Loss of Area Coverage Efficacy of Fixed LED Warning Lights vs. Rotating Lights(Halogen or LED)

[QUICKONE]

Recently Doctors with the Journal of Emergency Medical Services (JEMS) opined that a Code 3 Response (with Lights and Siren) does NOT save overall response time and is unsafe.

I have over 20 yrs operating different types of Emergency Vehicles, including an engineering background), and I disagree with the JEMS Opinion, (as these Medical Professional are outside their scope of expertise).

The Case Against EMS Red Lights and Siren Responses

There are several engineering factors that the Layperson fails to take into consideration when evaluating current LED Emergency Warning Lights, (somethimes refered to Signal Variabilty);

1) The Photometics of Fixed LED Lightheads (non moving)are significantly different from the original Rotating Incandescent/Halogen Sealed Beams;
2) The coverage areas are also different, as the Rotating Lighthead has the potential of covering 360 degrees, while the Fixed LED Lighthead can cover 180 degrees at best;
3) The Flash Rate, Flash Duration and Flash Intensity are significantly different;
4) The LEDs produce a different type and color of light output that effects the interpretation of the light by a person.

In the late 1970's numerous scientific studies were conducted on the then current day emergency warning systems. Photometrics, Optomolgy and Physical all came into play in an attempt to determine which warning lights were most effective.

IMHO besides the inadequacies of LED Warning Systems, the problems we have with Civilian vs Emergency Vehicle Accidents are multifaceted including, but not limited to;

1) Today's Drivers are mostly self-taught and have ingrained bad driving habits. Most Drivers have no concept of Defensive Driving;
2) Today's Drivers between the ages of 15 to 40 have the attention span of an OCD-4 Year-Old in a Candy Store;
3) 80-90% of these Drivers are also operating an Electronic Device while driving.
4) In Arizona, the State Police determined that approximately >70% of Drivers age 18-40 were driving under the influence of Marijuana.

These factors significantly effect Situational Awareness and Reaction Times. Yet no one is addresses these driver safety issues.

Here are the Photometic Studies I'm referring to;
NIST Psycho- physical Tests of the Conspicuities of Emergency Vehicle Warning Lights 1979

NIJ NAT'L INST. OF STAND & TECH Publication 480-37 Reference NBS Publl - cations 1 I i •QC 100 ,U57 NO. ^80-37 1981 Emergency Vehicle Warning Systems

 

[shues]

Consider, as a thought experiment, a response with no other motorists on the road. Overall response time is reduced by all of the time not spent waiting for signals to cycle at controlled intersections.

 

[QUICKONE]

Agreed,

Medical Professional should stay in their Wheelhouse...just as I wouldn't attempt Brain Surgery.

They have very little traffic flow experience and the factor(s) that affect it.

 

[Sparky_911]

For the back half of your post in regards to the other idiot motorists on the road....no amount of lights/sirens in the world would fix that.

That said, modern led lighting may not be the most effective, but if it was detrimental to responses and causing more accidents then the industry wouldn't use them.

To add to that, most 911 centers use EMD (Emergency Medical Dispatch) software/protocols and medical control (at least in my state) governs the hot/cold ALS/BLS response levels. This has proven to reduce apparatus accidents (liability) and has not been detrimental to patient care. As with everything else these days, liability and risk in the public safety arena is top priority.

 

[QUICKONE]

For the back half of your post in regards to the other idiot motorists on the road....no amount of lights/sirens in the world would fix that.

That said, modern led lighting may not be the most effective, but if it was detrimental to responses and causing more accidents then the industry wouldn't use them.

To add to that, most 911 centers use EMD (Emergency Medical Dispatch) software/protocols and medical control (at least in my state) governs the hot/cold ALS/BLS response levels. This has proven to reduce apparatus accidents (liability) and has not been detrimental to patient care. As with everything else these days, liability and risk in the public safety arena is top priority.

Btw, 70% of Arizona is considered Rural and are located over 1 hour away from a Level 1 Trauma Center.

Most Rural Counties cannot afford upgraded dispatch centers and are still running 1980's style technology. There are only two large Metro areas in AZ. that have EMD type 911 dispatch centers.

To add insult to injury; Our new Lib Governor Hobbs took 10 Million in 2024 from the Rural Fire Grant Fund and re-programmed it to house and support the newly arrivals of illegal aliens. 99% of Rural Fire Departments rely on this Grant money for the majority of their discretionary spending, (like equipment and training).