There is now reasonably standardized Traffic Incident Management (TIM) training, and it is required or expected that all responders have TIM training.
There is training and good practice and there is reality. Given the recent spate of incidents where State Police cars, fire trucks, and ambulances have been hit while at a scene, it is no wonder that traffic is shut down. Lt. Brad Clark, a firefighter in Hanover County, was killed and three others firefighters were injured after their firetruck was rear-ended on I-295 in Hanover County back in October.
Agree that responders and response vehicles getting hit at the scene is an ongoing and serious problem, in part since TIM training is not provided to the driving population.
We heard about the death of Fire Lt. Clark up here too. Sounds like the driver of the striking truck was guilty of distracted or drowsy driving, or maybe both - and definitely reckless driving.
The TIMS training (I've taken it, I'm an extrication tech with the rescue squad) covers how to set up a scene with cones, flares, and equipment staging to warn oncoming traffic and protect people on the scene, but when a tractor-trailer comes barreling into the scene at speed, all bets are off. This was the case in Hanover, with the truck driver being charged with reckless driving and having inoperable brakes. The feeling is it is better to shut down all lanes until most of the scene is clear, then let traffic start moving when most of the danger to responders is over.
I have no disagreement with a total shut-down .- at least until the patient or patient has been transported, perhaps especially if it is a "middle of the night" incident, when traffic volumes are lower but speeds are higher.
Here in Montgomery County (Maryland), a Bethesda-Chevy Chase Rescue Squad ambulance was struck at a crash scene on the Inner Loop I-495 a few miles north of Virginia a few years ago. And on I-270 in 2017, we had a Maryland State Fire Marshal and an FBI special agent who had stopped at the scene of a crash to render assistance (the fire marshal was also a volunteer firefighter) and both were killed by a reckless driver who drove into the scene).
Maryland's reckless driving laws make it hard for police to charge and the states' attorneys to convict on reckless driving, even in egregious cases like this, thanks to obstruction by ex-Delegate Joseph F. "Joe" Vallario Jr. (D-23B), who was the chair of the House Judicial Committee for many years. Vallario was (and is) an attorney that represents drunk and reckless drivers in the state courts, and also felt he should represent them in the Maryland General Assembly, but fortunately he was defeated for re-election last year (2018 primary election), and I hope that there will be efforts to toughen reckless and drunk driving laws now that he is gone from Annapolis.
Adding a lane to I-81 northbound down Christiansburg Mountain would help in a lot of the incidents that occur, by providing that much more space to work in and to have more room to allow one lane (or shoulder) to open quicker to get traffic moving again.
Might also be nice southbound for similar reasons.