93093 - Traffic Accident Reconstruction M

Learning outcomes

The aim of the course is to teach the student the fundamental principles of Forensic Engineering. At the end of the course the student is able to manage advanced techniques for the technical and kinematic reconstruction of road accidents and, consequently, for the continuous improvement of traffic safety.

He is able to:

1. evaluate how the different types of set-up and the active and passive safety devices affect the dynamic behavior of a vehicle;
2. conduct inspections and surveys on the site of the accident and on the vehicles involved;
3. identify the causes in humans, infrastructure and vehicles;- develop motion calculations;
4. independently draw up a written paper correctly.

Course contents

Prerequisites

Basic knowledge of physics, rational mechanics, vector algebra and numerical calculation is required. Elementary knowledge of statistical error analysis and spreadsheets is useful. No previous specialist knowledge of road accident reconstruction is required.

The course presents the principles and methods of forensic engineering applied to the technical reconstruction of road traffic accidents.

The course focuses on the entire reconstruction process: acquisition and assessment of evidence, formulation of hypotheses, application of physical models, uncertainty analysis, assessment of accident avoidability and communication of results.

Topics covered

• Forensic engineering and reconstruction methodology

Purposes and limitations of technical accident reconstruction. The technical question and the professional assignment. Judicial and out-of-court activities. Roles of the court-appointed technical expert, the party-appointed technical expert and the expert witness. Distinction between data, assumptions, hypotheses, technical findings and legal assessments. Responsibilities, independence and methodological correctness of the technical expert.

• Sources of evidence and data quality

Reports and surveys produced by investigating authorities, photographs, videos, witness statements, medical records and technical documentation. Traceability of sources, data preservation, chain of custody, reliability and mutual compatibility of evidence. Management of missing or contradictory data.

• Accident-scene survey and infrastructure analysis

Final positions, tyre marks, gouge marks, debris, fluids and other physical evidence. Road geometry in plan and elevation, gradients, superelevation, intersections, road surface, road signs and markings, road restraint systems, lighting and visibility.

Traditional measurement methods, photogrammetry, laser scanners, LiDAR and data acquisition from ground-based or aerial images. Survey uncertainty and tolerances.

• Vehicle inspection and electronic data acquisition

Vehicle identification, damage compatibility, deformation measurement, tyres, steering and braking systems, occupant restraint systems and safety devices.

Data obtained, when available, from Event Data Recorders, electronic control units, tachographs, telematics systems, video devices and driver-assistance systems. Limitations, synchronisation and validation of digital data. Specific features of electrified vehicles relevant to inspection and analysis.

• Mechanics applied to accident reconstruction

Review of the kinematics and dynamics of planar motion. Tyre-road interaction, grip, rolling resistance and aerodynamic drag.

Acceleration, braking, road gradient, cornering, yaw, loss of control and rollover.

Vehicle set-up and vehicle dynamics are addressed only insofar as they are relevant to accident reconstruction and the interpretation of evidence.

• Pre-impact phase analysis

Time-distance reconstructions, relative positions, speeds, accelerations and trajectories. Analysis of videos and photographic sequences. Sight and stopping distances.

Perception, hazard recognition, decision-making and response. Visibility, conspicuity, attention and cognitive workload. Braking, steering and avoidance manoeuvres.

• Impact mechanics

Impulse and momentum, energy balance, coefficient of restitution, relative impact velocity, change in velocity and energy dissipation.

Assessment of the energy associated with permanent deformation. Central, eccentric and oblique impacts. Vehicle translation and rotation. Limitations of point-mass and planar models.

• Post-impact phase analysis

Sliding, rotation, rollover and projection motion. Determination of speeds from trajectories, physical marks and final positions.

Backward and forward reconstruction methods. Consistency checks between the different phases of the accident.

• Main types of road traffic accidents

Frontal, rear-end, side and oblique collisions. Impacts against fixed obstacles. Multiple-vehicle accidents. Loss-of-control accidents and rollovers.

