DOT Accident Investigation & Reporting 3 — Questions and Answers
Question 1: When interviewing witnesses at an accident scene, which interviewing technique is most appropriate for a DOT investigator?
- Ask leading questions to confirm the investigator's initial theory
- Separate witnesses and conduct individual interviews to avoid influence (Correct answer)
- Interview all witnesses together to save time
- Allow witnesses to review each other's statements before signing
Correct answer: Separate witnesses and conduct individual interviews to avoid influence
Witnesses must be interviewed separately to prevent their accounts from being influenced by other witnesses' statements.
Question 2: A driver involved in a fatal accident refuses a post-accident drug and alcohol test. Under FMCSA regulations, what is the consequence?
- The driver receives a written warning only
- The carrier must remove the driver from safety-sensitive functions (Correct answer)
- The driver may postpone testing for 24 hours
- No action is required unless a court orders testing
Correct answer: The carrier must remove the driver from safety-sensitive functions
Under 49 CFR Part 382, a driver who refuses post-accident testing must be immediately removed from safety-sensitive functions.
Question 3: What is the maximum time window after a fatal accident within which a driver must complete a post-accident alcohol test under 49 CFR 382.303?
- 4 hours
- 8 hours (Correct answer)
- 12 hours
- 24 hours
Correct answer: 8 hours
Post-accident alcohol testing must be completed within 8 hours of the accident; otherwise, the attempt must be ceased and documented.
Question 4: When documenting skid marks at an accident scene, which measurement approach provides the most forensically useful data?
- Estimate length visually and record the range
- Measure each mark individually from start to end and record GPS coordinates (Correct answer)
- Photograph only the darkest portion of the skid
- Record total combined length of all marks as a single figure
Correct answer: Measure each mark individually from start to end and record GPS coordinates
Each skid mark must be measured individually with precise start/end points and geolocated to support speed and braking analysis.
Question 5: Under the Motor Carrier Safety Improvement Act, an 'unsatisfactory' safety rating following a pattern of accidents can result in which action?
- Mandatory enrollment in a defensive driving course
- Prohibition from operating in interstate commerce (Correct answer)
- Temporary suspension of CDL for all company drivers
- Reduction in cargo weight limits for 90 days
Correct answer: Prohibition from operating in interstate commerce
Carriers rated 'Unsatisfactory' by FMCSA are prohibited from operating in interstate commerce until corrective action is verified.
Question 6: A truck driver's hours-of-service logbook shows the driver was on duty for 14 consecutive hours before the accident. What regulation is potentially violated?
- 49 CFR 393.9 — lamp requirements
- 49 CFR 395.3 — maximum on-duty time for property-carrying drivers (Correct answer)
- 49 CFR 383.110 — CDL knowledge test standards
- 49 CFR 396.9 — inspection of vehicles in operation
Correct answer: 49 CFR 395.3 — maximum on-duty time for property-carrying drivers
49 CFR 395.3 limits property-carrying drivers to 14 consecutive on-duty hours, making 14 hours the maximum, but any driving beyond 11 hours within that window is also a violation.
Question 7: Which type of data from a commercial vehicle's event data recorder (EDR/black box) is MOST critical for reconstructing vehicle speed at the time of impact?
- Engine coolant temperature readings
- Pre-crash speed trace and brake application data (Correct answer)
- Fuel consumption logs from the prior week
- Idle time records from the past month
Correct answer: Pre-crash speed trace and brake application data
Pre-crash speed traces and brake application timing from the EDR directly enable engineers to calculate vehicle speed at impact.
DOT Accident Investigation & Reporting 3
When interviewing witnesses at an accident scene, which interviewing technique is most appropriate for a DOT investigator?