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IMSA Signal Construction practice questions

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Question 1Plans, Specifications and Standards Interpretation

A traffic signal plan sheet shows a small circle with three radial lines inside an intersection layout, but the symbol is not one you recognize. Where should you look first on the same plan set to determine its meaning?

  1. The bill of materials
  2. The traffic signal cabinet wiring diagram
  3. The general specifications book
  4. The symbol legend or plan legend Correct answer.

Explanation

A plan legend is the key that assigns meanings to the graphic symbols used on the sheets. Cabinet wiring diagrams, specifications, and bills of materials may describe equipment, but they do not normally define plan symbols for the layout.

Question 2Plans, Specifications and Standards Interpretation

A signal plan title block is marked 'Revision 3' and carries a later date than the revision date on your printed set. What is the correct interpretation?

  1. Revision 3 supersedes earlier issues of this sheet. Correct answer.
  2. Revision 3 is a preliminary sheet and cannot be used for construction.
  3. The revision number refers to the third utility company affected.
  4. The later date means only the title block changed, not the work.

Explanation

A revision block identifies the current issued version of a plan sheet. When a later revision exists, it supersedes earlier issues of that sheet, and the contractor should work from the current contract set.

Question 3Plans, Specifications and Standards Interpretation

What is the primary purpose of as-built or record drawings prepared at the end of a traffic signal construction project?

  1. To replace the contract plans as the legal basis for the original bid
  2. To record actual installed locations, materials, and field changes Correct answer.
  3. To provide a preliminary design for a future signal at the same intersection
  4. To document only the contractor's pay quantities for the final estimate

Explanation

As-built or record drawings document what was actually installed, including field changes, buried conduit routing, and equipment locations. They support future maintenance and locating work, and they do not replace the contract plans for the original bid.

Question 4Plans, Specifications and Standards Interpretation

A conduit schedule on a traffic signal plan lists an item as '4-3 in. PVC.' In standard plan notation, what does this entry describe?

  1. Three conduits, each 4 inches in diameter
  2. Four conduits installed at 3-foot spacing
  3. A 4-inch conduit with 3 inches of cover
  4. Four conduits, each 3 inches in diameter Correct answer.

Explanation

Conduit schedules commonly use a count-dash-size notation, so '4-3 in.' means four conduits of 3-inch diameter. It does not describe spacing, cover, or a single 4-inch conduit.

Question 5Plans, Specifications and Standards Interpretation

On a NEMA-based traffic signal phasing diagram, phase 2 and phase 6 are shown as concurrent. What does this indicate about the intersection operation?

  1. Phase 6 is a pedestrian phase that runs only with phase 2.
  2. Phase 2 and phase 6 must always be separated by an all-red interval.
  3. The opposing through movements on the main street may run together. Correct answer.
  4. The two left-turn movements on the cross street may run together.

Explanation

In NEMA phasing, phases 2 and 6 are the opposing through phases for the main street. Showing them as concurrent means those compatible through movements can time together; it does not refer to cross-street left turns or a pedestrian-only phase.

Question 6Plans, Specifications and Standards Interpretation

A contract's order-of-precedence clause lists, from highest to lowest: (1) special provisions, (2) plans, (3) standard specifications, (4) standard details. A plan dimension conflicts with a standard detail dimension. Which document governs?

  1. The contractor may choose whichever dimension is less costly
  2. The plans, because they rank above standard details Correct answer.
  3. The standard detail, because details are more specific than plans
  4. The standard specifications, because they define workmanship

Explanation

An order-of-precedence clause is applied exactly as written in the contract. Because plans are listed above standard details in the stated hierarchy, the plan dimension governs the conflict.

Question 7Plans, Specifications and Standards Interpretation

A plan sheet is drawn at a scale of 1 inch equals 20 feet. A scaled measurement between two pull boxes is 3.5 inches. What is the actual distance?

  1. 60 ft
  2. 35 ft
  3. 140 ft
  4. 70 ft Correct answer.

Explanation

At a scale of 1 inch equals 20 feet, each inch on the sheet represents 20 feet in the field. Multiplying 3.5 inches by 20 feet per inch gives 70 feet.

