Highlighted terminology is explained at the bottom of the page.

When reconstructions are performed it is vitally important that the road geometry is both accurately recorded and its pertinent features displayed. During the pre-collision phase, the approach paths for the collision-involved vehicles and road users are fundamental to the road user actions. It is these actions that are tried and contested in the courts of law.

A scale plan is a two-dimensional drawing of the road geometry at a specific ratio relative to the actual size of the collision site. A scale plan allows for measurements to be taken retrospectively.

There are a number methods to secure and record the road geometry of a collision site, from line and offset to triangulation, electronic distance measurement to 3D laser scanning.

In order to objectively analyse the cases we are instructed on, we only use 3D laser scanning to secure and record all of the road geometry. The other methods record only those elements of the road geometry the investigator deems necessary and are highly subject to errors, both systematic errors and random errors.

3D laser scans allow the accurate determination and subsequent visualisation of any sightlines. This is a vital requirement when providing an objective analysis of the collision sequence and witness evidence.

CollisionExperts has a Permission for Commerical Operations from the Civil Aviation Authority and is permitted to fly Small Unmanned Aerial Systems in congested areas (providing certain restrictions are met). Therefore, we provide UAV aerial imagery to complement the 3D laser scans. A product of UAV aerial imagery is the production of orthomosaic imagery. Orthomosaics are a collection of aerial images that form one geometrically corrected image. Orthomosaics record all road user approach paths and the collision site regardless of how large the encompassing geographical area is.

To provide an objective analysis of a collision or other incident, we strongly advise all our clients to consider 3D laser scanning of a collision site when instructing our consultancy services.

Fees & Lead Times

Our service level agreements for fees and lead times for our scale plan services vary due to the complexity of each case and any additional investigative services required.

This service is part of our all-inclusive investigative reconstruction package.

Please contact us to discuss your requirements.


3D Laser Scanning -  The process of analysing an object or environment to collect data on its shape.

Approach Path – The geometric description of the course over ground of the collision-involved vehicles, objects or persons during the pre-collision phase.

Collision Involved Vehicle – A vehicle directly related to a collision.

Collision Sequence – The chronological sequence of events involving the collision-involved vehicles, objects or persons.

Electronic Distance Measurement The electronic measurement between two points through electromagnetic waves.

Orthomosaic Imagery - Aerial images geometrically corrected such that the scale is uniform.

Pre-Collision Phase - The actions and movements of the collision-involved vehicles, objects or persons prior to the impact phase of the collision.

Random Error - An error caused by unknown and unpredictable changes during measurement.

Road Geometry – The geometric design of roads concerned with the positioning of the physical elements of it according to standards and constraints.

Road Users – Persons on the road including drivers, vehicle riders, pedestrians or passengers.

Sightline – A visual axis for a normally unobstructed line of sight between an observer and a subject of interest.

Systematic Error - An error that under the same conditions will always be of the same magnitude and polarity.

Triangulation - The tracing and measurement of a series or network of triangles in order to determine the distances and relative positions of points spread over an area.


our Services

All Inclusive Service Collision Accident

All-Inclusive Investigation

Collision Reconstruction Collision Accident

Investigative Reconstructions
Desktop Analysis Collision Accident

Desktop Analysis
Claim Validation

Claim Validations
Vehicle Examinations Collision Accident

Vehicle Examinations
Laser Scanning Collision Accident

3D Laser Scanning
Forensic Animations Collision Accident

Forensic Animations
CCTV Digital Video Analysis Collision Accident

Digital Video Analysis
Collision Site Analysis Collision Accident

Collision Site Analysis
UAV Collision Accident

UAV Aerial Imagery
Collision Accident Computer Simulations

Computer Simulations
Collision Accident Vehicle Forensics Infortainment

Vehicle Forensics
Collision Accident Crash Data Analysis

Crash Data Analysis
Collision Accident Light Bulb Analysis

Lamp Analysis
Collision Accident Seat Belts

Seat Belt Examinations
Incident Analysis

Incident Analysis
Collision Accident Photography

Site Photography
Collision Accident Scale Plan

Scale Plans
Collision Accident Report Validation

Report Confirmations