Whenever someone is stopped by police because of a traffic violation or a regular check, does the police officer have the right to demand car documents and proof of insurance without a search warrant?
Please note that the question is about the car documents or anything other than the occupant's identification (which any officer has the right to demand).
As has already been said, as far as the vehicle registration, the officer likely already knows who the vehicle is registered to and whether it's expired or not before he walks up to your car, or at the least, he can easily find that information out.
The proof of insurance is a different matter. The officer will need to see it to know if you have insurance or not. To him, it doesn't matter what the reason is that you don't provide it to him. Left it at home, misplaced it, lost it, destroyed it, or just refuse to provide it because you feel you have the right to refuse. He can't "force" you to provide it (unless he is able to search your car and happens to find it there). He can only issue you a ticket for not providing it.
But your attitude could play a part in what happens next. Being upfront and letting the officer know you have left your documents at home could help your situation.
In my experience... one time that this sort of thing happened to me, the officer agreed to hold my drivers license and allowed me to bring the documents to the police station and retrieve my license.
Another time, in a parking related matter, I was issued a ticket, but I was allowed to bring the required documents to the police station where they then "invalidated" (cancelled) the ticket.
Of course this won't always work, and is not at all likely to work if you are far from home.
Keep in mind, (as far as I know, in most states) the real infraction is that you "don't have insurance"... that you failed to provide proof when asked, is secondary. In many cases (likely nearly all cases), if you show up in court and provide documents that your insurance is current, and was current at the time the ticket was issued, the judge (or the prosecutor) will likely dismiss the case with no penalties. But, what the officer has written down on the ticket about your attitude and what you told him at the time, may have an effect on how this all plays out.
First, police need probable cause to stop a vehicle. Something like a safety violation with the vehicle, or some type of moving violation. The specifics for a stop vary state to state.
Secondly, police have the right to ask for the driver's ID, Registration and in some states insurance. All the other passengers have no legal requirement to produce ID.
The police are allowed to ask for such things because of what is know as police power. Generally speaking, states are allowed to regulate behavior within their borders. They regulate and enforce the behavior through laws. So the laws in the states allow cops to ask for certain things. The tradition has its roots in the 10th Amendment which states that powers not given to the Federal Government are held by the states. The U.S. Supreme Court has upheld state laws that encroach on personal liberty (Jacobson v. Massachusetts) in order to maintain public order.
As has been mentioned, the request for certain information is provided by state law and is reasonable so the Supreme Court lets states police themselves.
It is not about needing to know. In most states LE has access to insurance information, and the production of an insurance document is redundant. However, as an example, in New York, failing to produce the insurance document (card) is punishable with up to 15 days in jail, a fine of up to $1500 and a civil penalty of $750. Production of the insurance document is INDEPENDENT of whether the car is actually insured or not.
For example, not producing the insurance card is presumptive evidence of failure to have insurance. However, producing the card, even if the insurance were to not be in effect, has the affirmative defense of not knowing about the fact that the insurance is not in effect.
Also note, that the driver at the roadside stop, is required to produce the card evidencing insurance, but it is the owner who is required to have insurance in effect.
It is also worth noting that most drivers, covered under a policy, will have coverage for a "borrowed" vehicle.
When you are detained (seized even) in a traffic stop, most likely the LEO is "regulating traffic" and can request these documents by asking you. You are presumed to be operating in traffic, and therefore your compliance is required.
Current registration is also in a database which is often available in the patrol car. Many cars have their database updated daily, and if one's registration was revoked or suspended that would be available to the LEO within 24 hours. However in most states the requirement to produce a registration document still exists, and if the LEO so chooses they can cite you for failing to produce the document, even though they know that the registration is valid.
So in short, a traffic stop is done under the presumption that you are engaging in a regulated activity, which is called "traffic" or "motor vehicle traffic" and that you are subject to the regulations which apply to that regulated activity. That includes production of insurance, registration and driver license documents, and could include other documents. Failure to provide those documents makes one subject to consequences under the regulations, statutes, codes and perhaps even policy.