Accidents involving heavy vehicles. Accidents involving motorcycles, cyclists, pedestrians and other vulnerable road users, including micromobility devices.

Introduction to the biomechanical compatibility of injuries and cooperation with forensic medical experts.

• Safety systems and driver-assistance technologies

Anti-lock braking systems, electronic stability control, automatic emergency braking systems and other advanced driver-assistance systems.

Occupant restraint systems, airbags, controlled deformation and crash testing. Reconstruction of whether and how such systems intervened, distinguishing their theoretical performance from what can be demonstrated in the specific case.

• Technical causation, avoidability and uncertainty analysis

Formulation and comparison of alternative hypotheses. Technical causal and contributing factors relating to the road user, the vehicle and the infrastructure.

Identification of technically feasible alternative conduct and manoeuvres. Sensitivity analysis, propagation of uncertainty, result ranges, robustness of conclusions and limitations on the applicability of models.

Validation of analytical and simulation results.

• Technical report and communication of results

Structure of the report, description of the evidence, declaration of assumptions, presentation of calculations, use of images and diagrams, citation of sources and reproducibility of the analysis.

Distinction between results, interpretations and conclusions. Oral presentation and technical discussion of the report.

 

Readings/Bibliography

Materials required for exam preparation

Lecture notes, presentations, worked exercises, formula sheets, datasets, technical documentation and case studies published by the lecturer on the OneDrive shared directory.

Recommended readings

• G. Centamore, D. Leanza, Ricostruzione incidenti stradali: matematica e fisica, EGAF, fifth edition.
• D. E. Struble, J. D. Struble, Automotive Accident Reconstruction: Practices and Principles, second edition, CRC Press.
• A. Pietrini, Ricostruzione incidenti stradali. Dall’approccio metodologico al dibattimento in Tribunale, EGAF, second edition.

Further readings

• N. A. Rose, W. T. C. Neale, Motorcycle Accident Reconstruction, SAE International.
• A. Orlandi, Meccanica dei trasporti, limited to the topics indicated by the lecturer.
• G. Genta, Meccanica dell’autoveicolo, limited to the topics indicated by the lecturer.
• Scientific papers, test reports, technical standards and supplementary documents indicated during the course.

Teaching methods

The course combines lectures and interactive classes, guided solution of numerical problems, discussion of case studies, exercises using spreadsheets and image and video analysis tools, surveying and photogrammetry activities, individual preparation of a technical case study, and seminars involving professionals, technical experts and practitioners in the field.

The exercises are organised to progressively connect the available evidence with physical models, calculations, uncertainty analysis and the formulation of conclusions.

Technical visits may be organised at companies, laboratories, institutions or other organisations operating in the field. These activities depend on the availability of the host organisations and are not a requirement for passing the examination. Organisational information will be published on Virtuale.

Considering the types of activities and teaching methods adopted, attendance at activities carried out in places involving specific risks requires the completion of modules 1 and 2 in e-learning mode and participation in Module 3 on specific health and safety training in study environments.

Information concerning the dates and attendance procedures for Module 3 is available in the relevant section of the Degree Programme website.

Assessment methods

The assessment consists of:

• an individual written examination;
• an individual or group technical report;
• an oral examination.

Individual written examination

The written examination accounts for 40% of the final grade.

The examination lasts 120 minutes and includes one or more numerical problems and interpretation questions relating to the pre-impact, impact or post-impact phases.

The examination assesses the student’s ability to select and correctly apply appropriate models, state the assumptions adopted, use consistent units of measurement, interpret the results and recognise their limitations.

An intermediate written examination equivalent to the examination administered during the regular examination sessions may be organised during the course. The result remains valid until the final examination session of the academic year and may be rejected by the student.

A non-programmable calculator and any formula sheet provided by the lecturer may be used during the examination.

Books, notes, internet-connected devices and any other materials not expressly authorised are not permitted.

