the Vienna Convention on Road Signs and Signals, which defined the traffic signs and signals. As a result, in Western Europe the traffic signs are well standardized nowadays, although there are still some country-specific exceptions in many countries, mostly dating from the pre-1968 era. The convention has been adapted to allow variations when countries werent expected to follow the main standard.
The basic principle of the European traffic sign standard is that usage of certain shapes and colours are to be used systematically for indicating the same purposes. Triangular shapes (white or yellow background) are used in warning signs. Additionally, the Vienna convention allows an alternative shape for warning signs, a diamond shape, which is rarely used in Europe. The prohibition signs in Europe are round with a red border. Informative and various other secondary signs are of rectangular shape. With the animal warning signs, one can notice national flavour quite often, with symbols of moose, frog, deer, cow, etc., even Polar bear in Svalbard and monkey in Gibraltar, and the Convention allows any animal to be used.
Directional signs have not been harmonised under the Convention, at least not on ordinary roads. As a result, there are substantial differences in directional signage throughout Europe. Differences apply in typeface, type of arrows and, most notably, colour scheme. The convention however specifies a difference between motorways and ordinary roads, and that motorways use white-on-green (e.g. Italy, Switzerland, Denmark, Sweden, Finland, Slovenia, Croatia, Czech Republic, Slovakia) or white-on-blue (e.g. Germany, the Republic of Ireland, France, United Kingdom, Spain, Netherlands, Belgium, Austria, Luxembourg, Poland, Portugal).
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Differences are greater for non-motorways: white-on-blue in Italy, Switzerland, Sweden, Slovakia, Finland and Netherlands (in this case the same as motorways), white-on-green in France, United Kingdom, Poland and Portugal, black-on-yellow in Germany, Luxembourg, Norway, Slovenia and Croatia, red-on-white in Denmark (though white-on-blue on motorway exits), and black-on-white in Spain. Other nations split among the non-motorways.
Secondary roads are different from primary roads in France, United Kingdom, Finland, Republic of Ireland, Switzerland and Portugal, always signposted in black-on-white. In Italy and Sweden, black-on-white indicates only urban roads or urban destinations.
Signposting road numbers differs greatly as well. Only the European route number, if signposted, will always be placed in white letters on a green rectangle.
The languages to be used are according to the convention the language(s) of the individual country. Some signs like STOP, ZONE etc. are recommended to be in English, but the local language is also permitted. If the language uses non-Latin characters, the names of cities and places should also be in Latin transcription.
European countries use the metric system on road signs (distances in kilometres or metres, heights/widths in metres) with the notable exception of the UK, where distances are still indicated in miles. For countries driving on the left, the convention stipulates that the traffic signs should be mirror images of those used in countries driving on the right. This practice, however, is not systematically followed in the two European countries driving on the left, the Republic of Ireland and the United Kingdom. The convention permits the usage of two background colours for danger and prohibitory signs, white or yellow. Most countries use white with a few exceptions like Sweden, Finland, Iceland and Poland, for instance, where the yellow colour was chosen.
Vocabulary
A
abandon , ; (-., -.); ,
Achaemenid [əkémmənid] ancient Persian ruler: a member of a dynasty that ruled in ancient Persia from 553-331 BC
access control
adept , ,
agger , , ,
alignment , , .
alpaca , ;
amount to , , ,
arterial road ,
ascend , ( , );
ascent ,
ash ,
autobahn , ,
axle , ,
B
backpacker
Bactrian ,
binder (), ,
bitumen ;
blight ; ,
blur , ; ; ;
boardwalk ;
bollard
booth ; ; ;
bump ,
bypass ,
camber ; ; , , ( )
car , ,
carriageway
cart ; ;
cartouche , , , , ( )
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causeway , ( ); ( )
central reservation
chariot
clog ; ; (); (); ()
coach , ( ),
cobblestone , ;
coerce , , ,
cohesion ; ,
conch ,
congestion ( )
contour , ;
controversy , , , ,
conventional , ,
converge ( , . .); (on);
convex ,
cord , , (, ), , ,
corduroy , ,
corral , ( )
courier , , ,
crash barrier ,
craze ,
culvert
curb ; ()
D
deleterious , ,
demonstrably , , ,
designation , ,
deteriorate ; ; , ,
disrepair ; ,
ditch , , , , ,
diverge (from), ; ; (to)
domestication
drain , ; , ; ; , , ;
driveway , ,
dromedary
dyke , , , , ,
E
easement rights - - ( , , ..)
