KDOT Guardrail, Barriers & Safety Appurtenances 3

Question 1

What is the definition of 'working width' for a longitudinal barrier system?

Accepted Answer

The maximum lateral displacement of the barrier system during a crash test impact

Answer

The width of the construction zone protected by the barrier

Answer

The lane width adjacent to the installed barrier

Answer

The physical thickness of the barrier itself

Question 2

What inspection action should be taken immediately after a guardrail system has been struck by a vehicle during a construction project?

Accepted Answer

Document the damage and notify the KDOT project engineer for evaluation and repair authorization

Answer

Repaint all damaged rail sections and resume work without delay

Answer

Have the contractor replace only the visibly bent rail panel

Answer

Close the road until a federal FHWA safety inspection is completed

Question 3

What is the function of a breakaway base on sign posts and luminaire standards installed adjacent to the roadway?

Accepted Answer

To allow the post to separate from its foundation when struck, reducing injury risk to vehicle occupants

Answer

To provide electrical grounding for the post structure

Answer

To prevent vandalism by making the post harder to remove by hand

Answer

To permit seasonal rotation of the sign to an optimal orientation

Question 4

Under what primary condition does KDOT typically specify concrete median barrier (CMB) in place of W-beam guardrail for median protection?

Accepted Answer

When high traffic volumes and speeds make cross-median crashes potentially severe

Answer

When the median width exceeds 30 feet

Answer

When the contractor requests concrete for faster installation scheduling

Answer

When total project cost exceeds $1 million

Question 5

How is guardrail installation typically measured for payment on KDOT projects?

Accepted Answer

Per linear foot of complete guardrail system

Answer

Per post driven into the ground

Answer

Per ton of steel installed

Answer

Per crew day of installation work

Question 6

What must an inspector verify about guardrail anchor assemblies at the terminal ends of a guardrail run?

Accepted Answer

That they are properly installed per approved plans and securely embedded to resist pullout forces

Answer

That they are painted with high-visibility retroreflective paint

Answer

That they project above finished grade for visual identification

Answer

That they are removed after project construction is complete

Question 7

What is the primary difference between thrie-beam rail and standard W-beam rail in guardrail applications?

Accepted Answer

Thrie-beam has three corrugations providing higher containment capacity and better accommodation of curved alignments

Answer

Thrie-beam is made of aluminum while W-beam is galvanized steel

Answer

Thrie-beam is used only for temporary work zone applications

Answer

Thrie-beam is lighter and easier to handle than W-beam