Question 8Plans, Specifications and Standards Interpretation

A signal plan specifies 8-inch diameter signal lenses for a through movement on an approach with a posted speed limit of 45 mph. How should the inspector interpret this against the MUTCD minimum lens-size requirement?

  1. It is acceptable because 8-inch lenses are allowed on all through movements.
  2. It is acceptable if the approach has only one through lane.
  3. It is noncompliant; 8-inch lenses are not allowed at 45 mph. Correct answer.
  4. It is acceptable if the signal faces are mounted on a mast arm.

Explanation

The MUTCD restricts 8-inch signal lenses to low-speed approaches, generally those posted at 30 mph or less. On a 45 mph approach, 12-inch lenses are required, so the plan detail should be corrected before construction.

Question 9Plans, Specifications and Standards Interpretation

A contractor submits a shop drawing for a signal controller that is not the model named in the specifications. The shop drawing is stamped 'approved for construction' by the contractor's project manager but has no engineer or owner approval. What is the proper construction decision?

  1. Install it only if the controller is less expensive than the specified model.
  2. Do not install it; obtain written approval of the substitution first. Correct answer.
  3. Install it, because the contractor's approval stamp makes the shop drawing contractually binding.
  4. Install it, because shop drawings always take precedence over the specifications.

Explanation

Shop drawing approval by the contractor does not authorize a substitution for a specified product. A product substitution must be processed and approved in writing through the contract's submittal or change-order procedure before installation.

Question 10Plans, Specifications and Standards Interpretation

A signal plan wiring schedule shows '3-#8 THHN' for a circuit. What does the '3' indicate?

  1. Three-phase power circuit
  2. Three-foot conductor length
  3. Three current-carrying conductors Correct answer.
  4. Three-inch conduit trade size

Explanation

In conductor notation such as 3-#8 THHN, the leading number is the quantity of conductors and the number after the dash is the AWG size. The '3' therefore indicates three conductors, not a conduit size or circuit length.

Question 11Plans, Specifications and Standards Interpretation

On a traffic signal plan, a graphic bar scale is printed beside the numerical scale note. If the sheet is reproduced at 75 percent of its original size, why does the bar scale remain usable for scaling dimensions?

  1. Because the bar converts inches to feet with a fixed multiplier printed above it
  2. Because the bar shows the elevation change along the conduit run
  3. Because the bar indicates the north direction for the intersection layout
  4. Because the bar shrinks in the same proportion as the drawing features Correct answer.

Explanation

A graphic bar scale represents a known distance by a drawn length, so when the entire sheet is reduced both the bar and the mapped features change by the same factor. A numerical scale such as 1 in. = 20 ft is no longer true after reduction unless it is adjusted. The bar therefore remains the reliable field-check scale.

Question 12Plans, Specifications and Standards Interpretation

A traffic signal specification states: 'The Contractor shall provide a surge protective device at the service entrance.' In contract documents, how should the word 'shall' be interpreted?

  1. As a permission allowing the Contractor to omit the device
  2. As a goal enforced only after a surge-related failure
  3. As a recommended practice the Contractor may follow at its option
  4. As a mandatory requirement the Contractor must satisfy Correct answer.

Explanation

In construction specifications, 'shall' creates a mandatory obligation; 'should' or 'may' indicate a recommendation or permission. The Contractor must furnish and install the device to be compliant.

Question 13Plans, Specifications and Standards Interpretation

A traffic signal plan calls for '2 in. RGS' conduit on the service entrance. What does the abbreviation RGS identify?

  1. Reinforced gray PVC
  2. Red-jacketed signal duct
  3. Rigid galvanized steel Correct answer.
  4. Ribbed flexible polyethylene

Explanation

RGS is the standard abbreviation for rigid galvanized steel conduit, a common raceway for exposed signal service and risers. PVC would be designated as PVC, and flexible raceways use different abbreviations.

Question 14Plans, Specifications and Standards Interpretation

A plan shows an overhead vehicle signal face with its bottom at 17 ft above the roadway crown on a 45 mph approach. Which document normally establishes the minimum mounting height for that signal face?

  1. NEC Article 725
  2. IMSA 19-1
  3. MUTCD Part 4 Correct answer.
  4. ASME B30.5

Explanation

The MUTCD Part 4 establishes traffic signal design and mounting requirements, including minimum height of signal faces over the roadway. The NEC addresses electrical wiring methods, IMSA 19-1 covers cable performance, and ASME B30.5 addresses mobile cranes.

