Call For A Free Consultation(602) 345-1818Free Case Review
Fighting Suits, Stories, animation and community. Created by Impact Legal.
We're Here To Help 24/7
(602) 345-1818Updated September 14, 2026
Accident reconstruction can help an Arizona car accident claim when physical evidence can answer a disputed question about the collision. It has a cost and limits. Before retaining an expert, identify the question, the available evidence and whether the analysis is likely to assist. This guide explains possible inputs, useful questions and early preservation steps.
Our Phoenix car accident practice can review whether an investigation is appropriate for the facts. A reconstruction does not guarantee a change in fault or a higher settlement.
Accident reconstruction uses relevant measurements, vehicle information and other evidence to analyze speed, position, timing or the sequence of a crash. Qualifications must fit the task. An engineering background, police experience or certification may be relevant, but no title alone proves that an expert can reliably answer every question, particularly a separate medical-causation question.
The NHTSA Special Crash Investigations program describes detailed investigation of selected crashes using scene, vehicle and occupant information. Civil reconstruction likewise may combine several sources. There is no rule that every reconstruction must contain exactly three data streams or that an expert can resolve every missing fact.
That’s it. It’s not magic, and it’s not a substitute for witness testimony or the police investigation. It’s a physics-based check on the story each side is telling.
Scene, vehicle and electronic information can each help. The importance of a missing source depends on the question and what other reliable evidence remains. Explain gaps instead of filling them with unsupported assumptions.
This is what was on the roadway at the time of the crash. Reconstructionists pull it from:
Surveying, photogrammetry or other measurement methods can produce scaled diagrams when the source material supports them. The analyst should document equipment, reference points, scale and limitations. A diagram based only on an unscaled photograph should not be presented as a precise survey.
Roadway conditions, debris and vehicle positions can change quickly. Obtain photographs and measurements when safe and lawful, and identify records made before the scene changed. A later inspection may still provide useful geometry, but distinguish present conditions from what existed at the time of the crash.
The vehicles themselves are physical records of the crash. A reconstructionist inspects:
Damage analysis may support an estimate of collision forces or speed when adequate data and a reliable method exist. It does not produce a unique speed from every photograph. Lighting analysis is equipment-specific; assumptions about filament bulbs may not apply to LED systems. An opinion should explain uncertainty and alternative explanations.
Repair, component replacement or crushing can alter physical evidence. A sale or salvage auction does not automatically erase it, but access and condition may change. Identify the custodian, discuss a timely inspection and address storage costs and deadlines rather than assuming the vehicle will remain available indefinitely.
An event data recorder stores specified technical information around a qualifying event. NHTSA’s EDR overview explains that these devices record vehicle and occupant information for a short period around a crash. Not every vehicle or event supplies the same record, and 49 CFR Part 563 is not a guarantee that a particular car recorded every desired field.
Depending on the system, available information may include:
Technical data can be useful but still requires interpretation. Check the event identity, completeness, time reference, sensor definitions and report limitations. A recorded speed field is not automatically the exact impact speed, and change in velocity is not the same as closing speed.
Use an appropriately trained examiner and a retrieval method supported for the vehicle. Some systems use Bosch CDR tools; others require different equipment or procedures. Retention depends on the module and event, including whether data was locked or overwritten. NHTSA’s 2026 final rule delays expanded pre-crash capture requirements to a phased schedule beginning September 1,2028. Do not assume every vehicle on the road already contains a universal five-second or twenty-second record.
A.R.S. § 28-667 directs an investigating officer or public employee to complete a written report for specified crashes, including injury, death, property damage over $2,000 or a citation. The report may contain:
Distinguish an officer’s firsthand observations from witness statements and conclusions. A civil factfinder is not bound to adopt an officer’s fault assessment. A reconstruction can test relevant physical questions, but an inconsistency with a report does not by itself establish that either source is wrong. Preserve the report and any supplemental materials.
If you don’t yet have your copy, here’s how to get your Phoenix crash report.
When sufficient evidence and a reliable method exist, a qualified reconstructionist may address:
The useful result may be a range of possibilities rather than a single answer. If several sequences fit the evidence, the expert should say so. An opinion that rejects a scenario needs a reliable explanation of why the evidence is inconsistent with it, not simply confidence in one driver’s account.
