Abu Dhabi, United Arab Emirates. STANDARD CONSTRUCTION SPECIFICATIONS (PART 1 - ROADS, Second Edition 2020)

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Table 9-3 : Jacket thickness

Calculated diameter of

cable under jacket (mm)

Jacket (mm)

Multiple Conductor Cables:

10.8 or less

1.14

10.8

– 18.1

1.52

18.1

– 26.7

2.03

Conductor size (AWG)

Jacket (mm)

Flat Twin cable:

– 12

1.14

– 6

1.52

Table 9-4 : Insulator thickness

Conductor Size,

AWG

Polyethylene (mm)

Polyethylene plus nylon

Polyethylene (mm)

Nylon (mm)

0.635

4.064

0.102

0.635

4.064

0.102

0.762

4.064

0.102

0.762

4.064

0.102

0.762

4.064

0.102

3. Polyethylene insulation with polyethylene or polyvinylchloride jacket. Polyethylene insulation

compound  shall conform to  ASTM  D1248  Type 1,  Class  B,  Grade  4.   Polyethylene jacket
compound shall conform to ASTM D1248, Type 1, Class C, Grade 5.  Polyvinylchloride jacket
compound  shall  meet  the  following  requirements  when  tested  in  accordance  with  ASTM
D1047.  This insulation shall have the following properties:

1. Initial properties:

i. Tensile strength - 1.055 kg/mm

., minimum.

ii. Elongation at rupture - 100 %, minimum.

2. After 5 days in air oven at 100

i. Tensile strength - 85 % of original, minimum.

ii. Elongation at rupture - 60 % of original, minimum.

4. Polyethylene insulation, extruded nylon covered with neoprene jacket. Polyethylene

insulation compound shall conform to ASTM D1248 Type 1, Grade 4, Class A or B. A
covering of clean nylon shall be extruded directly over the polyethylene insulation. Nylon shall
meet the requirements of ASTM D372 Type I. Neoprene jacket compound shall conform to
the requirements of Insulated Power Cables Engineer's Association (IPCEA) Specifications
"Neoprene Heavy Duty Black", and, in addition, shall have a tear strength of 0.021 kg/mm2
minimum.

5. Shielding. If shielded electric cable is specified, the conductors shall be stranded tinned-

copper twisted approximately 50 turns per m. Insulation shall be of the polyethylene, 0.094
mm nominal thickness for AWG No. 12 cable and 0.81 mm nominal thickness for AWG No.

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14 cable.  Shielding shall be of aluminized mylar or polyester.  One AWG No. 16 stranded
tinned-copper drain wire shall be provided.  Shielding shall be 100 % effective by providing
a metal to metal contact between adjacent wraps.  Jacket shall be of chrome vinyl, 0.94 mm
nominal thickness for AWG No. 12 cable and 0.81 mm nominal thickness for AWG No. 14
cable.  Another nylon sheath of 0.08 mm nominal thickness shall be applied over the vinyl
jacket.

6. Capacitance measured between conductors shall be 25 micro-microfarads or less per 300

mm. Capacitance measured between the conductors with one conductor connected to the
shield shall be 50 micro-microfarads or less per 300 mm.

7. Colour coding. Each insulated conductor shall be colour coded in accordance with the
8. Table 9-5, or as directed by the Engineer.

Table 9-5 : Insulated conductor colour code

Conductor number

Base colour

Tracer

Black

White

Red

Green

Orange

Blue

White

Black

Red

Black

Green

Black

Orange

Black

Blue

Black

White

All electrical cable colour code shall be consistent throughout the system.

9. Fillers. Fillers, when used, shall be of a non-metallic moisture-resistant material, as directed

by the Engineer.

10. Tape. Conductor assembly shall be covered with a spiral wrapping of a moisture-resistant

tape applied so as to lap at least 12.5 % of its width.

11. Construction. Cables shall be of the twisted type of construction, except that 2-conductor

cable may have the conductors laid parallel to one another.  Conductors shall be individually
insulated.  Twisted conductors shall be laid up concentrically, and fillers shall be used, where
necessary, to form a firm and uniformly rounded core.  Each layer shall have a spiral lay in
the direction opposite to that of adjacent layers.   Cross section of the cable shall have all
layers of conductors in concentric circles.  Each conductor in each layer shall  maintain its
position relative to every other conductor in the layer throughout the entire length of cable.
Formed cable shall be firmly bound together by a helically applied layer of tape, except when
rubber compound is used for filling the interstices, the tape over the core may be omitted.
Electrical cables connecting the controller to each signal lamp shall have spare capacity of
at least two conductors.

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12. Identification. Each shipping length of cable shall have a tape showing the name of the

manufacturer and the year in which the cable is manufactured, placed over or under the tape
covering  the  conductor  assembly  before  application  of  outer  coverings.    As  an  alternate
method  of  identification, the  above  information may  be  applied  to  the  outer  surface  of the
sheath.    Sheath  shall  be  marked  at  10  m  increments  in  ascending  numerical  order  for
measurement and payment purposes.  Electric cables furnished shall not be dated more than
5 years prior to the time of installation.

13. Communications cable for interconnection, computer control, and audio transmission

(telephone) shall be multipairs cable(s) with colour-coded twisted pairs and No. 19 AWG solid
copper conductors. All colour coding for communications cable shall be consistent throughout
the system.

14. Communications cable used in this Project shall be similar to the cable used in the existing

system, i.e., conventional-type electric cable described above.