Question 15Plans, Specifications and Standards Interpretation

During bid review, a contractor finds that the conduit schedule lists 1,100 ft of 2-inch conduit for a run while the plan quantity sheet lists 1,250 ft for the same run. The specifications are silent on quantity discrepancies. What is the most appropriate action before bid submission?

  1. Ignore the difference because conduit is paid as a lump sum
  2. Bid the higher quantity and install only what the schedule shows
  3. Bid the lower quantity because the schedule is more detailed
  4. Submit a request for information to the engineer Correct answer.

Explanation

When contract documents conflict and no precedence rule resolves the item, the contractor should seek written clarification through an RFI before bidding. Selecting either quantity unilaterally transfers avoidable risk and may not match the engineer's intent.

Question 16Plans, Specifications and Standards Interpretation

A signal plan shows a rectangular loop detector 6 ft wide by 24 ft long. The specification requires three turns of wire in the saw cut. Excluding the lead-in cable, what length of loop wire is required?

  1. 60 ft
  2. 120 ft
  3. 540 ft
  4. 180 ft Correct answer.

Explanation

The loop perimeter is 2 × (6 ft + 24 ft) = 60 ft. Three turns require 3 × 60 ft = 180 ft of wire, with lead-in excluded as stated.

Question 17Plans, Specifications and Standards Interpretation

An IMSA 19-1 signal cable is specified with color-coded conductors. What is the primary purpose of that color coding?

  1. To mark which conductors are reserved as future spares
  2. To indicate the insulation voltage rating of each conductor
  3. To show the direction of current flow in each circuit
  4. To identify conductor functions and aid troubleshooting Correct answer.

Explanation

IMSA 19-1 assigns conductor colors to signal circuit functions, which helps technicians terminate and troubleshoot consistently. The colors do not encode voltage rating, current direction, or spare status.

Question 18Plans, Specifications and Standards Interpretation

A plan note places a pull box at 'Station 12+50, 8 ft LT.' The baseline is the roadway centerline. What does this notation indicate?

  1. A location 1,250 ft along the baseline and 8 ft left of it Correct answer.
  2. A location 12.5 ft along the baseline and 8 ft left of it
  3. A location 125 ft along the baseline and 8 ft left of it
  4. A location 1,250 ft from the nearest intersection and 8 ft above grade

Explanation

In stationing, 12+50 means 1,200 ft plus 50 ft, or 1,250 ft from the baseline origin. The suffix LT means the point is offset 8 ft to the left of the baseline.

Question 19Plans, Specifications and Standards Interpretation

The signal specifications require heads meeting a listed photometric performance standard and permit 'approved equal' substitutions. A contractor proposes a head of the same physical size but with lower candela output. What must the contractor demonstrate for the substitution to be considered?

  1. That the proposed head has been used at another intersection in the state
  2. That the proposed head is manufactured by the same company as the specified controller
  3. That the proposed head meets all specified performance and dimensional criteria Correct answer.
  4. That the proposed head costs less than the specified model

Explanation

An approved-equal substitution requires the contractor to show equivalence to the specified product in performance, materials, and dimensions, and to obtain the engineer's acceptance. Lower candela output fails the photometric requirement even if the size matches.

Question 20Plans, Specifications and Standards Interpretation

A specification requires the signal cabinet grounding electrode system to have a resistance to earth not exceeding 25 ohms. A test after installation reads 40 ohms. What is the most appropriate next step?

  1. Increase the controller surge protection rating to compensate for the resistance
  2. Improve the electrode system, such as by adding ground rods, and retest Correct answer.
  3. Disconnect the equipment ground and retest to isolate the service neutral
  4. Accept the reading because 40 ohms is within the NEC maximum for signal cabinets

Explanation

The 25-ohm value is a contractual limit, so a 40-ohm result does not comply. The contractor should modify the electrode system-for example, by adding rods or a ring-and retest until the specified resistance is achieved.

Question 21Plans, Specifications and Standards Interpretation

A traffic signal specification requires opaque backplates on all vehicle signal heads. In signal construction, what is the primary purpose of the backplate?

