Traffic accidents on a major interstate

You might consider contacting your local office of the highway patrol and see if they have a public information officer or the equivalent. Let them know youre writing a book or story and ask if you can do a short informational interview. If they do youve got the best source for this type of thing. Ive done informational interviews in the past and it is usually no big thing if youve got your questions in hand before you make the calls.

It's hard to answer in the abstract. There's a competing need for assessing the situation (how many ambulances to call and whether some behavior needs to be controlled) and making sure the other road users are safe. This has to be balanced against when the next unit(s) will be arriving.

Usually a police officer will park in the breakdown lane on the side where the accident is, and start to get oncoming cars into the lane(s) that are clear. If the officer is lucky, the cars will traffic jam themselves, getting their speed down to a safe level.

Communication is one of the important tasks of the first on scene. Should oncoming units go in hot (lights, sirens, pushing traffic) and should they slow down?

First fire engine in will physically block the traffic lane(s) containing the accident. You park it with the wheels angled so that if someone hits it, it will roll in a safe direction (if possible). A fire truck weighs about 30 - 40 K pounds, and can deal with most cars hitting it. They make good safety barriers, which police cruisers do not.

Best of luck,

Jim Clark-Dawe

Perhaps a better way to approach this dilemma is to sketch out the scene you have floating around in your head - actually drawn on paper - and then visit a DPS location, and then a local fire station, and then a local police station, and gather response information from all of them on their standard operating procedures. Depending on the severity of the accident, number of victims, etc., you might even want information on CareFlight helicopter response, Medical Examiner response and so on. Their answers might totally reshape your scene...

Just from listening to so many Atlanta traffic reports - if there's a death involved, the road is usually closed for one or more hours in addition to the cleanup time while they thoroughly investigate the accident/scene. I've also heard of authorities closing off a road (usually midday, not during rush hour) to recreate an accident that had happened there days or weeks earlier.

Where on I-35? There are long stretches of interstate in the middle of nowhere. How an accident is handled in Dallas or Fort Worth proper would be handled far different than from an accident near the Oklahoma/Kansas border.

Mmm, I've been on that stretch, but it's been many years ago. As I recall, there are also good shoulders on the right and left, as well as the median.

If it's just the wrecked cars and a DPS trooper, the trooper would first check on the status of the cars' occupants. If no immediate attention required (pulling someone out of a car before it exploded, performing CPR or stopping arterial blood gushes), he would probably place flares in the traffic lane(s) behind the crash, to alert oncoming vehicles. Then he'd park the cruiser between the flares and the wreck.

If ambulances weren't required immediately (or at all), most likely the tow trucks would come next and move the cars out of the traffic lanes. And then the drivers would argue about who was at fault, as the passengers all took videos with their cameras and rapidly posted them to Facebook and Twitter, so the world would know about the wreck.

I've been on a lot of road trips throughout the US, as well as commuting within the Greater Toronto Area so I've seen my share of closed-off highways.

That said, OP, it completely depends.

It depends on how damaged the cars involved were (are they still drive-able, did any catch fire, etc.) how many vehicles ended up involved, whether there were commercial vehicles - particularly passenger busses, any serious injuries/fatalities or any fails to remain in the case of more serious collisions.