Preserve the vehicles and occupant space before repair erases the force path.

Obtain scene measurements, final rest, marks, debris, fluid, damage, road geometry, grade, surface, weather, lighting, signs, signals, barriers, and video. Identify each impact and post-impact event, including rollover, secondary collision, fire, water entry, or fall from a vehicle. Witnesses may describe speed or movement, but reconstruction should use reliable physical and electronic inputs and state uncertainty.

Preserve all involved vehicles before repair, salvage, sale, or destruction. Document exterior damage, crush, intrusion, roof, doors, glazing, seat, seatback, head restraint, belt webbing and anchor, airbag and module, steering, pedals, occupant contacts, cargo, child restraint, motorcycle helmet or gear, and any adaptive equipment. Record post-crash towing, cutting, battery disconnection, rescue, storage, and weather exposure that may alter evidence.

Identify electronic sources by make, model, year, system, and event. Event data may record seconds around a qualifying event, not a full trip, and field availability varies. Telematics, dash video, driver assistance, infotainment, phones, commercial systems, and roadway cameras have different owners and retention. Preserve native downloads, tool and software versions, reports, time bases, and validation against physical evidence.

Record seating position, posture, seat and head-restraint setting, belt use and geometry, airbag deployment, pre-impact maneuver, body orientation, occupant size, objects in the compartment, and each impact. For motorcycles, pedestrians, cyclists, and ejected occupants, map contact surfaces, projection, ground contact, gear, and secondary impacts. Do not assume a low visible repair estimate means low occupant loading or that major crush proves a particular spinal diagnosis.

Coordinate reconstruction, biomechanics, radiology, spine, neurology, and rehabilitation opinions as needed. The engineer can analyze collision and component performance. The biomechanical expert can address motion and loading within qualifications. Medical specialists diagnose cord injury, interpret anatomy, perform a differential, and address prognosis. Each should disclose disputed inputs, sensitivity, and whether another expert supplied a key premise.

Follow symptoms and examinations from the scene through surgery and rehabilitation. Address any delay, evolving weakness, swelling, compression, or later diagnosis with medical evidence. Prior degeneration or spine treatment should be included. The question may involve new injury, aggravation, or both. Rescue and treatment issues should not be criticized through hindsight without a supported standard and causation opinion.

Driver and vehicle analysis may include speed, lookout, distraction, impairment, following, lanes, turns, signals, fatigue, maintenance, loading, and employer or carrier conduct. Commercial rules apply only after verifying definitions and scope. Regulatory records may inform facts but do not supply a universal civil standard. Personal, employer, carrier, owner, rental, and platform relationships require documents.

Crashworthiness asks whether a defective vehicle, restraint, seat, roof, door, airbag, or component enhanced injury beyond the collision. Preserve design and manufacturing information, exact component condition, recalls and complaints as leads, alterations, repairs, maintenance, fit, warnings, and expert testing. Driver fault does not resolve or eliminate a supported enhancement claim.

Roadway theories require exact location, boundary, owner, design, maintenance, work zone, contractor, notice, control devices, barriers, surface, sight line, and causation. State, city, county, turnpike, Tribal, federal, or private parties may control different assets. Review Governmental Tort Claims Act procedure, immunity or exemptions, discretion or design, the proper court or tribunal, and notice before alleging claims.

Identify drivers, owners, employers, carriers, brokers where legally supported, shippers, maintenance providers, rental or leasing entities, platforms, product makers, roadway parties, contractors, and umbrella insurers. Confirm relationships and conduct rather than listing every distribution-chain participant. Federal preemption, the Graves Amendment, workers' compensation, sovereign immunity, and other defenses may require review.

Collect issued liability, commercial, personal, umbrella, excess, uninsured or underinsured motorist, medical-payments, workers' compensation, health, disability, and other policies. Verify insured status, vehicle, driver, business use, exclusions, endorsements, priority, notice, cooperation, reservation, and limits. Marketing or certificates are not coverage contracts. Track liens and subrogation early.

Connect coverage to treatment, rehabilitation, equipment, assistance, home and vehicle needs, work loss, earning capacity, household impact, pain, and supported damages. Life-care plans need medical support and transparent costs. Allocation, benefits, liens, minor or incapacity procedure, and court approval may need specialists.