  1. To prevent water from entering the signal housing
  2. To reduce electrical interference on signal conductors
  3. To support the signal head from the mast arm
  4. To improve conspicuity against complex backgrounds Correct answer.

Explanation

Backplates provide a dark surround that increases contrast between the illuminated signal indication and the background, making the signal easier to detect. They are not a structural support, a weather seal, or an electrical-noise control measure.

Question 22Plans, Specifications and Standards Interpretation

A signal plan places a steel strain pole in the roadside clear zone and specifies a breakaway transformer base at its foundation. What is the intended function of this base?

  1. To isolate the pole electrically from the foundation to control corrosion of the base
  2. To let the pole separate or tip away when struck, reducing impact severity Correct answer.
  3. To permit the pole to be rotated for aiming after installation
  4. To damp vibration from span wire and signal heads

Explanation

A breakaway base is a frangible foundation connection designed to yield when a vehicle strikes the pole, allowing the pole to separate or tip and reducing the severity of the impact. Electrical isolation, vibration damping, and post-installation rotation are not its intended functions.

Question 23Plans, Specifications and Standards Interpretation

A traffic signal specification requires a controller assembly conforming to NEMA TS 2. Which subject is primarily covered by that standard?

  1. Dimensions and placement of pedestrian push-button signs
  2. Color-code assignments for signal and detector conductors
  3. Minimum photometric performance of vehicle signal lenses
  4. Functional and environmental requirements for controller assemblies Correct answer.

Explanation

NEMA TS 2 establishes functional, environmental, and communications performance requirements for traffic control controller assemblies, including the cabinet and associated equipment. Conductor color coding, lens photometrics, and push-button sign layout are covered by other standards or manuals.

Question 24Plans, Specifications and Standards Interpretation

A specification requires shielded twisted-pair lead-in cable for inductive loop detectors. What field condition is this requirement primarily intended to address?

  1. Mechanical abrasion where cable enters the cabinet
  2. Corrosion at the loop wire splices
  3. Voltage drop on long loop runs
  4. Electrical noise induced on the detector circuit Correct answer.

Explanation

Twisting the pair and adding a shield reduce the pickup of electromagnetic interference on the low-level detector circuit, which can otherwise cause false calls or dropped calls. The cable construction does not seal splices, resist abrasion at the cabinet entry, or correct voltage drop.

Question 25Plans, Specifications and Standards Interpretation

A signal pole foundation detail specifies anchor bolts conforming to ASTM F1554 Grade 36. In that designation, what does Grade 36 primarily indicate?

  1. A minimum yield strength of 36 ksi Correct answer.
  2. A maximum overall length of 36 inches
  3. A minimum bolt diameter of 3/4 inch
  4. A hot-dip galvanized coating thickness of 36 mils

Explanation

In ASTM F1554, the grade number denotes the minimum yield strength in ksi; Grade 36 anchor bolts have a specified minimum yield strength of 36 ksi. Diameter, coating thickness, and length are separate dimensions or coating requirements, not the grade designation.

Question 26Plans, Specifications and Standards Interpretation

A signal timing sheet shows a pedestrian clearance interval of 15 seconds for a crossing 60 ft wide, based on a 4.0 ft/s walking speed. The agency specification requires the MUTCD default walking speed for pedestrian clearance. What is the correct interpretation?

  1. Too short; 3.5 ft/s gives about 17.1 seconds Correct answer.
  2. Too long; the MUTCD default walking speed is 5.0 ft/s
  3. Acceptable, because 4.0 ft/s is the MUTCD default walking speed for all crossings
  4. Unaffected, because walking speed applies only to the WALK interval

Explanation

The MUTCD default walking speed for calculating pedestrian clearance is 3.5 ft/s, so a 60-ft crossing requires about 17.1 seconds (60 divided by 3.5). The 15-second interval based on 4.0 ft/s is therefore shorter than the default calculation.

Question 27Intersection Layout, Staking and Foundation Work

In signal pole staking, why are offset stakes set outside the foundation excavation limits instead of relying only on the pole center stake?

  1. They establish the finished grade around the completed foundation.
  2. They preserve the reference after the center stake is removed. Correct answer.
  3. They mark the exact center of the anchor bolt circle for the template.
  4. They show the required radius of the conduit sweep at the pole base.