15. Installation. Cables shall be installed in number and sequence as approved by the Engineer.

9.5.2.6

Poles and Mast Arms

Vehicular and pedestrian signal poles and mast arms shall be designed to support the traffic signal
loading as required by the Engineer, specified herein or shown on the Contract plans. Design and
fabrication shall conform to the requirements of AASHTO LTS-5-12. Components of traffic signal
poles and mast arms shall meet the requirements specified herein.

Vehicular and pedestrian signal poles and mast arms shall be of durable, visually acceptable design
and visually compatible with the existing signal poles. Poles shall be installed on concrete
foundations all as approved by th

e Engineer. Poles shall not have "breakaway-on-impact" feature.

Clearance between top of pavement and bottom of lowest vehicular signal head mounted on mast
arms shall be no less than 6.20 m and no greater than 6.40 m, taking vertical wind deflection into
account, unless otherwise directed by the Engineer.

Generally, vehicular and pedestrian signal heads shall be installed on traffic signal poles.  However,
in  certain  instances  pedestrian  signals  may  be  installed  on  street  light  poles  when  shown  on  the
Contract  plans  or  as  directed  by  the  Engineer.   In  such  instances the  street  light  pole  used  shall
comply with the material, construction and quality described in these Standard Specifications.

Poles and mast arms shall be made of galvanized steel and as approved by the Engineer with a
minimum outside diameter of 114 mm. Poles shall be welded to the baseplate as shown on Contract
plans. Baseplate of traffic signal poles shall be ASTM A36

structural steel. Shape and dimensions

of the baseplate shall be as shown on the Contract plans.

Ground rods, if not supplied by others with the pole foundations, shall be 19 mm in nominal diameter
and 2.5 m long. A ground clamp capable of accommodating a No. 6 bare copper wire shall be
furnished with the rod.

All vehicular signal poles shall be equipped with a fuse of adequate capacity at the base.

All  traffic  signal  poles  shall  have  an  identification  tag  that  is  fabricated  from  stainless  steel  or  a
suitable  non-ferrous  material  as  directed  by  the  Engineer.  The  identification  tag  shall  identify  the
manufacturer, and the date of manufacture.

9.5.2.7

Pole and Mast Arm Assembly

Steel mast arm assembly and pole shall meet the following requirements:

1. Steel mast arm assembly and pole shall consist of a mast arm assembly, a pole and a base,

and other appurtenances. Configuration of the mast arm assembly, pole and base shall be
in accordance with the details shown on the Contract plans.

2. Steel mast arm assembly and pole shall be designed to support one 36.3 kg signal with a

projected area of 1.366 m

at the free end of the mast arm, one 22.7 kg signal with a projected

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area of 0.81 m

mounted 3.7 m inward on the mast arm, and one 56.7 kg signal with a

projected area of 0.70 m

mounted on the mast arm near the shaft, or the signal loading

shown on the Contract plans, whichever is greater, based on a 120 km per hour wind velocity
plus 30 % gust factor.

3. Design and fabrication of the mast arm assembly, pole, and base shall conform to the

requirements of AASHTO LTS-5-12. No other design criteria are acceptable. Mast arm and
pole shall be fabricated from steel of structural quality with specific ASTM designations,
having minimum yield strength of 26.7 kg/mm

., either of steel tubing or from welded sheets

and plates. Base and flange plates, shall be of structural steel conforming to ASTM A36 or
better or of cast steel conforming to ASTM A27, Grade 70-36 or better.

4. Mast arm and pole must be of single length design i.e. not of sectional design. A handhole

with reinforced frame shall be provided on each pole near the base.  Handhole cover shall
be fastened with stainless steel screws.  All mast arm assemblies, poles, and bases, except
those  fabricated  from  material  conforming  to  ASTM  A606,  Type  4,  shall  be  galvanized  in
accordance with AASHTO M 111.

5. Mast arm assembly shall be attached to the pole in an angle from the horizontal of 5

unless

otherwise  directed  by  the  Engineer  and  shall  provide  the  minimum  clearances  specified
herein.  Mast arm connection to the pole shall be as shown on the Contract plans and shall
be  designed  to  fail  in  rotation  upon  impact  while  being  able  to  withstand  the  specified
loadings.

6. When fully loaded with signal heads as specified herein or as directed by the Engineer,

maximum deflection at the free end of the mast arm shall not be more than 50 mm.

9.5.2.8

Vehicular Signal Heads

Vehicular  signal  heads  shall  be  mounted  on  mast  arms  to  increase  visibility,  and  supported  by
pedestal mounted signal heads as shown in the Contract plans, as directed by the Engineer.  Span
wire  mounting  shall  not  be  used.  Although  incandescent  type  signal  heads  are  shown  in  this
specification, only LED type signal heads shall be used in the Emirate of Abu Dhabi.

Vehicular signal heads shall be comprised of up to four signal faces together with necessary
mounting devices capable of holding signal heads rigidly in place against wind and other external
effects. Vehicular signal heads with four signal faces are not currently in use within the Emirate of
Abu Dhabi. The installation of vehicular signal heads with four signal faces shall be as directed by
the Engineer.

Vehicular signal faces shall be comprised of three sections as shown on the plans, specified herein
or as directed by the Engineer.

Vehicular signal sections shall be placed vertically one on top of the other with Green indication at
the bottom, Amber indication at the middle, and Red indication at the top. Arrow indications, if any,
shall be placed immediately below the signal indication of the same colour.

All elements of the vehicular signal heads shall be properly grounded as specified herein and as
directed by the Engineer.

a. Conventional Vehicular Signal Heads

Signal faces shall be modular and comprised of individual signal sections. Components of each
signal section shall comply with the following requirements.

