CTSP Hazard and Risk Assessment 3

Question 1

In the ISA Tree Risk Assessment Qualification (TRAQ) framework, which three factors combine to determine overall tree risk?

Accepted Answer

Likelihood of failure, likelihood of impact, and consequences

Answer

TRAQ defines overall risk as the product of likelihood of failure, likelihood of impact on a target, and the consequences of that impact.

Question 2

Which condition would most likely place a tree into the 'Poor' structural condition rating?

Accepted Answer

Large open cavity occupying more than 30% of the trunk cross-section

Answer

A large open cavity removing more than 30% of the trunk's cross-sectional area severely compromises structural integrity.

Question 3

What is the primary purpose of establishing a tree risk tolerance threshold for a site?

Accepted Answer

To define the highest risk level acceptable before mitigation is required

Answer

A risk tolerance threshold defines the maximum acceptable risk level, triggering mitigation actions when that level is exceeded.

Question 4

A street tree with a significant lean over a sidewalk also shows root plate lifting on the tension side. What does root plate lifting indicate?

Accepted Answer

Active windthrow failure in progress or high failure potential

Answer

Root plate lifting signals that the tree's root system is losing anchorage and the tree may be in the early stages of windthrow failure.

Question 5

Which of the following best describes a 'residual risk' after mitigation measures have been applied?

Accepted Answer

The remaining risk that still exists after mitigation actions are completed

Answer

Residual risk is the level of risk that remains after mitigation measures such as pruning, cabling, or removal have been implemented.

CTSP - Certified Treecare Safety Professional Practice Test