KDOT Guardrail, Barriers & Safety Appurtenances 2

Question 1

What is the primary purpose of a crash cushion (attenuator) placed at the nose of a concrete barrier or rigid fixed hazard?

Accepted Answer

To absorb impact energy and decelerate a vehicle safely

Answer

To increase the visual profile of the hazard for drivers

Answer

To redirect vehicles parallel to the hazard

Answer

To provide a rumble-strip warning for approaching traffic

Question 2

What is the standard length of a single W-beam guardrail panel?

Accepted Answer

12 feet 6 inches

Answer

6 feet 3 inches

Answer

25 feet

Answer

50 feet

Question 3

When temporary concrete barrier (TCB) is used as a work zone divider on a KDOT project, what connection requirement applies at every joint?

Accepted Answer

Every joint must be pinned to prevent barrier separation during an impact

Answer

Joints are left open to allow water drainage

Answer

Only the end barriers at each run require pinning

Answer

Pinning is required only during nighttime work hours

Question 4

What corrosion protection standard typically applies to guardrail hardware (bolts, nuts, and washers) on KDOT projects?

Accepted Answer

Hot-dip galvanizing per ASTM A153 or equivalent

Answer

ASTM A325 high-strength bolts without coating

Answer

Two coats of rust-inhibiting primer paint

Answer

Stainless steel is the only acceptable material

Question 5

What is the purpose of a guardrail flare at a terminal location?

Accepted Answer

To gradually transition the rail away from the traveled way to reduce the probability of an end-on impact

Answer

To increase retroreflectivity of the guardrail end section

Answer

To connect the terminal directly to a bridge deck parapet

Answer

To mark the end of a construction zone for approaching drivers

Question 6

Who must approve any substitution of a non-standard or alternate guardrail end terminal on a KDOT project?

Accepted Answer

The KDOT project engineer

Answer

The prime contractor's foreman

Answer

The guardrail subcontractor's project manager

Answer

The county engineer for projects on county roads

Question 7

What characteristic of the New Jersey (NJ) profile concrete barrier makes it effective in work zone and median applications?

Accepted Answer

Its sloped lower face that redirects vehicle tires upward to reduce snagging and vaulting

Answer

Its ability to be repositioned by a single worker

Answer

Its built-in compatibility with thrie-beam rail transitions

Answer

Its lower cost compared to W-beam guardrail installations