1. Housing and door shall be one of the following:

Cast aluminium housing and door shall meet the alloy and tensile requirements
conforming to ASTM B85 or B108.

Door shall be attached to the housing with two

stainless steel hinge pins, and shall be held closed with a stainless steel latching
device. All access openings shall be provided with neoprene or rubber gaskets to
make the housings waterproof and dustproof.

ii.

Polycarbonate housing shall be moulded in one piece and shall be capable of
withstanding 31.8 kilograms of impact without fracture or permanent deformation.
Polycarbonate resin shall be minimum 2.3 mm thick.

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iii.

Door shall be attached to the housing with two stainless steel hinge pins, and shall
be held closed with a stainless steel latching device.   All access openings shall be
provided  with  neoprene  or  rubber  gaskets  to  make  the  housing  waterproof  and
dustproof.    Ends  of  each  signal  face  adjacent  to  the  mounting  hardware  shall  be
reinforced  with  metal  plates  of  adequate  thickness  to  keep  the  signal  face  from
vibrating in the wind.

2. Optical Unit: Conventional signal section shall have an optical unit conforming to the

requirements of the latest ITE

Vehicle Traffic Control Signal Heads Standard

and the

following requirements:

Signal Lamp:  Signal lamp shall be a nominal 100 watts luminaire suitable for use in
traffic  signal  heads,  capable  of  operating  at  240  volts,  and  shall  have  an  average
rated life of not less than 6,000 hours.  Lamp socket shall be heat-resistant, rotatable
and have a lamp grip to prevent the lamp from working loose by vibration.

ii.

Reflector: Reflector shall be of parabolic silvered glass, metalized plastic or Alzak
aluminium and shall conform to the Institute of Transportation Engineers Standards
(ITE Publication No. ST-017).

iii.

Signal Lens: All vehicular signal lenses shall be antiphantom and 300 mm in

diameter unless otherwise directed by the Engineer and shall conform to the Institute
of Transportation Engineers Standards (ITE Publication No. ST-017). The
components and circuit boards shall not be visible through the lens.

iv.

Signal Dimmers: When specified by the Contract plans or Particular Specifications,
signal dimmers shall be provided for the amber signal sections. Dimmer shall allow
the signal lamp to operate at full intensity under daylight conditions and to reduce
proportionally to 25



5 % to full intensity at night. A dimmer shall not control more

than one amber section for each direction.

3. Terminal Block: Each signal face shall contain a terminal block with at least 12 terminals.
4. Visor: The conventional signal section shall be furnished with a cut-away type visor over

each aspect. The visor shall not be less than 1.3 mm in thickness. The visor for a 305 cm
signal section shall be a minimum of 229 mm in length.

5. Mounting bracket: Mounting bracket shall be made of aluminium. Signal heads with more

than one signal face shall be furnished with terminal compartments. Each terminal
compartment shall contain a terminal block with at least 16 terminals.

6. Colour. Aluminium housing and bracket shall be painted with one coat of primer and finished

with  two  coats  of  Federal  Yellow  (as  specified  by  U.S.  Federal  Highway  Administration)
enamel,  dark  olive  green  enamel  or  as  specified  by  the  Engineer  in  consultation  with  the
Owner.  Aluminium signal door and visor shall be shop painted with one coat of primer and
finished  with  two  coats  of  dull  black  paint.    For  polycarbonate  signal  heads,  the  above
specified colours shall be an integral part of the material composition.

b. LED Vehicular Signal Heads

Contractor shall furnish and install LED vehicular signal heads in accordance with all the
requirements as per Article 9.5.2.8, as shown in the Contract plans and as approved by the Engineer,
in addition to the following requirements:

1. Contractor shall submit to the Engineer at least 3 different types of traffic signal heads that

shall be considered for installation in this project, similar to other traffic signal heads in the
vicinity of the Project area, and in accordance with any existing Owner guidelines and
regulations.

2. Engineer shall review the proposed materials and recommend the most suitable one to the

Owner. Contractor shall not procure, deploy, or install any traffic signal head without obtaining
the Engineer’s approval in advance.

3. LED signal module shall be capable of replacing the existing optical components or signal

module in a signal housing, or shall provide a complete replacement of the signal head.

4. LED signal module lens may be a replaceable part, without the need to replace the complete

LED signal module.

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5. Assembly and manufacturing processes for a module shall be designed to ensure all internal

LED and electronic components are adequately supported to withstand mechanical shock
and vibration due to high winds or other local climatic conditions.

6. LED traffic signal heads shall comply with the applicable requirements of BS EN 12368.

c. Traffic Signal Backplate

Traffic  signal  backplate,  if  and  when  specified,  shall  be  made  of  sheet  aluminium  or  sheet  ABS
plastic.  Sheet aluminium shall have a nominal thickness of 1.587 mm and shall conform to ASTM
B209 Alloy 3003 H 14.  Sheet ABS plastic shall have a nominal thickness of 3.968 mm and shall
have a minimum tensile strength of 29.65 N/mm

Backplate shall be designed to be attached to a signal face without interfering with the opening and
closing of the traffic signal door.  It shall be rectangular in shape with ground corners and shall be of
such dimensions as to give an exposed margin of 127  mm on each side.  Backplate shall not be
composed  of  more  than  four  pieces,  and  a  minimum  of three  evenly spaced  stainless  steel  bolts
meeting the applicable requirements of ASTM A193, Class 1, Grade 8, shall be used to connect any
two pieces.

Back plate screws and nuts shall be self lockable and resistant to vibration.

