Visibility is one of the most important factors for drivers, particularly for those of large vehicles such as HGVs and vans, which have the highest rate of other road user deaths per mile travelled[1]. The direct vision of a driver is influenced by factors such as the location, size and shape of the windows, and any obstructions such as sat navs, whilst indirect vision is influenced by factors such as mirror shape and position.
When reviewing road traffic collisions, it is critical to determine what a driver was able to see – especially in accidents involving a vulnerable road user (VRU). TRL’s visibility assessment tool or ‘eyeball’ allows our experts to recreate a driver’s eye position, trace their direct/indirect vision and identify any objects that may cause obstruction (such as the steering wheel, dashboard or windscreen-mounted devices). Based on this information, the areas of available vision can be marked out at ground level. As an example, the area of indirect visibility from a Class VI centrally mounted mirror is shown in the image below.
The vehicle, ground markers and eyeball position are all recorded using a 3D laser scanner, from which a detailed 3D model can be created. By combining this modelled driver vision with other incident information such as CCTV analysis, we can accurately reposition vehicles and VRUs and reliably conclude what was available to be seen prior to a collision. Based on this, it can be determined whether the incident could have been avoided, which is particularly valuable when presenting cases to the Court.
Our experts within the TRL Investigations Team have a high level of technical competence and experience in this area. The analyses and modelling techniques developed at TRL have been accepted by the Courts and have proven to be a useful tool to demonstrate the issues clearly, particularly for those who do not have experience driving these vehicles.
By performing complete reconstructions of an incident alongside 3D modelling and laser scanning, we are at the forefront of the latest visibility technologies, and we have played a key role in the move from 2D to 3D modelling over the years. In addition to our legal work, we continue to work closely with policymakers on regulation such as the Direct Vision Standard.
Our in-depth approach to examining visibility is applicable to a wide range of vehicles, from LGVs and plant vehicles to buses and cars. We present the facts in an understandable way, whether that be as a detailed series of images, within an expert report or as a moving reconstruction of a scene using 3D modelling and visualisations. If you would like to find out more about the importance of visibility and how we can assist, get in touch with us at: investigations@trl.co.uk
[1] https://www.pacts.org.uk/wp-content/uploads/PACTS-What-kills-most-on-the-roads-Report-15.0.pdf