This is where honest analysis matters. A reconstructionist cannot:
Arizona Rule of Evidence 702 governs expert admissibility. Qualifications, helpfulness, sufficient facts and reliable methods and application matter. The proponent must establish the rule’s requirements more likely than not. An impressive animation or credential does not replace that showing.
Reconstruction is expensive, and cost has to be proportionate to case value. Rather than quoting a fee that can shift with the market, the honest question is whether the potential swing in fault (and the dollar value of that swing) justifies the investment on your specific case.
An expert may be useful where:
A narrower investigation may be sufficient where:
Discuss scope, estimated fees, available evidence and alternatives before authorizing work. Low visible damage alone does not rule out injury, and a serious injury alone does not make every reconstruction worthwhile. The decision should turn on the question the expert can reliably answer.
Under A.R.S. § 12-2505, Arizona generally reduces damages by the claimant’s percentage of fault, with statutory exceptions including intentional, wilful or wanton claimant conduct. An adjuster can propose a settlement allocation, but that proposal is not a judicial finding. A reconstruction may supply relevant facts without dictating the legal result.
For example, a hypothetical 20% fault reduction applied to $100,000 in proved damages leaves $80,000 before other adjustments. That arithmetic explains why a material liability dispute can matter. It does not establish that hiring an expert will shift the allocation or recover the expert’s cost.
Preservation decisions may be urgent even when a full reconstruction decision can wait. Identify evidence at risk and arrange a proportionate response.
A focused preservation letter documents a request to retain relevant material; it does not physically secure it or automatically impose a duty on an unrelated holder. Lips v. Scottsdale Healthcare Corp.,224 Ariz. 266 (2010) explains that a unilateral request does not itself create such a duty. Souza v. Fred Carries Contracts, Inc.,191 Ariz. 247(App.1997) treats evidence-loss remedies according to the circumstances. Seek confirmation and appropriate legal process rather than assuming delivery guarantees preservation.
An Arizona injury lawsuit against a private party generally has a two-year limit after accrual under A.R.S. § 12-542. A public-entity or public-employee claim generally requires a proper notice within 180 days after accrual under A.R.S. § 12-821.01, plus a separate lawsuit within one year after accrual under A.R.S. § 12-821. These are separate requirements, not extra time added to the private-party deadline. Identify the claimant, responsible parties and accrual date early. Minority, disability and other exceptions require individual review. A private contractor does not automatically become a public entity because it works on a public road.
A preservation request does not extend these deadlines. An inspection by a qualified professional may be appropriate before a filing decision, but neither task should be mistaken for completion of the other.
If your crash was recent, these steps make an actual difference:
Arrange early review when relevant evidence may change or disappear. The need and timing depend on the vehicle, records and disputed questions. A limited inspection or preservation step may precede a decision on full reconstruction. There is no universal video or EDR expiration period.
Some fee agreements provide for advancing investigation costs. Ask who pays, when reimbursement is due and what happens if there is no recovery. Do not assume expert fees are included in an attorney-fee percentage or that every proposed expense will be approved.
No. A crash report can provide useful observations and information, but it does not bind a civil factfinder to its fault conclusion. Admissibility and weight depend on the contents and applicable evidence rules. Other reliable evidence can support a different conclusion.
A citation alone does not answer whether technical evidence is needed. Identify the disputed facts and the status of the citation. A traffic allegation is not automatically a conclusive civil finding. An expert may help if a material physical question remains and reliable analysis is possible.
EDR information is technical data recorded around a qualifying event. Fields, duration and availability vary by vehicle and system. A preservation letter alone does not grant access. Retrieval requires lawful authority, appropriate consent or process and a qualified method. Review the actual download limitations before drawing conclusions.
Fees depend on the proposed scope, inspections, data work, analysis and testimony. Request an estimate and explain how expanded work would be authorized. The relevant question is whether the expert can reliably address a material issue at a proportionate cost; no fee amount guarantees a favorable result.
We can review the crash information, available evidence and disputed questions to assess whether reconstruction would help. Bring the report, photographs, vehicle location and any written disposal deadline or coverage decision to the consultation.
Free case review: (602) 345-1818. We answer 24/7. No attorney’s fees unless we recover, with costs and fee terms set out in the written agreement.
By Jared J. Pehrson | Impact Legal Car Accident Attorneys
