Has an insurer rejected your injury claim after a delta-v assessment? Start by identifying exactly what is disputed: the collision calculation, the link with your symptoms, your limitations or the amount of your loss. This article explains how to review the report, organise the evidence and discuss further expert work in a Dutch personal injury claim.
What is delta-v?
Delta-v is the change in a vehicle’s velocity during a collision. It is not the driving speed just before impact, a direct measurement of the force on an individual occupant, or a medical diagnosis. Direction and the way the velocity changes also matter when interpreting the collision.
Simple illustration: if a vehicle slows from 50 km/h to 40 km/h during a collision while continuing in the same direction, the magnitude of that velocity change is 10 km/h. This simplified calculation says nothing by itself about a particular person’s injuries.
A report may describe a relatively small change in velocity. Ask which conclusions the expert actually draws, what assumptions support them and whether a technical conclusion has been presented as a medical conclusion. A single number does not replace assessment of the individual evidence.
How insurers use delta-v
Insurers often engage experts to calculate the delta-v. They then use that calculation to assert that:
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the accident was too minor to cause injury,
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there is no causal link between the accident and the complaints,
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damages do not need to be paid, or only to a limited extent.
For victims, this often feels as if their complaints are being ignored.
First identify the actual reason for rejection
Ask the insurer to specify which part of your claim is disputed and on which documents it relies:
- The technical reconstruction: are the collision data or calculations disputed?
- The relationship with your symptoms and limitations: which medical questions remain unanswered?
- The resulting financial loss: is the disagreement about lost income, care costs or another loss item?
These questions require different evidence. A correction to the collision calculation does not automatically prove every claimed limitation or loss. Equally, a calculation alone does not replace a medical assessment. Review the technical report alongside the relevant medical and financial evidence.
What can you do in a dispute about delta-v?
If the insurer questions your complaints because of a low delta-v, you can take the following steps:
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Medical evidence
Discuss which records are relevant with your medical adviser. Record when symptoms began and how they developed, including relevant pre-existing symptoms. Share information through the appropriate medical channel. -
Independent expertise
Ask an independent medical specialist to assess whether your complaints are consistent with the accident. A biomechanical expert can also be valuable. -
Emphasize the circumstances
Factors such as seating position, headrest function, and the angle of the collision play a major role. This can make the impact greater than insurers suggest. -
Seek legal assistance
A personal injury lawyer can help you refute the insurer’s positions and ensure that your complaints are taken seriously.
Eight questions to ask about a delta-v report
- Which vehicle and which phase of the collision were analysed?
- Which inputs were measured and which were assumed?
- Were photographs, repair records and pre-existing vehicle damage considered?
- How were the direction of impact and vehicle masses taken into account?
- What margins of uncertainty apply, and which assumptions change the result most?
- Were alternative collision scenarios considered?
- Which conclusions are technical and which require medical expertise?
- What additional information could change the conclusions?
Keep technical and medical questions separate
An accident reconstruction concerns the vehicles and the collision. A medical adviser or appropriately qualified medical expert addresses symptoms and medical questions. Establishing limitations and calculating lost income require their own reasoning; do not treat these steps as interchangeable.
The Medical Section of the Dutch Personal Injury Claims Code addresses proportionate collection and exchange of medical information. Discuss which records are relevant and the proper medical channel for sharing them. The IWMD 2025 questions can provide a framework for medical expertise, but the questions must fit the dispute.
Agree the purpose and costs before a second assessment
Ask for a defined assignment, a budget and clarity about who pays if the insurer refuses reimbursement. The answer depends on the legal basis and the type of investigation. A report about a disputed cause is not automatically treated like an assessment of the amount of covered damage. Read our guide to independent assessment costs and use the sample request there.
Checklist: Collecting evidence after an accident
Strong evidence is indispensable in discussions about delta-v and injury. The checklist below increases your chances of a successful personal injury claim:
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📸 Take photos of the vehicles, damage, road surface, and traffic situation.
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📝 Witness details note down (names, phone numbers, statements).
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🚑 Seek medical help immediately and have your symptoms immediately recorded by a GP or specialist.
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📂 Request your medical records from your GP, physiotherapist, or hospital.
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⏱️ Keep track of your symptoms in a diary: when they started, how often they return, what limitations do they cause?
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🚗 Collect accident file: police report, claim forms, correspondence with the insurer.
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🔧 Technical investigation (if possible): have cars or data recorders examined for speeds and impact force.
The better your file, the stronger your position with the insurer.
Role of Arslan Advocaten
At Arslan Advocaten we have extensive experience with whiplash and delta-v cases. We help victims by:
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strengthening the case file with medical and legal arguments,
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engaging independent experts,
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refuting insurers who rely solely on delta-v,
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assessing and pursuing compensation that can be supported by the evidence.
Frequently asked questions
What does delta-v mean?
It is the change in a vehicle’s velocity during a collision. It is not the driving speed before impact or a medical diagnosis.
Does a low delta-v automatically defeat an injury claim?
A delta-v figure alone does not resolve an individual claim. Review the underlying data and assumptions together with the medical evidence, claimed limitations and resulting loss. The outcome depends on the case file.
What can I ask the insurer for?
Request the complete report and annexes, the inputs and assumptions used, and a clear explanation of which part of your claim is disputed. Respond to specific findings with relevant documents.
Will the insurer pay for my own expert?
Not automatically. Define the investigation and budget first, and check the policy and legal basis for reimbursement. Agree with the expert who pays any amount that is not reimbursed.