Explanation

Offset stakes are set beyond the excavation and referenced to the plan baseline so the pole center can be re-established after the center stake is removed. Without them, digging destroys the only field mark for the foundation location.

Question 28Intersection Layout, Staking and Foundation Work

Which item is used to hold signal pole anchor bolts in the correct bolt-circle pattern while foundation concrete is placed?

  1. Anchor bolt template Correct answer.
  2. Ground rod clamp
  3. Rebar chair
  4. Conduit sweep

Explanation

An anchor bolt template is a rigid jig that holds the bolts at the specified bolt-circle diameter and spacing while concrete cures. It also helps keep the bolts plumb and at the required projection above the foundation.

Question 29Intersection Layout, Staking and Foundation Work

When laying out a signal pole from the approved plans, the dimensions are normally referenced to which feature?

  1. the right-of-way line or curb return shown on the plans Correct answer.
  2. the contractor's chosen construction entrance
  3. the nearest existing utility pole or guy anchor
  4. the center of the traveled way at the nearest painted stop bar

Explanation

Plan dimensions for signal poles are tied to a defined baseline such as a right-of-way line, curb return, or station and offset. Using a field feature that is not on the plans introduces error and can change clearances.

Question 30Intersection Layout, Staking and Foundation Work

Before excavating a signal foundation in a public right-of-way, the crew should take which action?

  1. notify the utility companies after the hole is open
  2. assume utilities are deeper than the foundation excavation
  3. confirm utility locates are complete and marked Correct answer.
  4. begin digging at the offset stake and stop if a utility is hit

Explanation

Excavation in a right-of-way can strike gas, electric, water, or communications lines. Utility locates must be requested and the markings confirmed before digging; hitting a line and then stopping is not an acceptable locate process.

Question 31Intersection Layout, Staking and Foundation Work

Why is a large-radius conduit sweep required at the bottom of a signal pole foundation?

  1. To make the conduit easier to cut off at finished grade
  2. To let conductors be pulled without damaging insulation Correct answer.
  3. To provide a bonding point for the grounding electrode
  4. To reduce the amount of concrete needed in the foundation

Explanation

Conductors have a minimum bend radius, and a sharp elbow can damage insulation or jam a pull. A large-radius sweep provides a gradual transition from the horizontal run to the vertical stub at the pole.

Question 32Intersection Layout, Staking and Foundation Work

A signal foundation is completed with the top of the concrete slightly above surrounding finished grade. What is the main reason for this detail?

  1. to increase the anchor bolt projection above the base plate
  2. to allow the pole to be plumbed with shims
  3. to keep water from ponding at the pole base Correct answer.
  4. to meet the minimum conduit burial depth for the site

Explanation

Raising the foundation top slightly above grade sheds runoff and prevents water from standing around the base plate and anchor bolts. Standing water accelerates corrosion and can freeze, loosening the anchor bolts.

Question 33Intersection Layout, Staking and Foundation Work

When setting the anchor bolt template for a mast arm pole, the template orientation should be:

  1. aligned with the nearest curb line regardless of what the plans show
  2. set to true north
  3. aligned to the plan orientation of the mast arm Correct answer.
  4. rotated so the conduit stubs face the controller cabinet

Explanation

The anchor bolt pattern fixes the rotational orientation of the pole base, so the template must be set to match the plan direction of the mast arm and signal faces. Rotating it later is not possible without replacing or modifying the foundation.

Question 34Intersection Layout, Staking and Foundation Work

A rectangular foundation is staked with all four corners and side dimensions correct, but the corners may not be square. Which field check best confirms the layout is square?

  1. Compare the two diagonal measurements; they should be equal. Correct answer.
  2. Check that opposite sides are parallel by eye.
  3. Verify that one corner is 90 degrees with a small speed square.
  4. Measure the perimeter and divide by four.

Explanation

For a rectangular layout, equal diagonals confirm that the corners are square; equal side lengths alone can still produce a skewed rhombus. A small framing square is not accurate enough for a foundation-scale check.

Question 35Intersection Layout, Staking and Foundation Work

During layout, a signal pole location conflicts with an existing water main that is not shown on the plans. What is the correct action?

