Too many close calls. Too many pieces of fire apparatus damaged or destroyed. Too many firefighter deaths and injuries. And we’re not talking about firefighting operations.
We’re talking about secondary traffic crashes caused by D drivers. I spoke with Fire Chief Judy Thill Smith of the Inver Grove Heights (Minnesota) Fire Department, who’s been teaching firefighters about the dangers of operating near traffic since 2012. Smith describes five types of D drivers that pose a danger to firefighters:
- Drunk
- Drugged
- Drowsy
- Distracted
- Dumb
“Predictable is preventable.” That phrase has been made famous by noted public safety risk SME, Gordon Graham. While it’s true we can predict that secondary crashes can occur, there’s not much we can do prevent one of those D drivers from showing up. But we can be better prepared to receive such an uninvited guest.
The Federal Highway Administration’s Manual of Uniform Traffic Control Devices notes, “The ability to quickly install proper temporary traffic controls might greatly reduce the effects of an incident, such as secondary crashes or excessive traffic delays. An essential part of fire, rescue, spill clean-up, highway agency and enforcement activities is the proper control of road users through the traffic incident management area in order to protect responders, victims, and other personnel at the site.”
The MUTCD lists three general classes of traffic incident duration, each of which has unique traffic control characteristics and needs:
- Major. Traffic incidents involving hazardous materials, fatal traffic crashes involving numerous vehicles and other natural or man-made disasters. These traffic incidents typically involve closing all or part of a roadway facility for a period exceeding two hours.
- Intermediate. Traffic incidents that affect travel lanes for a time period of 30 minutes to two hours, and usually require traffic control on the scene to divert road users past the blockage. Full roadway closures might be needed for short periods during traffic incident clearance to allow traffic incident responders to accomplish their tasks.
- Minor. Traffic incidents that typically involve disabled vehicles and minor crashes that result in lane closures of less than 30 minutes. On-scene responders typically include law enforcement and towing companies, and occasionally highway agency service patrol vehicles.
The temporary traffic control zone
It’s a matter of life or death that every firefighter knows what a temporary traffic control zone (TTCZ) consists of and knows how to set up any portion of the TTCZ when assigned by the incident commander. Yes, it’s that important.
The MUTCD specifies the use of four distinct areas for traffic control:
- The advance warning area
- The transition area
- The activity area
- The termination area
Remember incident priorities from your structural firefighting and incident command classes? Life safety, incident stabilization and property conservation, right? Approached in that order, and you don’t move from one to the next until you’ve addressed the higher priority. So, let’s apply that same thinking to follow three priorities for responding to a motor vehicle crash on a road or highway.
Priority No. 1 – Life safety
The life safety of the responding firefighters, personnel and any civilians involved in the crash is priority No. 1. Blocking with fire apparatus to create the initial buffer space must take place to protect first responders and civilians.
Priority No. 2 – Create the temporary traffic control zone
The next priority is to set up the other three components of the TTCZ in this order:
- Transition area. The area where upstream traffic is moved out of its normal path (e.g., three lanes to only two lanes on the left). Typically, a taper will be created with traffic cones to accomplish this movement of vehicular traffic. OSHA provides the following criteria. For example, where the posted speed limit is 45 MPH, and the lane width (of the lane you’re moving vehicles out of) is 10 feet, then your taper would begin 450 feet back from the buffer zone, and your traffic cones should be spaced no more than 45 feet apart.
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Advanced warning area. This is where drivers are informed of what to expect. The advance warning may vary from a single sign or flashing lights on a vehicle to a series of signs in advance of the temporary traffic control zone transition area.
A rule of thumb for warning sign or device placement prior to the transition area for urban areas is four to eight times the speed limit in feet, with the high end of the range being used when speeds are relatively high (e.g., 35 MPH x 4 = 140 feet prior to the transition area).
Rural roadways are characterized by higher speeds. Warning sign spacing is substantially longer – from 8 to 12 times the speed limit in feet. Two or more advance warning signs are normally used in these conditions. The advance warning area should extend 1,500 feet or more in open highway conditions.
The true test of sign spacing adequacy is to evaluate how much time the driver has to perceive and react to the condition ahead. In this regard, the use of speed, roadway condition and related driver expectancy must be considered in order to derive a practical sign spacing distance.
- Termination area. Here is where your traffic control devices guide motorists back to the normal flow of traffic. Don’t shortchange your safety by making the termination area too short. Leave plenty of close roadway for emergency apparatus and vehicles to safely get into the flow of traffic.
Priority No. 3 – Demobilize the TTCZ
Once emergency operations are completed, the TTCZ should be taken down, starting at the buffer zone and working backwards. All personnel should continue to exercise extreme caution until the last unit assigned to the crash leaves the scene. All apparatus and personnel not assigned to the demobilization of the TTCZ should clear the scene and return to quarters.
