Tree risk assessment: TRAQ, QTRA, VTA and the other methods

Tree risk work is a different job from climbing and cutting. The methods below are run by different bodies and sit under different rules in each country. This page describes what the official pages say.

United States

ISA Tree Risk Assessment Qualification (TRAQ)

ISA calls TRAQ a voluntary qualification program. To earn it you complete a training course and pass a written assessment and a performance-based assessment. The page says the full program is a two-day course followed by a half-day of assessments. Everyone who registers gets a copy of the Tree Risk Assessment Manual and a course workbook.

ISA says successful candidates are proficient with the fundamentals of limited-visual and basic tree risk assessment, as defined in ISA's Best Management Practices: Tree Risk Assessment. They also understand the principles of advanced diagnostic techniques.

The eligibility list on the same page includes these ISA credentials.

ISA Certified Arborist, ISA Board Certified Master Arborist and ISA Certified Urban Forest Professional.
ISA Certified Arborist Utility Specialist and ISA Certified Tree Climber.
Other paths: a degree in arboriculture, urban forestry, forestry or horticulture, a national certificate in arboriculture, or an approved licensing or certification granted by a state or province.

The TRAQ program guide, revised July 2026, says the credential is valid for seven years. Reinstating it after each seven-year period requires retraining and retesting. For people who need to apply to become eligible, the guide lists an application fee of US$40 for ISA members and US$50 for everyone else. Retaking an exam costs US$120 per exam for up to one year from the original program start date. Course prices are set by the host. See the TRAQ program guide.

ISA's BMP for tree risk assessment is a separate publication. Its third edition (2025) lists levels of tree risk assessment among its topics and costs US$19.95 for ISA members and US$25.95 for everyone else.

Canada

TRAQ is also given in Canada. ISA Ontario's TRAQ page describes a two and a half day course followed by a half-day assessment. It says that to take the course you must hold or have previously held an approved credential, and give proof of it. The page says dates and locations for 2026 are to be announced later.

United Kingdom

QTRA

QTRA is the Quantified Tree Risk Assessment method, developed by Mike Ellison at Cheshire Woodlands. The QTRA page says it moves tree safety management away from labelling trees as either safe or unsafe, and quantifies the risk of harm from tree failure instead. It looks first at the use of the land under the tree, the target, and then at the tree. The page publishes advisory thresholds: a risk of 1 in 1,000 is unacceptable where imposed on others, 1 in 10,000 is tolerable where imposed on others, and 1 in 1,000,000 is broadly acceptable.

To use the method you become a Registered User. The Registered User page says users must attend a training workshop. It describes both a one-day workshop and a two-day workshop capped at 20 delegates. Users get a manual, sample documents and a calculator, plus updates during the registration period. The page says registration is not restricted to arborists, and that the training gives no guidance on assessing tree stability. A course price and the length of a registration period are not on that page.

National Tree Safety Group guidance

The National Tree Safety Group handbook is not a credential. Its summary says it was first published by the Forestry Commission in 2011, and the second edition was published by Forest Research and the Arboricultural Association in 2024. Its strategy has three parts: zoning, which relates tree stock to people and property, tree checking, which assesses obvious defects, and managing risk at an acceptable level.

The glossary in the full NTSG guidance document defines visual tree assessment (VTA) as a tree inspection method using observation of visual signs, to aid diagnosis of tree health and structural condition within its immediate setting. It defines a walk-over assessment as an on-foot method for checking trees from accessible viewpoints. It also cites Lantra and Arboricultural Association tree inspection courses.

Lantra Professional Tree Inspection

On its Professional Tree Inspection page, Lantra describes a programme for experienced arboriculturists. A pass earns a Lantra Awards Professional Tree Inspection Certificate of Competence. Lantra says the programme exists because tree assessment practice has been examined after court cases and inquests where trees with a foreseeable defect failed. Assessment has four sections: a closed-book short answer paper, a scenario paper, a fungi, pest and pathogen test, and two tree inspection exercises written up as inspection records. Lantra lists the courses by training provider.

Australia

The Institute of Australian Consulting Arboriculturists, on its home page, says its Accredited Members are AQF Level 5 or equivalent qualified consulting arborists, with no involvement in tree removal or pruning. It says most councils ask for arboricultural reports from practitioners at that level, and that members renew every year. This is a membership, not a risk method.

New Zealand

NZ Arb hosts ISA TRAQ courses. Its TRAQ page says ISA owns and develops the qualification, and that the course is two days plus a half-day assessment with a written and a field part. It says TRAQ 3.0 launched in November 2025, with no separate renewal course, a credential valid for seven years instead of the earlier five, and applications through ISA's credentialing portal. An approved application is needed before registration.

At a glance

Method	Run by	Length or term
TRAQ	ISA	2 days plus a half-day assessment; 7 years
QTRA	QTRA Ltd	1 or 2 day workshop; registration period
Professional Tree Inspection	Lantra	Certificate of Competence
NTSG guidance	NTSG	Handbook, 2024 edition
IACA accreditation	IACA	Renewed every year

For how pruning is described in standards, see pruning standards by country. For other credentials, see certifications by country.