Traffic signal backplates are not applicable for decorative signal heads, as directed by the Engineer
and approved by the Owner.

d. Traffic Signal Backplate Finishing

Aluminium backplates shall be painted with one coat of primer and finished with one coat of dull
black paint. For plastic backplates, the black colour shall be an integral part of the material
composition.

9.5.2.9

Pedestrian Signal Heads

Pedestrian signal head and faces shall be mounted as specified herein. Pedestrian signal heads
shall have no more than two faces and shall be mounted in a vertical position. Use of span wire
mounting will not be permitted.

Pedestrian signal heads and faces shall be mounted in one of the following ways as shown on the
Contract plans and as approved by the Engineer:

1.  On the vertical portion of the traffic signal poles.
2.  On the top of poles as specified.
3.  Installed  within  the  sidewalk  poles  to  be  furnished  and  installed  separately  under  this

Contract.

Pedestrian signals shall allow pedestrians to cross the roadway within the pedestrian crosswalks
during the same phases with through and right turning vehicles in the same direction, as shown on
the Contract plans.

Pedestrian signals shall be mounted on the signal poles and top of post in an approved manner and
so that the bottom of the signal head is no less than 2.4 m and no more than 3.0 m above the top of
the curb. Pedestrian signals shall not be mounted out over the traffic lanes. In general, the
pedestrian signals shall be no closer than 1.0 m from the edge of pavement unless otherwise shown
on the Contract plans or approved by the Engineer.

The Engineer’s representative shall confirm the

exact location of all pedestrian traffic signal system equipment on site with the Contractor prior to
installation.

a. Conventional Pedestrian Signal Heads and Mounting Accessories

Pedestrian signal faces shall be of a sectional design, completely compatible with signal head
hardware and when mounted in any standard arrangement (i.e. other than with pole) the appearance
of the pedestrian signal head will be compatible with the balance of the traffic signals.

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All pedestrian signal poles shall be equipped with a fuse of adequate capacity at the base.

1. Poles for the top-mounted pedestrian signal heads shall conform to the following:

Pedestrian  signal  pole  shall  consist  of  a  nominal  100  mm  diameter  steel  pole  and a
base, together with anchor bolts and other appurtenances.  Configuration of the pole
and base shall be in accordance with the details shown on the Contract plans and shall
be subject to approval by the Engineer.  Foundations for the poles shall be included
and constructed under the respective civil works contract.

ii.

Steel pole shall be designed to support two pedestrian signal heads and withstand
steady wind velocity of 120 km/hr. with a gust factor of 30 % plus taking into account
the requirement imposed by the exposed surface area and total weight of signal heads
and brackets.

iii.

Design and fabrication of the pole and base shall conform to the requirements of
AASHTO LTS-5-12. Pole shall be fabricated from steel of structural quality with
specified ASTM designations, having a minimum yield strength of 331 N/mm

., either

of steel tubing or from welded sheets and plates. Base and flange plates shall be of
structural steel conforming to ASTM A36 or of cast steel conforming to ASTM A27,
Grade 70-36.

iv.

Pole  must  be  of  single  length  design  i.e.  not  of  sectional  design.    A  handhold  with
reinforced frame shall be provided on each pole near the base.  Handhole cover shall
be fastened with hexagonal head stainless steel screws.  All poles and bases, except
those  fabricated  from  material  conforming  to  ASTM  A606,  shall  be  galvanized  in
accordance with AASHTO M 111.

2. All pedestrian signal heads shall conform to the requirements for materials as specified under

Article 9.5.2.8 and as follows:

Pedestrian signal heads to be mounted on poles shall have one or two signal faces. In
the case of two signal faces, they shall be placed either back to back or at an angle, as
shown on the Contract plans.

ii.

Pedestrian signal heads to be mounted in poles shall have one signal face, or two signal
faces placed at a right angle or back to back.

iii.

The  pedestrian  signal  head  shall  be  of  sectional  design  completely  compatible  with
vehicular signal head mounting assemblies and other hardware.  When mounted on a
pole  or  on  the  vertical  shaft  of  a  signal  pole  with  mast  arm,  the  appearance  of  the
pedestrian  signal  head  shall  be  compatible  with  the  balance  of  the  traffic  signals
furnished as part of the system.

3. Signal face and signal section shall conform to the following:

Section with the DON'T WALK symbol shall be placed directly above the WALK section and
shall be illuminated in red.

ii.

Optical unit of the pedestrian signals shall be same as the vehicular signals except the
lens which shall be square in shape and a nominal 300 mm in size.

4. All elements of the pedestrian signal heads shall be properly grounded as specified herein,

and as approved by the Engineer.

b. Animated LED Pedestrian Signal Heads and Mounting Accessories

This item shall comply with all requirements Sub-article a of Article 9.5.2.9, except for Clause 3 which
is revised to read as follows:

1. Signal face and signal section shall conform to the following:

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Each pedestrian signal face shall have two signal sections each 360 mm x 360 mm
in size and square in shape with the two signal sections placed vertically. One section
shall have a WALK symbol in the shape of a walking person and the other section
shall have a DON'T WALK symbol in the shape of a vertically placed human hand.
Other symbols such as STANDING, WALKING, and Animated person may be
installed as approved by the Engineer. The animated walking person is the preferred
one for this project. Symbols shall be at least 230 mm high. Section with the WALK
symbol shall be placed at the bottom directly below the DON'T WALK section and
shall be illuminated in green. The WALK symbol shall start flashing (fast walking for
the animated person) at the end of the pedestrian green interval. Flashing green may
be substituted by animated green as approved by the Engineer. The section with the
DON'T WALK symbol shall be placed directly above the WALK section and shall be
illuminated in red.

ii.

