A sketch is not a crash report: why traffic incidents need a reviewed case file

In many municipalities, a crash report is judged by what it looks like: whether the sketch is clean, whether the photos are legible, whether the document was printed with a stamp and a signature. But an expert crash report does not become reliable because of its presentation. It becomes reliable because of how it was built.

Within a few hours, a traffic incident produces decisions that depend on that report. The parties, the insurer, the civic court or the Public Prosecutor's Office use it. The victim has a right to information about their case. And months later, that same record feeds official statistics and the municipality's road planning.

If the report is drafted on paper, completed on a different computer, corrected by text message and reprinted every time someone spots an error, the institution does not have a report. It has versions. And when there are versions, no one can say with certainty which one is correct, who changed it or why.

Why the crash report matters more than it seems

Traffic incidents are among the most frequent events a public safety and traffic agency handles. They are also among those with the most consequences outside the agency itself.

Mexico's General Law on Mobility and Road Safety, published in the Official Gazette of the Federation in May 2022, defines a traffic crash as any event on a public road involving at least one vehicle that causes death, injury or property damage, and that can be prevented. That last part is central: the law starts from the premise that crashes are preventable, and prevention depends on knowing precisely where, how and to whom they happen.

That is why Article 29 of the same law requires mobility and road safety databases to include crash information with data that make it possible, at a minimum, to geolocate the site, identify the type of vehicle involved and record whether there were injured people and fatalities, by type of road user and their sociodemographic characteristics. None of that data can be reconstructed with quality afterward. It is either captured well in the moment or it is lost.

Article 23 adds another layer: in any administrative, criminal or civil proceeding arising from a traffic crash, victims have the right to receive information so they can make informed decisions and to have their privacy respected. A report that circulates as copies, phone photos and loose files will struggle to meet both obligations at once.

From the local report to national statistics

There is a methodological fact many decision makers overlook. INEGI's statistics on Land Traffic Accidents in Urban and Suburban Areas (ATUS) are not collected through surveys. The unit of observation is the accidents recorded by state or municipal Public Safety and Traffic agencies, and the collection method is the use of administrative records.

In other words, the national figure for urban crashes is the sum of what each municipality documented. INEGI's methodological summary describes how the record begins with the reports filed by the traffic officer, which are then captured and delivered through a questionnaire, through INEGI's own capture system or through databases supplied by the reporting sources. State coordination offices check for omissions, verify consistency and, when they find recurring gaps or errors, ask the source to confirm or correct its figures.

If the municipal report is weak, the national statistic is weak. If the crash location was left in free text, if the vehicle type was captured inconsistently or if the injured were not recorded as a field, no later process can invent that data with certainty. The quality of the country's road policy starts on the expert's tablet or notebook.

Where the report breaks down in daily operations

The failure appears after the crash, when someone needs the report and discovers they cannot trust it.

On-site capture and the final version do not match

The expert arrives, takes photos with a phone, writes plates in a notebook and draws a sketch by hand. Hours later, at the office, everything is transcribed into a form. In that step, details are lost, plates are corrected from memory and the vehicles in the sketch are rearranged. The final document looks better than the notebook, but it is no longer exactly what was observed at the scene.

Review happens outside the record

Many agencies do have a supervisor who reviews reports. The problem is how they do it. If the review happens on a marked-up printout, in a message or in a hallway conversation, the institution does not keep what was observed, what was corrected or who approved it. When a party challenges the report, the agency can only show the final version, not the process that produced it.

The approved report keeps changing

This is the most sensitive point. If the final file remains editable after it has been delivered to the parties, any later correction creates two documents with the same number and different content. For an insurer, a court or a victim, that difference is enough to doubt the whole report.

The injured and witnesses live in other files

Injured people, witnesses and medical care data are often recorded in separate lists or in notes on the incident report. That complicates exactly the data the law asks to cross-reference: injured people and victims by type of road user. If they are not in the same record as the crash, statistics count them incorrectly or not at all.

Statistics are compiled by hand at the end of the month

When each report is an isolated document, the monthly report becomes a transcription task. Someone opens reports one by one and fills in a spreadsheet to deliver to INEGI's state coordination office or to the mobility department. Every transcription is a chance for error, and every error comes back as a correction request.

What distinguishes a reliable crash report

The difference lies in the record's life cycle, not in the PDF.

