Highway Safety and Vehicle Extrication

Highway emergency operations

The greatest hazard at a highway crash is the traffic still moving past it, and highway operations are organized around that fact. Only the first-arriving unit goes directly to the scene. Every other unit stages off the highway and waits there until it is requested, so that the roadway does not fill with apparatus that nobody is using.

The first unit parks to protect the people who will be working. The technique is called upstream blocking: the apparatus is positioned between oncoming traffic and the work zone, so that a vehicle which fails to stop strikes the apparatus rather than the crew. Crew members then step out only into the safe zone, and only after the whole crew has confirmed that traffic has in fact stopped.

Night operations add a hazard you can create for yourself. Your own headlights shine into the eyes of oncoming drivers, and a driver who is blinded cannot see your reflective vest either, so the vest stops protecting you. The correct setup after dark is red and amber warning lights on, headlights off, and directional boards operating.

PPE & managing hazards

Personal protective equipment (PPE) is selected according to the zone you are working in. Working in traffic calls for a reflective vest meeting the American National Standards Institute (ANSI) standard and a helmet; the high-visibility vest is federally mandated. Active extrication calls for full turnout gear, a helmet and eye protection. As a rule of thumb, match the level of protection worn by the workers around you.

The vehicle holds two hazards that catch rescuers out. An airbag that did not deploy in the collision remains a real danger during extrication, and turning off the ignition does not disable it; the battery must be disconnected. Energy-absorbing bumpers are the second. After an impact a bumper can be left loaded, holding the energy of the collision in its compressed state, so never stand directly in front of one.

Electrical hazards — the most dangerous invisible threat

Electricity is the most dangerous hazard on a crash scene precisely because there is nothing to see. Wood utility poles can carry up to 500,000 volts, and once a pole or its wires are involved you should assume that the entire area, including the ground you are standing on, could be energized. Treat every downed wire as live until a utility professional confirms otherwise, and never move a wire yourself.

Current spreading outward through the earth produces a ground gradient, a difference in voltage from one footstep to the next. The warning sign is a tingling in your legs, and it means you are already standing on energized ground. If you feel it, turn 180 degrees and shuffle away, keeping both feet in constant contact with the ground. Never hop, and never let your feet come together.

Vehicle fires & alternative-fuel vehicles

Call the fire department yourself for any vehicle fire, and never assume that someone else has already done it. An A:B:C dry chemical extinguisher will handle most vehicle fires. Where you stand matters as much as what you are holding: never stand in front of a truck wheel, because the tires can blow apart.

Alternative-fuel vehicles — hybrid, electric, natural gas and propane — carry hazards that a conventional gasoline vehicle does not, and when you are in doubt about one, do not intervene if intervening puts your own safety at risk. Confirm that the vehicle is truly off rather than merely silent. With a keyless ignition that means locating the fob and moving it well away from the vehicle.

10 phases of extrication

Extrication is taught as a sequence of ten phases, worked in this order:

1. Prepare.
2. Size up the scene.
3. Recognize and manage hazards.
4. Stabilize the vehicle.
5. Gain access to the patient.
6. Assess the patient.
7. Disentangle the patient.
8. Immobilize and extricate.
9. Transport.
10. Terminate the incident.

The phases do not change with the patient's condition, but the pace does. A stable patient can tolerate the slower techniques, while an unstable patient needs rapid extrication straight to a long board. The spinal principles are the same either way; only the speed is different.

Stabilizing a vehicle

The core rule is that every vehicle involved in a collision is unstable, regardless of how settled it appears. A car sitting squarely on its wheels can still roll or shift once rescuers begin working in and around it.

For a vehicle on its wheels, confirm that the engine is off, that the transmission is in park and that the parking brake is set, then take out the remaining movement with step chocks. A vehicle on its side or its roof demands more. Never let bystanders try to push it upright, and stabilize it with cribbing or struts before anyone attempts access.

Gaining access

Once the vehicle is stable, the guiding phrase is "try before you pry." Always try the door in the ordinary way first, because a door that simply opens costs nothing and saves the time that mechanical tools would take.

When the doors will not open, a window is the next choice. Most side and rear windows are tempered glass, which breaks into small rounded pieces, and that makes them the preferred access point over the laminated glass of the windshield. Cover the occupants with an aluminized blanket before you break a window near them.

Disentanglement — three-part plan

Disentanglement follows a plan in 3 parts, taken in order. Part 1 is the doors, part 2 is the roof, and part 3 is displacing the entire front end of the vehicle as one unit.

Taking the doors and then the roof buys you several things at once. It gives full access to the interior so that care can continue while the work goes on, it opens a large exit should a new hazard appear, it brings fresh air to the patient and the crew, and the faster access it provides improves the patient's chance of survival.

Displacing the front end brings the work close to the airbag system, so the sequence there is fixed. Disconnect the negative battery cable first. Stay clear of the airbag module and out of its deployment path, since a residual charge can remain even after the battery has been disconnected. Never cut or drill into the module itself.

The Nader pin

Every car sold in the United States since 1966 has a Nader pin, a case-hardened pin in the door latch that keeps the door from flying open in a crash and so prevents occupants from being ejected. It does that job well, and in doing it, it locks rescuers out as effectively as it holds occupants in. The crowbar method that once opened a door will not defeat it, and hydraulic spreaders are required instead. That trade is the recurring lesson of extrication: every improvement in occupant safety creates a new challenge for the rescuer.