There can be situations where some or all of the blame is unjustly placed on an injured driver for causing an accident and the conditions of the roadway, where the accident happened, are not fully considered. A thorough accident investigation should identify all parties who might share the fault, including whether a public body, charged with building and maintaining the particular roadway, failed to perform some act that they had a duty to perform. Public bodies have a lot of discretion as to how they build and maintain roadways so it is not automatic that they will have liability for their lack of preemptive action. Public bodies can decide they don't have money to rework a poorly graded section of road, but they may still have a duty to install less expensive signs warning drivers of the sunken grade ahead.
To ascertain all possible causes of an automobile accident and properly assign liability, one may need to hire an accident reconstruction expert to review the situation and give their professional opinion as to all contributing causes of the accident. A complete investigation should also look into whether the roadway where the accident happened has had a lot of accidents in the past and look at whether the construction of the roadway or the signage or the posted speed are materiel factors in the high rate of accidents.
Such an investigation could take a while. To preserve one's right to sue a public entity who may later be proven to be culpable in the accident, it is extremely important to send a generic Tort Claims Notice Letter to all public bodies who could possible have responsibility within180 days (six months) of date of the accident. You don't have to know for certain that there is any liability on the part of a public body to send such a letter. All the letter has to say is that this is a Tort Claims Notice Letter and that there was an accident (and give the date, time, location, information as to the cars and drivers involved, etc) and state that the agency may be named in a subsequent lawsuit for damages.
The cost of sending the letter is very low. Conversely the consequences of not sending the letter can be costly. Sending such a letter gives the injured party time to explore all theories of liability which may help lead to a full recovery of damages. It should be a standard practice to send a Tort Claims Notice Letter in all accidents just to preserve one's right to add a public body as a defendant later on should it prove necessary or desirable to do so.
This is not something that a lay person should do on their own because it is critical to identify any and all public bodies which may have jurisdiction over a particular section of highway. Also one needs to be able to prove that the letter was sent on a certain date and was sent to the correct address and the appropriate responsible party. One needs the assistance of an Attorney to insure that this is done correctly.
Whether or not a full investigation including the cost of hiring an accident reconstruction expert is justified or needed is a decision best made on a case by case basis. It is advisable however to keep one's options open until the extent of the client's injuries and the question of liability has been fully explored.
Keep in mind that in Oregon one can only recover one's damages if one is either not at fault or has 50% or less of the total assigned partial fault. Adding a public body to the case who may share in the fault, may make the difference as to whether one can recover damages at all.