At highway speed, seconds and feet must be measured rather than described.

The scene record should fix direction, lane count, median and shoulder, grade, curvature, construction, lighting, pavement, weather, traffic density, queue formation, sight distance, and the first observable hazard. A driver can be within a posted limit yet moving too fast for stopped traffic, visibility, weather, or a work zone. A driver can also exceed a posted limit without that excess causing the particular collision. The reconstruction must connect speed to available perception, braking, steering, and impact avoidance.

Physical evidence may include tire marks, gouges, debris, fluid, barrier contact, final positions, crush, airbag deployment, restraint evidence, rollover marks, and roadway scars. Police measurements and diagrams should be checked against photographs, scans, survey data, and vehicle dimensions. Post-impact travel cannot be treated as pre-impact speed without an accepted method and inputs. Multiple impacts, braking systems, grades, and surface conditions can change the calculation.

Electronic sources can include event data, engine or telematics information, navigation, driver-assistance alerts, phone location, toll transactions, camera timestamps, and another vehicle's data. Each has a sampling rate, clock, trigger, field definition, accuracy, and ownership question. A recorded value may represent a wheel, selected field, rounded output, or different moment than expected. The source should be preserved in native form and interpreted by a qualified person when necessary.

Public roadway sources can include construction plans, traffic-control plans, daily work reports, lane-closure records, incident logs, maintenance work, guardrail history, sign and pavement-marking records, weather treatment, traffic counts, and communications with contractors. The roadway segment and jurisdiction must be established. The Oklahoma Department of Transportation expressly limits its records process to its information and directs city or county requests elsewhere, underscoring why a generic highway request is inadequate.

Traffic and camera sources may include live-condition systems, message signs, traffic sensors, incident-management feeds, patrol video, wrecker dispatch, toll data, and commercial fleet cameras. A live public view does not establish archival recording. The system operator should confirm whether the device recorded, the field of view, event date, clock, retention, and export. News or social-media clips should be preserved with source and metadata rather than downloaded without attribution.

Private parties may hold vehicle inspections, downloads, repair estimates, photographs, dash cameras, telematics, cargo or passenger information, driver schedules, and insurance examinations. A commercial vehicle adds operator, employer, carrier, and regulatory questions, but passenger-car rules should not be mixed with commercial ones. Preservation should cover the involved vehicle before salvage or repair while accommodating ownership, inspection, safety, and storage needs.

Driver conduct may involve speed, following, lane change, fatigue, distraction, impairment, passing, weather, or queue response. Match traffic law and ordinary care to the maneuver. Evaluate comparative fault with the same precision, not from an enforcement account or severe outcome.

A roadway theory needs a defined control, work-zone, visibility, pavement, drainage, barrier, shoulder, or queue condition. Identify the public entity and contractor; review duty, design or discretion, maintenance, notice, exemptions, Governmental Tort Claims Act procedure, and causation. A dangerous-condition label does not establish waiver or defeat immunity.

A product theory may concern tires, brakes, steering, restraints, airbags, structure, guardrail interaction, or crashworthiness. Preserve the vehicle and history before destructive testing. Recalls, warnings, or codes require proof of model fit, remedy, condition, alternative causes, and injury enhancement. Separate product and driving causation.

Emergency response, extrication, restraint evidence, vehicle intrusion, occupant position, imaging, surgery, intensive care, rehabilitation, cognitive or psychological care, work loss, and family caregiving should be organized chronologically. Future-care and life-care opinions require medical foundation and realistic assumptions. Preexisting conditions should be addressed directly so the analysis distinguishes prior function, aggravation, new injury, and unrelated later events.

Coverage may involve vehicle owners and drivers, employer or commercial, umbrella, uninsured or underinsured motorist, product, or contractor policies. Multi-vehicle events may create conflicting tenders. Review limits, insureds, permissive use, employment scope, exclusions, priority, exhaustion, and reservations; visible damage does not identify every source.

A fatal or life-altering event also raises estate, beneficiary, guardianship, lien, government-benefit, and settlement-approval questions. Early payment pressure should not force a release before responsible parties, policies, and future needs are understood. At the same time, preservation costs and vehicle storage need practical decisions. Written inspection agreements can protect evidence while allowing safe disposition after the relevant parties have a fair opportunity to inspect.