Optical unit of the pedestrian signals shall be same as the vehicular LED signals
except the lens which shall be square in shape and a nominal 300 mm in size.

2. All elements of the pedestrian signal heads shall be properly grounded as specified herein,

and as directed by the Engineer.

3. Pedestrian Animated LED signal heads shall comply with the applicable requirements of BS

EN 12368.

c. LED Pedestrian Countdown Clock Counter and Mounting Accessories

Contractor shall furnish and install LED pedestrian countdown clock counter (CDC) including
mounting accessories as directed by the Engineer. CDC shall comply with all requirements herein
this specification as applicable and as directed by the Engineer.

Countdown clock counter (CDC) shall be furnished and installed at the rate of one countdown
counter for every approach.

9.5.2.10

Pedestrian Actuation

Subcontractor shall supply and install pedestrian actuation detectors for pedestrian movements at
intersections as shown on the Contract plans, required in the Particular Specifications, and approved
by the Engineer.

a. Pedestrian Pushbutton

Pedestrian pushbutton (complete) shall consist of the installation of a pedestrian pushbutton, a sign
displaying  instructions  for  usage,  arrow  signs  pointing  to  the  crosswalk  it  controls,  all  necessary
cabling and wiring, and the necessary programming of the intersection traffic signal controllers.  In
the case of two (2) or more pushbuttons on a single traffic signal pole, the Contractor shall attach
the pushbuttons on  suitably sized brackets that provide spacing between the pushbutton units as
directed by the Engineer.

Pedestrian movements shall be serviced only when called and shall be either a separate phase or
concurrent with the respective vehicular phase as shown on the Contract plans and as approved by
the Engineer.

Instructions sign shall be in both English and Arabic languages and shall be on 3 mm aluminium
plate with engineering grade reflective sheeting or similar material as directed by the Engineer.
Signs shall be suitably mounted above the pushbutton unit on the pole or pylon using tamper-
resistant clamps or industrial adhesive as approved by the Engineer.

Housing of the pedestrian pushbutton shall be fabricated out of diecast aluminium. Pushbutton unit
shall be extremely sturdy, tamper-resistant, and weatherproof.  It shall be securely attached to the
pole or pylon.  Unit shall be completely sealed and all wiring connections shall be from the back of
the unit through a compression type cable entry gland.  Pushbutton unit shall have an illuminated
indicator panel to show the state of operation i.e. wait/walk of the respective pedestrian signal.

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Programming of the signal operations to accommodate pedestrian pushbuttons shall not disallow
the coordinated operation of the local traffic signal controller, whether it is under arterial progression
control or under the central computer control.

b. Audible Tactile Facility

Contractor shall furnish and install pedestrian push buttons with audible speaker and tactile
indicators as applicable, as shown on the Contract plans and as approved by the Engineer.

Pedestrian push button station shall allow pedestrians both regular and with disabilities including
visually, and hearing impaired people to use the push button to allow them to cross roadways safely.

9.5.2.11

Vehicle Actuation and System Detectors

Subcontractor shall supply and install vehicle actuation detectors for intersection controls and data
collection, and system detectors for the central computer control systems as shown on the Contract
plans, required in the Particular Specifications and approved by the Engineer.

Location of the system detectors shall be in areas of free flow between intersections, are not affected
by recurrent traffic queues, as approved by the Engineer. Basic hardware for both vehicle actuation
detectors and system detectors shall be the same and they shall be interchangeable.

Contractor shall submit to the Owner for field test and evaluation 2 detectors of the same type and
manufacture to be installed under this Contract. Contractor shall also submit a certificate verifying
that the detectors conform to the requirements defined herein and that these same detectors have
been thoroughly field-proven and time-tested as to their reliability and maintenance characteristics.

Each detector shall consist of three elements: the detector amplifier unit, the roadway loop and the
lead-in  to  the  amplifier  unit.    All  units  shall  be  interchangeable  without  any  wiring  or  component
changes.    Field  tuning  shall  not  require  a  meter,  circuit  changes,  substitutions,  modifications,  or
additions  to  the  sensing  unit.    Unit  shall  not  drift  with  time  or  environmental  changes  after  initial
tuning.   Unit  shall  be  housed  in  a  nonferrous,  plug-in  case.    All  component  parts  shall  be readily
accessible with the case removed.  Detector amplifier unit shall be mounted in the local controller
cabinet.

a. Loop Detectors

Subcontractor shall supply and install vehicle actuation loop detectors for use in conjunction with the
installed systems at locations as shown on the Contract plans, where deemed necessary by the
system requirements, as specified herein, as approved by the Engineer

Subcontractor shall specify the quantity and location of loop detectors to allow the traffic control
system to operate fully and satisfactorily in consultation with the Employer.

Subcontractor shall install detectors in roadway pavement by neat saw cutting of the pavement to
the nearest curbstone conduit. Subcontractor shall restore the pavement after detector installation
to the satisfaction of the Engineer. Curbstones, sidewalks, etc. disturbed for detector installation
shall be similarly restored. Maximum depth of loops shall not exceed 200 mm under the lane surface.

Subcontractor shall take extra care at curb side to protect existing loops' cables and avoid cutting
them. Subcontractor shall be responsible to reinstall any existing loop which may be damaged due
the installation of new loops. Subcontractor shall restore the pavement, kerbs, sidewalks, etc., after
detector installation to the satisfaction of the Engineer.

Subcontractor shall extend where necessary all loop lead-in cables to reach the field control cabinet
as required by the traffic signal controller specifications and directed by the Engineer. Subcontractor
shall supply all required cable extensions, joints, connectors, etc.