Students who do not take the written examination will be required to complete a written exercise during the oral examination.

Individual or group technical report

The technical report accounts for 30% of the final grade.

The technical report concerns either an individual meta-analysis or a group experimental activity, both of which must be agreed upon with the lecturer.

The meta-analysis must include the definition of the research question, the criteria used to search for and select sources, a critical comparison of the studies and their results, any quantitative analysis of the data, a discussion of the limitations and the conclusions.

The report on the experimental activity must include the objective of the test, the method adopted, the instruments used, the data acquired, the calculations and analyses performed, the assessment of uncertainties, the discussion of the results and the conclusions.

For group activities, the members of the group and the contribution made by each member must be specified. All participants must be familiar with and able to discuss the entire project. Assessment remains individual.

The report and any presentation slides must be sent to the lecturer by email at least two working days before the oral examination.

Oral examination

The oral examination accounts for 30% of the final grade.

The oral examination includes a presentation of the report lasting no more than 10 minutes, a critical discussion of the methodological choices, data and results, one or more questions on the topics covered during the course and, where appropriate, the impromptu formulation of a short accident-reconstruction problem.

The oral examination assesses understanding of the underlying principles, the ability to connect the different phases of the analysis, independent judgement and the correct use of technical terminology.

Determination of the final grade

A minimum grade of 18/30 must be obtained in each of the three assessment components.

The final grade is calculated according to the following weighted average:

• written examination: 40%;
• technical report: 30%;
• oral examination: 30%.

Grades are awarded according to the following criteria:

• 18-20: essential knowledge, application of methods to the simplest cases, limited autonomy and the presence of non-substantial inaccuracies;
• 21-24: adequate preparation, correct solution of standard cases and appropriate technical language;
• 25-27: solid preparation, good autonomy in selecting methods and correct critical interpretation of results;
• 28-30: comprehensive preparation, ability to integrate evidence and models, informed analysis of uncertainty and rigorous technical communication;
• 30 with honours: excellent preparation, full autonomy, particularly rigorous methodology and the ability to critically compare alternative hypotheses and results.

Students must register for the examination through AlmaEsami within the prescribed deadlines.

USE OF ARTIFICIAL INTELLIGENCE

The use of generative artificial intelligence systems is prohibited during written and oral examinations held in a controlled environment.

For the technical report, limited, declared and non-substantial use of artificial intelligence is permitted for activities such as searching for sources, language revision, rephrasing or the preliminary organisation of content.

Artificial intelligence may not be entrusted with the selection of models, the substantial performance of calculations, the interpretation of evidence, the formulation of conclusions or the generation of unverified bibliographic sources.

Any use of artificial intelligence must be declared in a brief note attached to the report.

Personal, judicial, confidential or non-public case data must not be uploaded to external services.

The oral discussion may be used to verify the student’s full understanding and authorship of the work.

STUDENTS WITH SPECIFIC LEARNING DISABILITIES OR OTHER DISABILITIES

Students with temporary or permanent disabilities or specific learning disabilities are invited to contact the relevant University office in good time.

The office will propose any appropriate accommodations to the students concerned. Such accommodations must, however, be submitted to the lecturer for approval at least 15 days in advance. The lecturer will assess their suitability, also in relation to the learning outcomes of the course.

Teaching tools

In order to improve preparation, support students in achieving the best possible examination performance and make lectures accessible to those who may occasionally be unable to attend, lectures are recorded and made available upon request.

The following materials are made available as required:

• presentations and lecture notes;
• formula sheets and calculation examples;
• spreadsheets and datasets;
• photographs, videos and three-dimensional models;
• examples of technical reports;
• regulatory and technical documentation;
• instructions for exercises;
• guides to the use of the software employed during the course.

Software applications for spreadsheets, technical drawing, photogrammetry, video analysis and data visualisation may be used.

Where compatible with their nature, materials will be provided in accessible and editable formats.

Office hours

See the website of Alfonso Micucci