In many developed countries the number of fatalities is falling even as traffic volumes grow, due in part to studying of the cause and effect of traffic accidents, which in turn has had an influence on the creation of safety systems now routinely fitted to passenger vehicles. This experience should aid those countries only now becoming heavily motorised.
There has been something of a revolution in the effectiveness of Collision Investigation Units in recent years, thanks to the uptake of superior apparatus – commonly employed by automotive manufacturers in vehicle testing, development, and validation - for use in accident reconstruction and simulation. Having been at the forefront of the vehicle testing market for several years, VBOX data logging equipment is a perfect fit given that it is portable, versatile, and user-friendly.
Accident reconstruction and simulation will often call for accurate measurement of speed and distance, so applying automotive testing methods to achieve this makes a lot of sense. More often than not, the evidence gathered from recreating the conditions in which a collision occurred needs to be presented in a court of law, so data presented in as straightforward a manner as possible is vital – video is the perfect solution. The Video VBOX is used by Collision Investigation Units to impart information that otherwise might be difficult and complex to convey.
- Measure distance to high accuracy in collision reconstruction
- Calculate reaction time/time to collision
- Integrated video allows for simple presentation of key facts
- Test of vehicles for substandard maintenance, such as low tyre pressures
- Verification of investigation techniques
Measured / Calculated Parameters
Depending on the VBOX equipment in use, the following parameters can be measured:
- Radius of Turn
Depending on the VBOX equipment in use, the following parameters can be calculated:
- Coefficient of friction
- Reaction time
- Time to collision
VBOX equipment used by Collision Investigation Units varies. The 10Hz VBOX Mini, which allows for simple speed and distance measurements in a small form-factor with built in screen, is used by those that require basic verification of their reconstruction procedures, and to configure vehicles to ascertain their performance capabilities.
The Video VBOX is often put to very effective use because it allows CIUs to not only measure speed and distance at an accident simulation, but also to then present it in a simple manner to back up data being presented in court. The overlaid graphical capability of a Video VBOX means that key facts of a case can be conveyed far more easily than through the sole presentation of data in diagrammatical form.
The VBOX 3i and VBOX 3i Dual Antenna offer extremely high speed, distance, and time measurement resolution, as well as CAN Bus capability often put to good effect when verifying a vehicle's onboard systems during collision reconstruction.
100Hz GPS and CAN sampling, commonly used in vehicle dynamics testing and development, means that an accident investigation team has access to the same level of precision that can ensure their procedures and results are beyond questioning.
Collision Investigation Unit, Cumbria
When assessing an accident, a Video VBOX Pro will be used to measure a distance to impact, determining if there was sufficient space – and therefore time – to avoid a collision. Marks on the road are highlighted and the path of the vehicle is filmed, with an accurate distance measurement being displayed within the overlaid graphics. This allows for the presentation of the evidence to be starkly clear to those who assess how the accident occurred and to apportion responsibility for it.
The simplicity with which complex data can be displayed is the Video VBOX’s main strength and makes the presentation of such information much more straightforward than traditional methods.
Thames Valley Police
The VBOX Micro, connected to a GPS combiner and two antennas – to ensure continuity of satellite lock when the bike falls onto its side – is packed into the seat unit with a battery pack. The bike is then towed up to a set speed and ‘dropped’ so that it falls and skids along the runway. The test is filmed by a rear-facing VBOX HD and graphics are added in post processing.
The investigators then validate their existing crash forensic methods against evidence they have collected: whilst it seems very obvious what will happen to a motorcycle when its rider loses control, being able to safely replicate this has been hitherto impossible. Although these tests are in their infancy, the Thames Valley CIU are building a database of crash types that aids them when examining real-world incidents, and helps them to further understand the dynamics of motorcycles involved in accidents.
ARC CSI and Crash Investigation in the USA
ARC CSI, held annually in Las Vegas, is a crash conference. Around eight to ten crashes are conducted with a variety of equipment installed in the test mules in a range of accidents: cars into cars, buses into cars, vehicles into concrete blocks - either headlong or offset, and so on. With each test being conducted with full instrumentation onboard, it allows attendees to examine the data and make comparisons with their own collision reconstruction practices.
Typically a crash reconstruction is carried out using a VBOX 3i along with a VBOX HD video data logger. GPS and vehicle signals are combined to demonstrate what happens to a vehicle and its occupants in the event of a collision. This combination provides a visceral, powerful way of crash reconstruction.
Bringing data and measurements into the court room in America means that they must comply with the Daubert Challenge (essentially a verification that any evidence presented is scientifically valid, and able to be applied to the case in question) and that any equipment used is industry standard, correctly operated, and verifiably calibrated. VBOX products are recognised as meeting these criteria.
Essex Collision Investigation Unit
The CIU within the Metropolitan Police Force use a VBOX 3i to corroborate their methods in determining the speed of a vehicle captured on CCTV. When an accident has been recorded by surveillance equipment it is used as evidence, with the speed of the vehicles being calculated by measuring the incident area and using the frame rate of the video.
The accident is then simulated using the 100Hz VBOX 3i and a light barrier system placed at the same points from the original video. The light barrier produces a digital trigger signal and the distances involved are measured with high accuracy. The speeds are then corroborated and cannot be challenged during subsequent court proceedings. The Metropolitan CIU now use their VBOX 3i as a standard item of equipment during scene investigations.