Subcontractor shall use elastomeric fuel resistant joint sealant to seal pavement cuts after the
installation and accepted testing of the loops.

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1. Technical Requirements

Detector amplifier unit shall be a complete, functional unit and planned so as to operate on 240 volt,
50 hertz, single-phase alternating current. Variations in voltage of



20 % or ambient temperature

changes between -5° C and 90° C shall not affect the normal operation of the unit nor shall false
calls be issued when input voltage fluctuates between the above limits.

Power supply shall be made an integral part of the unit.  Incorporated in the design of the unit shall
be a fail-safe feature which, in the absence of power, places a continuous call on the sensing circuit.
Following power failure the unit shall restore to operation within one second.

A  manual  switch  shall  be  provided  on  the  front  of  the  unit  for  the  selection  of  either  motion  or
presence sensing.  In the "presence" position, the unit shall sense the presence of a vehicle within
the loop up to a minimum of 15 minutes after which it cancels the call.  A minimum of three operating
frequencies shall be provided to avoid crosstalk between adjacent detectors, and a minimum of three
sensitivity ranges shall be provided.

Each detector loop shall be comprised of at least three turns of loop wire. Each loop shall be
individually connected to the lead-in cable. Each loop shall be linked to a different channel in the
traffic signal controller.

Sensor circuits shall be of the microprocessor based type. Unit shall operate when connected to an
inductance of 50 - 1000 micro-henries and shall render reliable detection when a conductive mass
affects a 0.02 % change in inductance and shall be neither position nor attitude sensitive. Unit shall
be capable of operating properly when connected to field loop feeder length up to 152.4 m and total
loop area up to 37.2 m2.

An  indicator  lamp  shall  be  permanently  mounted  to  the  front  of  the  unit  and  shall  indicate  each
actuation.    Necessary  connectors  shall  be  supplied  with  each  unit  for  connection  to  the  external
circuitry.  The manufacturer shall furnish certification that the detector conforms to the requirements
of these specifications.

2. Surge Protection

All loop detector connections to the detector terminal shall be protected from lightning by using 20
volt zener diodes back-to-back across the loop leads or by a device that has been field proven and
approved by the Engineer.

3. Roadway Loop Wire

Loop wire shall be 600 volt single conductor and shall conform to the requirements of IMSA 51-3,
1984 of the Specifications for Signal Cable of the IMSA (International Municipal Signal Association.
Manufacturer's name and the identification of the type of wire shall be plainly marked on the outside
jacket and certification shall be furnished that the wire conforms to the requirements of the
designated specifications.

Conductor shall be insulated, uncoated copper, stranded wire and shall retain its critical properties
with no adverse effects to its functional capabilities while conforming to the requirements of Table
9-6.

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Table 9-6 : Roadway loop wire parameters

Maximum diameter (AWG number)

Maximum resistance at 20° C (ohms/304.8 m)

2.650

Maximum breaking strength (kg)

56.3

Minimum tensile strength (kgs/sq. cm)

2706.6

Loop wire shall be insulated with a chemically cross-lined polyethylene insulation conforming to the
requirements of Table 9-7.

Table 9-7 : Roadway loop wire polyethylene insulation

Maximum thickness (mm)

0.76

Maximum operating temperature (degrees C)

Minimum emergency overload temperature (degrees C)

127

Minimum installation temperature (degrees C)

-23

Minimum elongation (megohms/304.8 m)

350

Minimum insulation resistance (megohm/304.8 m)

5,000

Maximum dielectric constant

Minimum tensile strength (% of original)

Minimum elongation (% of original) after 7 days in an air oven at 120

Maximum mechanical moisture

Absorption (mg/cm

)

Change in specific inductive capacity (% of maximum) after 1 to 14 days in
water at 74

Retention of critical properties

(% of minimum) after 80 days at 120

Minimum breakdown voltage

15,000

4. Lead-In-cable and Sealer

Lead-in-cable shall consist of a twisted pair of number 12 or 14 AWG stranded conductors, insulated
for 600 volts and shielded in conformance with the requirements of IMSA 50-2.  Insulated conductors
making up the cable shall be colour-coded.  Manufacturer's name and the identification of the type
of  cable  shall  be  plainly  marked  on  the  outside  jacket  and  the  manufacturer  shall  furnish  a
certification that the cable conforms to the requirements of these Specifications.

Sealer shall be a suitable epoxy and capable of curing in a maximum time of 4 hours at 10° C. Curing
is defined as capability of withstanding normal traffic loads without degradation.

YSTEM

Lead-in-cable and roadway loop wire shall be securely connected in a suitable loop detector splice
encapsulation kit approved by the Engineer.

5. Field Tests

Prior to applying the loop sealant, the Subcontractor shall perform the following tests. Tests shall
be recorded for each of the detectors.

1.  Megger Test - Resistance to ground not less than 1 megohm.
2.  Inductance Test - Inductance between 50 - 1000 micro-henries at 50 kHz.
3.  Continuity Test - Closed electrical loop.
4.  Circuit Resistance - Resistance shall not exceed 2 ohms.

Each test shall be repeated at the local controller cabinet to include the loop lead-in. No test shall
be considered acceptable unless performed in the presence of and to the satisfaction of the
Engineer.

6. Additional Loops for Traffic Violation Recording Equipment

At  certain  locations,  where  shown  in  the  Contract  plans  or  directed  by  the  Engineer,  the
Subcontractor may be required to provide for the installation of traffic violation recording equipment
in  the  future.  At  such  locations,  it  is  necessary  to  install  the  detection  equipment  in  the  form  of
inductive loop detectors embedded in the pavement, and with the lead-in cable installed up to the
foundation  of  the  traffic  violation  recording  equipment.    Equipment  shall  comply  with  the
requirements of the applicable authority.

