In a truck case, the evidence that proves what happened often belongs to the other side — and it does not last. The truck's engine and event data can be overwritten as it keeps running or is repaired, and companies are only required to keep logs and records for limited periods.
Because the trucking company controls much of this evidence and has little incentive to preserve proof of its own liability, a prompt legal demand — a preservation letter, sometimes called a spoliation letter — is used to formally require it to keep the truck, its data, and the records. Sent early, that demand can stop routine destruction.
That is why moving quickly matters even when the filing deadline is far off. The sooner the evidence is locked down, the stronger the claim. Waiting can mean losing proof that cannot be recreated.