emulsion
equestrian ;
even , ( ),
F
facilitate ; ;
fatigue ()
ferry ,
flank ,
flea market ,
flyover
flyover crossing
foam , ; ; ;
footpath ,
fossa , ,
franchise , - ,
freeway , ,
frontage - , , ..; ( , )
G
gauge ..
garrison , ( , ..)
genteel ;
gig ; ( , )
gilded
gorge , , ,
grade separation ;
gradient ,
graze , ()
grid ,
grout
guardrail ,
gully ; ( ); ,
gutter , ; ;
gyratory
H
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hairpin ( 180 )
heel
herringbone ,
heyday , ,
honeycomb () ; ,
hydroplaning ,
I
impetus ; , , (to - -. )
Indus .
interchange ()
interchange point ()
intermittent ; ;
itinerary , , ,
intrinsic , , , ,
J
jerky
junk ,
junction ,
L
lane
largesse ,
lima bean ,
lime
livestock
log ;
lure ; , ,
M
macadam ,
macadamize
mandatory ,
maritime
marsh ,
mattock ;
median ,
median strip
mitigation , (, ); (, )
mortar ; ,
motorway ,
movable bridge
N
navel , , , (-.)
nomad
Norse , ;
notch , -., , ; , ,
O
oak
occupancy ; ; ;
odd ,
off-ramp
offshoot , ,
on-ramp
overpass ; ; ,
P
pace ;
parcel
parish (, )
pastoral ,
pavement . , . , ,
paver , , , ( );
peat
pier , , , ; , , ,
piling ,
plait (); , , , ,
plaited rope
plough , , ;
plunge , , ( )
ply , , , (), , , ( . .)
Portland cement -
prerequisite
pylon , ; ,
Q
quarry , ,
quicklime
Quipu (noun) A contrivance employed by the ancient Peruvians, Mexicans, etc., as a substitute for writing and figures, consisting of a main cord, from which hung at certain distances smaller cords of various colors, each having a special meaning, as silver, gold, corn, soldiers. etc. Single, double, and triple knots were tied in the smaller cords, representing definite numbers. It was chiefly used for arithmetical purposes, and to register important facts and events.
R
radius radii
ramp (. ),
rebar ; ; ( )
reinforce ;
rejuvenate , ,
relay , (), ,
relegate , (to - -.); , ;
reservation , ; ,
retrofit , , ,
retroreflector ,
reversible lane
ridge , ,
rig ; ; ( );
right-of-way / ,
rill ; , ,
ring road ,
roadbed
rod , , , , , ( 5 c )
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roller , ; ;
roundabout ,
tresspass , , ,
rubble , ,
rumble strip ( )
rut
S
sag , ;
sedentary ; ,
segregation , ; ,
shock .
shoulder , ()
shunpiking
sidewalk ,
skid-resistance
slab ; ,
slick ;
slip road , ( )
slope ; ; ;
slurry , ; ,
spade
spring ,
stagnant ( ); , , ,
statutory instrument ,
steep grade ,
steer , ;
strand -., , , . ., , ;
subgrade . , ; ( ),
suffice , ; (for)
suspension , , ;
swath , ,
sway (), ()
T
tailgate (), ,
tamp , , ;
tar ; ;
tarmac ,
tensile ;
thoroughfare (),
toll , ,
trackway ,
trail ,
transit , ; , ; ()
transverse profile
traverse , ,
treacherous ;
tread , ; ,
trekking (, ) , ()
trespass ( , , ); ()
trumpet ,
tyre ( , (, ..)), ;
U
underpass , ; ;
V
verge , ,
vessel , , ( )
viaduct ;
villa , , ( ), .-.
viscous , , ; ,
void ; ; ; ( ); 3) ( )
W
wayfarer ,
wheelchair -
weigh anchor
wetland
wheelright
woven , , ,
Y
yield ,