  1. Shift the pole along the curb until it clears the main and proceed.
  2. Stop in that area and request a directed revision from the engineer. Correct answer.
  3. Set the pole on a smaller foundation to avoid the main.
  4. Break out the main and reroute it without documentation.

Explanation

Unforeseen utilities require a documented field revision because moving the pole can affect clearances, structural design, and signal visibility. The crew should stop in that area and route the conflict to the engineer or inspector.

Question 36Intersection Layout, Staking and Foundation Work

A grounding electrode is installed at a signal pole foundation. Where is it typically connected?

  1. to the adjacent concrete curb and gutter section
  2. to the conduit sweep only
  3. to the rebar chair
  4. to the pole, anchor bolts, and equipment ground Correct answer.

Explanation

The grounding electrode at a pole foundation is bonded to the pole or its anchor bolts and to the equipment grounding conductor. This creates a low-impedance fault path and ties the structure into the site grounding system.

Question 37Intersection Layout, Staking and Foundation Work

Underground conduit for a signal installation crosses beneath a public roadway. Absent a stricter local specification, what is the minimum cover required over the conduit at the roadway surface?

  1. 24 inches Correct answer.
  2. 6 inches
  3. 12 inches
  4. 18 inches

Explanation

NEC Table 300.5 sets 24 inches of cover for rigid conduit beneath streets, highways, and parking lots. A local agency specification may require deeper cover, in which case the stricter requirement governs the installation.

Question 38Intersection Layout, Staking and Foundation Work

The exact plan location of a signal pole is typically marked in the field by:

  1. a hub with a tack marking the point Correct answer.
  2. a wooden grade stake driven flush with the ground
  3. a survey flag placed at the offset distance
  4. a painted circle on the pavement surface

Explanation

The hub is set at the calculated plan point, and a tack in its top marks the exact location used to stretch lines and measure offsets. Grade stakes, paint, and offset flags serve other purposes in the layout.

Question 39Intersection Layout, Staking and Foundation Work

When a signal foundation must be installed in an existing paved roadway, the pavement is typically sawcut:

  1. exactly to the foundation dimensions with no allowance
  2. after digging, along the broken edge
  3. only at the four corners of the foundation
  4. in straight lines outside the excavation limits Correct answer.

Explanation

Sawcutting ahead of excavation produces a clean, straight joint outside the work limits, prevents pavement raveling, and gives a defined edge for restoration. Cutting after digging leaves a jagged, uncontrolled break.

Question 40Intersection Layout, Staking and Foundation Work

Before a signal pole is erected on a new foundation, the concrete must:

  1. be at least 24 hours old
  2. reach the strength specified by the engineer Correct answer.
  3. have all formwork removed
  4. be dry to the touch at the surface

Explanation

Foundation concrete must attain the compressive strength specified by the engineer before it is loaded by pole erection. Cylinder breaks or maturity methods confirm strength; elapsed time alone is not acceptance.

Question 41Intersection Layout, Staking and Foundation Work

An excavation for a signal foundation will be 6 feet deep with near-vertical walls. OSHA requires:

  1. a protective system such as sloping or shoring Correct answer.
  2. a flagger stationed at the top of the hole
  3. no protection if the hole is open only one day
  4. a ladder placed every 50 feet

Explanation

OSHA 29 CFR 1926 Subpart P requires a protective system for excavations 5 feet or deeper where there is no stable rock. Sloping, shoring, or a trench box protects workers from cave-in.

Question 42Intersection Layout, Staking and Foundation Work

The bottom of a signal foundation excavation reveals soft, unsuitable material. The typical corrective action is to:

  1. place loose gravel and proceed without compaction
  2. shorten the foundation so it bears above the soft layer
  3. pour the footing concrete directly on the soft material as found
  4. over-excavate and backfill with compacted approved material Correct answer.

Explanation

Soft or unsuitable bearing material must be removed and replaced with approved, compacted backfill so the foundation bears on firm soil. Pouring on soft material risks settlement and rotation of the pole.

Question 43Intersection Layout, Staking and Foundation Work

A signal pole is installed beside a public sidewalk. To preserve accessibility, the pole and foundation must not reduce the clear pedestrian route below:

  1. 24 inches
  2. 60 inches
  3. 36 inches
  4. 48 inches Correct answer.