Additional loops for traffic violation recording equipment item covers the supply and installation of
the detection equipment as described above for one approach covering two lanes of traffic. Loop
wire and lead-in cable shall fully comply with the specifications in Paragraphs 3 and 4 of Sub-article
a of Article 9.5.2.11.

b. Alternative Detection Technology

Contractor  may  propose  alternate  detection  technology  (such  as  video  detection,  laser  based,
ultrasonic, infrared, and fibre optic based detection, etc) to inductive loop detection specified herein.
Contractor  shall  include  in  his  proposal  technical  justification  and  feasibility  of  the  proposed
technology  compared  with  the  specified  technologies.  Engineer  shall  review  the  proposed
technology and, if found suitable to this Project, shall forward his recommendations to the Owner for
approval. Contractor may not procure or deploy any alternate detection technology without obtaining
the Engineer approval in advance.

9.5.2.12

Local Intersection Traffic Signal Controllers and Associated
Equipment

Local intersection control equipment shall perform all functions necessary for the control of traffic
signals such as to safely assign rights-of-way to vehicular and pedestrian traffic. Intersection control
equipment shall be uniform throughout the Project unless otherwise approved by the Engineer.

Local control equipment shall include but not by way of limitation the following major components:

1.  Local intersection controller
2.  Local intersection controller cabinet
3.  Solid state load switches
4.  Security unit (conflict monitor)
5.  External flash device
6.  Communications interface unit as required to interface with the central computer control.
7.  Detector amplifier units

Descriptions  for  each  of  the  major  components  above  are  provided  herein  except  for  detector
amplifiers  which  are  described  earlier  in  Paragraph  1  of  Sub-article  a  of  Article  9.5.2.11.
Subcontractor  shall  provide  any  additional  equipment  necessary  to  make  the  system  perform  in

YSTEM

accordance with the object of the Contract, in full compatibility with the existing system, with good
traffic engineering practices, and to the approval of the Engineer.

a. Local Controllers

All local controllers shall be microprocessor based devices and shall provide equivalent functionality
of the legacy traffic signal controllers, or as shown on the Contract plans, required in the Particular
Specifications, approved by the Engineer and approved by the Owner.  Subcontractor shall supply
all  devices  necessary  to  fully  program  the  microprocessors  for  the  traffic  control  programs.    All
microprocessor memory shall be non-volatile.  Timing shall be digital in nature and based on a 50
hertz  supply  frequency.    All  controllers  shall  be  capable  of  fully  traffic  actuated  operation,  semi-
actuated operation or pre-timed operation.  Mode of operation shall be selectable at the controller
without  rewiring  or  without  the  need  for  special  tools.    Number  and  sequence  of  phases  at  each
intersection shall be as shown on functional drawings to be supplied by the Engineer, as required by
the traffic patterns and traffic volumes, and as approved by the Engineer.  Controllers shall include
all circuitry necessary to provide the specified phases and phase sequences.   Number of phases
and phase sequencing shall be selectable at the controller without the need for special tools.

Where necessary to ensure safe operation of the controller, a hardware watchdog timer shall be
provided. In the event the watchdog timer is not reset within a pre-set time period, the controller
shall be deactivated and the external flash device shall be activated.

It shall be possible to change controller timing parameters manually from the front of the controller
cabinet.  These changes shall be made either by inputs via the front panel of the controller or through
use of a portable readout device.  In the event a portable readout device is used it shall be connected
to the controller via a plug-in on the front panel.  In the event the portable readout device is used, a
minimum of two shall be provided.  All controllers shall provide the following features:

1. Signal indication sequence: Vehicular signal indication sequence shall be Green-Flashing

Green-Amber-Red-Green. No Amber indication shall appear between Red and Green
indications. Capability shall be included to provide all-red clearance intervals for each phase.
Pedestrian signal indication sequence shall be Green-Flashing Green-Red-Green.

2. Number of phases: Capability to accommodate a minimum of eight separate phases with

skip-phase capability shall be provided as directed by the Engineer (see Figure 9-1, the
numbers in Figure 9-1 indicate the phases).

3. Rings are timed independently but concurrently. Both rings must cross barriers

simultaneously. The controller shall comply with BS EN 12675, as approved by the Engineer,
and shall be housed in a matching traffic signal control cabinet. Controller type shall be
proven with at least one thousand units operating worldwide.

4. Controller shall be able to communicate via fibre optic transceivers using open

communication protocols (including IP). Proposed communications protocols between the
head-end traffic control system and the field controllers shall be submitted to the Engineer
for review and approval.

5. Cycle length range shall be 45 to 240 seconds, adjustable at 1 second steps.

YSTEM

control system at frequency ranges from 1 to 15 minutes. Controller shall store detector
counts and other vital data for a period of time in the case of communication failure with the
central control system. Type of data and duration of local storage shall be submitted to the
Engineer for review and approval. Grouping of detectors into one channel is not allowed.

7. Controller shall be equipped with a GPRS device to allow for wireless link with adjacent

controllers in case of failure to communicate with central control system. Controller shall be
capable  of  communicating  via  GPRS  with  the  central  unit  as  a  fixed  line  alternative  or  in
cases  of  fixed-line  communication  failure  with  the  central  unit.  Subcontractor  shall  be
responsible  for  GPRS  system  costs  including  subscription  with  local  telecommunications
providers, recurring fees and operating costs, and management costs during the construction
an operation phases of the Contract.

