ACTAR Practice Test

The ACTAR exam is for crash investigators and reconstructionists who want accreditation from the Accreditation Commission for Traffic Accident Reconstruction. It has a Theory portion of 75 questions and a Practical case problem with 25 questions and a scaled diagram. You need 75% on both. This page gives you the verified exam facts, free practice sets by topic, worked explanations and a study plan.

ACTAR Exam at a Glance

What the ACTAR is and how it works

According to Accreditation Commission for Traffic Accident Reconstruction, “The Practical portion consists of a case problem based upon a controlled collision, with a series of twenty-five (25) questions and a scaled diagram for analysis.”^[1]

ACTAR accreditation shows that a crash reconstructionist has met a shared standard set by the Accreditation Commission for Traffic Accident Reconstruction. Before you can sit the exam, the commission must approve your application. The review committee looks at your training, education and experience. It pays most attention to accident investigation, reconstruction or engineering courses you have finished with recognized industry providers.

The exam is taken in person with a proctor, on paper with a pencil. Computers are not allowed in the examination room. The Theory portion has 75 questions. The Practical portion is a case problem based on a controlled collision, with 25 questions and a scaled diagram to analyse. You get up to 4 hours per portion, 8 hours in total, with a lunch break between them. To be accredited you must score 75% or higher on both portions. Results can take up to 60 days and are reported as pass or fail only.

The application fee is $175 for members of a Participating Organization or $200 for non-members, and it is non-refundable. The examination fee is $75 for members or $125 for non-members. If you fail one portion, you retake only that portion within your 2-year eligibility period. If needed, you can request an additional 2-year period by paying the applicable fee. Accreditation lasts 5 years, and renewal requires 80 CEUs and a $325 fee. Exam dates and locations change, so check the calendar on actar.org before you book travel. The next listed sitting is Sunday, November 8, 2026, in Chicago, Illinois, before the Midwest Traffic Safety Conference.

ACTAR content outline and where to practise each area

The content areas below are copied from the official ACTAR content outline published by Accreditation Commission for Traffic Accident Reconstruction. The right-hand column shows which of our practice sets covers it.

Worked examples: how to reason through ACTAR questions

These are practice questions written for this site, not questions from the real exam. Each explanation shows why the right answer is right and why the others are wrong.

Example 1

Question: During a head-on collision between two vehicles of equal mass and equal speed, what happens to their combined momentum?

1. It doubles
2. It remains constant
3. It equals zero
4. It is transferred entirely to the heavier vehicle

Answer: C. It equals zero

Explanation:

Momentum is mass times velocity, and it has a direction. Vehicles of equal mass moving at equal speed toward each other have momenta of the same size but opposite sign, so the sum is zero. That makes option C correct.

• Option A treats momentum as if it had no direction. Speeds in opposite directions do not add up to a larger momentum.
• Option B sounds right because total momentum is conserved in a collision. But the question asks for its value, and the conserved value here is zero.
• Option D fails because the masses are equal, so there is no heavier vehicle. Momentum is also never handed entirely to one object.

Rule to remember: add momentum as vectors. Give each vehicle a sign or direction before you sum, and expect the total to be conserved, not each vehicle's share.

Example 2

Question: Which professional attribute is most valued in photogrammetry within the ACTAR field?

1. Working in isolation
2. Accountability and commitment to standards
3. Avoiding challenging situations
4. Prioritizing personal convenience

Answer: B. Accountability and commitment to standards

Explanation:

Option B is correct. Reconstruction work, including photogrammetry, produces measurements and opinions that other people rely on, so the practitioner has to own the method and follow accepted standards. Accountability means you can show how each measurement was taken, which photographs and reference points you used, and where the limits of the result are.

• Option A is wrong because working alone removes the peer checks that catch errors.
• Option C is wrong because difficult scenes and hard questions are part of the job. Avoiding them weakens the work.
• Option D is wrong because personal convenience is never a reason to change a procedure.

Rule to remember: in ethics and professional-practice questions, choose the answer that protects accuracy, transparency and the people who rely on your findings.

Example 3

Question: Which data representation is most appropriate for showing trends over time?

1. Pie chart
2. Line graph
3. Venn diagram
4. Tree diagram

Answer: B. Line graph

Explanation:

A line graph, option B, plots values against time on a continuous axis and joins the points, so rises, falls and turning points are easy to see.

• Option A, a pie chart, shows the parts of a single whole at one moment. It cannot show change over time.
• Option C, a Venn diagram, shows overlap between groups, not values that change.
• Option D, a tree diagram, shows branching outcomes or a hierarchy, such as probability paths. It has no time axis.

Rule to remember: match the chart to the question. Use a line graph for change over time, a pie chart for shares of a whole, a Venn diagram for overlap and a tree diagram for branching choices. The same idea applies when you plot speed or deceleration against time in a reconstruction.

How to use these practice tests

Start with the official ACTAR preparation guide and the exam page on actar.org, so you know how each portion is built and what the test-day rules are. Then take the practice test once without notes to see where you stand.

Next, work through the sets that match the official content areas. For physics and core principles, use Mathematical & Physical Principles and Vehicle Dynamics. For evidence, use Evidence Documentation & Interpretation, Scene Documentation and Vehicle Damage Analysis. For analytical methods, use Speed Calculations and Crash Dynamics. After each set, reread the explanation for every question you missed and write the formula or rule in your own notes.

The exam is on paper with no computers, so do every calculation by hand. Check the prep guide for which tools you may bring. To rehearse the Practical, work a case problem against a scaled diagram: measure, label and show your steps. Time some sessions in blocks of 4 hours so the length of a portion feels normal. In the last days before the exam, redo the sets where you scored lowest and stop adding new material.

Sources & last verified

1. Accreditation Commission for Traffic Accident Reconstruction — number of questions, passing score, retake policy, score release (official source). “The Practical portion consists of a case problem based upon a controlled collision, with a series of twenty-five (25) questions and a scaled diagram for…” Verified Oct 28, 2026.
2. Accreditation Commission for Traffic Accident Reconstruction — time limit, delivery (official source). “Candidates are allowed a maximum of four (4) hours per portion or eight (8) hours total with a break for lunch between portions.” Verified Oct 26, 2026 · source checked Oct 21, 2026.
3. Accreditation Commission for Traffic Accident Reconstruction — exam fee (official source). “the applicant must complete an application and remit an application fee of $175.00 US if the applicant is a member of one of the Participating…” Verified Oct 26, 2026 · source checked Oct 21, 2026.
4. Accreditation Commission for Traffic Accident Reconstruction — validity, renewal (official source). “A passing grade on both portions of the examination earns the participant a five year accreditation term.” Verified Oct 26, 2026 · source checked Oct 21, 2026.
5. Accreditation Commission for Traffic Accident Reconstruction — next exam date (official source). “Sunday, November 8, 2026 Location: Chicago, Illinois - Before the Midwest Traffic Safety Conference Sponsor: ACTAR” Verified Oct 26, 2026 · source checked Oct 21, 2026.
6. Accreditation Commission for Traffic Accident Reconstruction — eligibility (official source). “The application review committee will be looking for completion of industry recognized accident investigation and reconstruction, and/or engineering training courses, such as those offered by…” Verified Oct 26, 2026 · source checked Oct 21, 2026.

How we verify: editorial & fact-checking policy. Report an error: contact us.