Four principles support that shift.

1. Capture where the incident happens

The best moment to record plates, location, vehicles and people is at the scene. That requires tools that work in the field, even on municipal streets or roads with intermittent signal. If capture depends on connectivity, the expert goes back to the notebook and the problem returns.

2. Structure what will be counted later

The General Law on Mobility and Road Safety already states what data a crash database must contain. That data should be fields, not paragraphs: georeferenced location, vehicle type, injured people, fatalities, type of road user. The expert's narrative is still necessary, but it cannot be the only place where the information that will later be aggregated lives.

3. Review inside the workflow, not around it

A good review leaves a trace. The supervisor approves or returns the report with comments, and the expert corrects it on the same record. That way the institution can later show that the report went through control, who approved it and what changed between the first capture and the final version.

4. Lock what is approved

Once approved, the report should not change silently. If new information emerges later, the institution can document it as an additional action, but the original report stays as it was approved. That rule allows the parties, the insurer and the court to trust that everyone receives the same document.

Why this is also a road safety decision

The crash report is often seen as a formality between private parties. But the World Health Organization notes that approximately 1.16 million people die each year in road traffic crashes worldwide, that 92% of those deaths occur in low- and middle-income countries, and that crashes cost most countries around 3% of their gross domestic product. The United Nations target is to halve road traffic deaths and injuries by 2030.

That target depends on a municipality being able to see precisely which intersections concentrate crashes with injuries, at what times, with what types of vehicles and with which road users involved. That information comes from hundreds of crash reports captured with the same structure, reviewed with the same criteria and available for analysis without transcription.

How Tribuna addresses it

Tribuna includes a forensic experts module designed for this full cycle. The expert records the crash from a tablet and completes it on the web on the same report: vehicles, injured people, witnesses, photos and sketch. The sketch is created in a built-in editor with a print frame, so the drawing is part of the report and not a separate file.

Review happens inside the platform. The supervisor approves the report or returns it with comments for correction, and the approved report is locked. The official document is generated as an expert report in PDF from the same record, and accident statistics can be exported to Excel without recapturing the data.

Field work does not depend on signal. The tablet app stores everything on the device and syncs as soon as the connection returns, with a sync center that shows the status of each record. From the same tablet, the expert can search vehicles by plate or VIN, including by scanning the plate, and dictate the narrative so it is transcribed on the device.

Because the report lives in the same database as the rest of the operation, it also connects to everything else. A plate search in Tribuna returns associated incidents, violations and relevant operational context. Every read and every change is logged, with a complete timeline per case file, and role-based permissions define who can view or modify each report. The intelligence map adds layers for incidents, concentration by hour and day versus night comparisons so road planning starts from data.

It is the same logic we apply to detention: a record that moves between areas without being rewritten, with review and audit inside the workflow. We explain it in detail in A booking log is not detention management.

Questions for evaluating a forensic solution

Before buying or renewing a tool for forensic services and traffic, it is worth asking:

• Can the expert capture on site even without signal?
• Are the sketch, vehicles, injured people and witnesses part of the same report?
• Is the supervisor's review recorded, with approval or return?
• Is the approved report locked, or can it still be edited?
• Is the data required by Article 29 of the General Law on Mobility and Road Safety captured as structured fields?
• Do the monthly statistics come from the same data, without transcription?
• Is there a log of who consulted and who modified each report?

If several answers are no, the problem is not the report's format but the process that produces it.

The institutional lesson

A well-drawn sketch does not guarantee a reliable report. What guarantees it is a record that is born at the scene, completed without transcription, reviewed inside the workflow and locked once approved.

That shift protects the parties, reduces correction requests from INEGI and gives the municipality useful information to prevent crashes instead of only counting them.

If your institution is reviewing how it runs forensic services and traffic, explore the forensic experts module in Tribuna, see how Agora organizes the municipality's citizen services, or request a demo.

Sources

• Chamber of Deputies of Mexico, Ley General de Movilidad y Seguridad Vial, current text, last amended DOF 2023-12-29
• INEGI, Síntesis metodológica de la estadística de accidentes de tránsito terrestre en zonas urbanas y suburbanas
• INEGI, Estadística de Accidentes de Tránsito Terrestre en Zonas Urbanas y Suburbanas, 2024, National Metadata Network
• World Health Organization, Road traffic injuries, fact sheet