8. Controller shall be able to store 16 independent timing plans in a 24 hour period in its internal

memory, or in a memory expansion inside the controller cabinet.

9. Controller shall be able to store all data internally in the case of power failure without any

loss.

10. Controller shall be programmable via a local connection (LAN or serial links to a laptop) and

through the by central control system. All parameters and settings shall be possible to be
edited from the local and central connections.

11. Controller shall be able to accept sensor data from loop detectors, video detectors, radar

vehicle detectors (RVD), and other detection technologies as approved by the Engineer.
Additionally, it shall be possible to transmit images and video from the video detector to the
Control Centre without any measurable delay.

12. Controller shall contain control intelligence to optimize local parameters such as green time

adjustment and phase transitions inside the frame conditions received from the central
control system. For example, the controller shall be able to take local green light priority
requests into account without violating the global control strategy received from the central
control system.

13. Controller software shall have an open software architecture
14. Controller software shall calculate cycle lengths based on detector inputs as appropriate
15. Traffic controller software shall be easily upgradeable without removing or replacing the

controller

16. Controller software shall process detector data locally and shall calculate traffic density
17. Controller software shall allow definition of detectors as local and/or system types
18. Controller software shall provide a UTCS-compatible adaptive control mode. It shall

implement real time adaptive control without any new hardware components.

19. Controller software shall generate stage transitions automatically when in isolated mode as

appropriate

20. Controller software shall calculate cycle lengths based on detector inputs as appropriate
21. Controller software shall detect faults by monitoring all inputs and outputs every 10 seconds

or less

22. Controller shall categorize the faults and take the appropriate action(s)
23. Software shall organize groups (Signal groups) of vehicle movements into phases, intervals,

and sequences

24. To control Actuated operation, minimum intervals shall be set by users for each phase
25. Controller shall react to pedestrian and vehicular traffic demand in all phases
26. Controller shall rely on its timing tables and TOD and DOW clock. System-wide controller

clock update software shall be provided

27. Controller shall be suitable for the configuration of the intersection, with 50% spare capacity,

per the following:

Up to 4 signal groups.

ii.

Up to 16 signal groups.

iii.

Up to 32 signal groups.

28. Controller shall be suitable for the total number of vehicle loop detectors implemented at the

intersection, and shall be sized as follows with 50 % spare capacity.

Up to 16 vehicle loop detectors.

ii.

Up to 32 vehicle loop detectors.

YSTEM

iii.

Up to 64 vehicle loop detectors.

29. General I/O channels: the controller should be expandable to accommodate up to 48 general

inputs and up to 24 general outputs. I/O channels are equipped with terminals to hardwire
with hi and low logical states. The controller firmware should have the ability to create
programs utilizing the I/O channels for proper interface with different kind of devices (above
ground detection, pre-emption, TVR etc).

30. Controller shall have an ethernet port connection.
31. Controller should be capable to run the following type of signal time plans:

Fixed time plans.

ii.

Vehicle actuated time plans using ground loop detectors input and/or general I/O
inputs. Vehicle actuated time plans should be capable to extend individual green
phases on demand and/or skip green phase when no demand.

iii.

Provide pedestrian green on pushbutton demand only.

iv.

Provide minimum pedestrian green or more whenever it is not conflicting with
vehicular green.

Provide pedestrian green according to a fixed time schedule.

32. Lamp load monitoring: the controller should monitor the lamp load on all colours in each

group. Controller should be able to issue a warning or go to failure mode when lamp failure
is detected. When multiple lamps are monitored on the same group the controller should be
able to issue warning or go to failure mode based on the number of failed aspects. Lamp
monitoring should be possible for the range of 5W minimum to 100W maximum on each
colour in each group.

33. Log files: Controller should keep in its internal memory log files for the following:

Error log.

ii.

Event log.

iii.

Detector log.

iv.

Lamp log.

Plan log.

vi.

Historical temperature limits log.

vii.

Historical voltage limits log.

34. Controller shall keep in its internal memories traffic counts generated by the vehicle

detectors. Traffic count data should be kept in the controller memory for a period of 10 days.

35. Controller should be available in versions to work with a SCOOT, SCALA, SCATS,

OMNIA/UTOPIA and NTCIP central systems.

36. Traffic signal controller design: Traffic controller shall be designed for traffic signal control

and

shall include:

32-bit or greater microprocessor (to ensure currency of design submittals and long
term support for the traffic controller main component, the microprocessor, as follows:

ii.

A 32-bit or greater data and memory bus.

iii.

Adequate Dynamic RAM for the functions performed.

iv.

Adequate Flash RAM for the functions performed.

Flash Ram shall be capable of 100,000 Read/Write cycles without degrading.

vi.

1 MB minimum of Static RAM

vii.

Solid-state Real-Time Clock

viii.

Provision of authentication protocols to verify network connections.

ix.

Minimum 10 year parts and service availability from the manufacturer.

Serial communication ports (RS-232)

xi.

Ethernet interface ports (RJ45)

xii.

USB interface

xiii.

Integrated GPRS interface

xiv.

Assignment of functions to controller hardware contained herein represents only a
typical configuration. Alternative functional assignments are permitted.

37. Traffic controller shall be a modular design to facilitate rapid maintenance and repair.
38. T

raffic controller’s internal diagnostics shall be capable of identifying a controller fault to the

lowest replaceable unit (LRU), generally a replaceable module or printed circuit board.

Abu Dhabi, United Arab Emirates. STANDARD CONSTRUCTION SPECIFICATIONS (PART 1 - ROADS, Second Edition 2020) - page 51