Explanation

Accessibility standards such as PROWAG require a continuous clear pedestrian access route, generally at least 48 inches wide. A pole placed in the sidewalk must not pinch the route below that minimum.

Question 44Intersection Layout, Staking and Foundation Work

During the concrete pour, conduit stub-ups at a signal foundation should be:

  1. plugged with loose sand only
  2. capped and secured in position Correct answer.
  3. left open to drain any water
  4. removed until the concrete cures

Explanation

Stub-ups must be capped and braced so concrete, slurry, or debris cannot enter the conduit and so the conduits stay in their planned position. Open or unsecured conduits can be displaced or plugged during the pour.

Question 45Intersection Layout, Staking and Foundation Work

A signal foundation is designed with its top at elevation 812.50 ft. The contractor over-excavates 12 inches below the design bottom to remove unsuitable soil and replaces it with compacted granular backfill. After the foundation is poured to the plan dimensions, the top of the foundation should be:

  1. at 812.50 ft, unchanged Correct answer.
  2. 12 inches higher at 813.50 ft
  3. 12 inches lower at 811.50 ft
  4. at 812.00 ft, halfway between

Explanation

Over-excavation and replacement restore the design bearing elevation but do not change the plan top elevation. The foundation is still poured to the plan depth and top, so the finished top remains at 812.50 ft.

Question 46Intersection Layout, Staking and Foundation Work

After a signal foundation cures, one anchor bolt is found 1/2 inch outside its specified position. The proper action is to:

  1. notify the engineer and use an approved method Correct answer.
  2. cut the bolt off and ignore it
  3. bend the bolt into position with a pipe
  4. enlarge the pole base plate holes without approval

Explanation

Anchor bolts are structural and must not be field-bent, because bending can crack or yield them and reduce capacity. Any correction, such as slotting or epoxy anchors, requires engineer approval.

Question 47Intersection Layout, Staking and Foundation Work

A signal pole is called out on the approved plans at station 16+42.0. Measured from the project baseline origin, this location is:

  1. 164.2 feet
  2. 1,642.0 feet Correct answer.
  3. 1,064.2 feet
  4. 16,420 feet

Explanation

Station notation uses 100-foot stations, so 16+42.0 means 16 full stations of 100 feet plus 42.0 feet, or 1,642.0 feet from the baseline origin. The plus sign separates full stations from the remaining distance and is not a decimal point.

Question 48Intersection Layout, Staking and Foundation Work

A benchmark at elevation 824.00 ft is sighted with a level and the rod reads 3.50 ft. What rod reading is needed to set the top of a signal foundation at elevation 826.20 ft?

  1. 5.70 ft
  2. 2.20 ft
  3. 3.50 ft
  4. 1.30 ft Correct answer.

Explanation

The height of instrument equals the benchmark elevation plus the backsight rod reading: 824.00 + 3.50 = 827.50 ft. The foresight needed for the foundation top is the height of instrument minus the design elevation: 827.50 - 826.20 = 1.30 ft.

Question 49Intersection Layout, Staking and Foundation Work

After a signal foundation in a grass parkway has cured and the forms have been removed, the excavation around it should normally be backfilled by:

  1. placing approved backfill and compacting it in lifts Correct answer.
  2. flooding the excavation until the soil settles
  3. leaving the excavation open for the landscape contractor
  4. backfilling with excavated wet clay in a single lift

Explanation

Foundation backfill in a parkway must be placed in thin lifts and compacted to the specified density so it will not settle and leave a dip around the pole. Flooding or dumping saturated clay in one lift cannot achieve the required compaction and creates a future maintenance problem.

Question 50Intersection Layout, Staking and Foundation Work

A signal foundation is 4.0 ft by 4.0 ft in plan and 8.0 ft deep. Allowing 10 percent for waste, how much concrete should be ordered?

  1. 5.2 cubic yards Correct answer.
  2. 4.7 cubic yards
  3. 6.0 cubic yards
  4. 5.7 cubic yards

Explanation

The neat volume is 4.0 x 4.0 x 8.0 = 128 cubic feet, which is 128 / 27 = 4.74 cubic yards. Adding 10 percent for waste gives 4.74 x 1.10 = 5.21 cubic yards, so 5.2 cubic yards should be ordered.