L&S - Traffic Signal Preemption Systems

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sjohnson0813

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I've read a number of discussions on running L&S on this thread, and I like that the latest one actually addressed different states legal rights for emergency vehicles, but I haven't seen anyone discuss traffic signal preemption setups.

I first encountered it when I lived in Las Vegas and think its the best thing ever, and wished they had it down here in South Carolina. I'm wondering if its not as well known as I thought it would be by now. Or was it abandoned for some reason I'm not aware of?

The short is that traffic signals are equipped with a sensor, and your emergency vehicles are equipped with a transmitter (the Vegas ones used an IR transmitter rigged in with your light bar circuit). About 300-500 yards from the traffic signal, it detects the transmitter and initiates a preemptive override giving your direction of travel all green, and all other direction full red.

No more running red lights, as they all turn green. Additionally vehicles stopped at the red light, that would normally be an obstacle to navigate around, now have a green light and have somewhere to go to get out of your way.

I googled up a 2006 case study from the US DOT Bureau of Transportation Statistics website (which does list a few other cities), but since I'm new to the forum and rarely post, it won't let me add the url. I'm sure you can find it on your own.

Anybody else experience this.
 
The Opticom is the device you're speaking of. It's expensive for cities to install because it has to be at every intersection to be effective. We have it on the major roads here, and while it does work, during the summer there is so much traffic, it doesn't seem to make any difference.
 
This does seem like a good idea. It doesn't have to be on every intersection. Only the intersections that seem really busy, like in my trip to a particular hospital, I have to cross a highway with traffic lights. It is often pretty ridiculous to run lights and sirens through the red light.

I'm just wondering how much something like this would cost per intersection and per rig.
 
They have these in Cary, NC. Only the Cary EMS trucks have the transmitters onboard. If another unit is covering the area, they can't use the systems.
 
Ahhhh yes the opticom system. We use the system and it works great the only downfall was that if we parked by an intersection the light would stay green until we left. So they made it be disabled when the ambulance was placed in park.

Police opticom has first priority. Fire has second. And ambulances have third.
 
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firefite said:
Police opticom has first priority. Fire has second. And ambulances have third.
Click to expand...
...the ambulances will have to wait their turn.
[youtube]http://www.youtube.com/watch?v=s9CKhyfFe4I[/youtube]


If an area is looking at getting Opticom, try to work with all of the local emergency agencies, as well as the local public transit agency. The Opticom system can be set up to also extend green lights if a bus is coming (different agencies are differentiated by the frequency of the flashes).
 
Opticom is great, especially at those intersections that don't want to change at 0200 when there's no traffic

Sent from my DROIDX using Tapatalk
 
Why not turn ALL directions red? It seems that if my direction is green, and I'm passing to the left, there is still a chance a guy on his phone or who has his radio up would turn left in front of me. If it's all red, then only I can go!
 
WuLabsWuTecH said:
Why not turn ALL directions red? It seems that if my direction is green, and I'm passing to the left, there is still a chance a guy on his phone or who has his radio up would turn left in front of me. If it's all red, then only I can go!
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If it's all red, traffic can't clear in front of you.

For instance, a busy road with a high un-crossable median for several miles. The all red system would be useless there.

There's also a chance for someone to make a right turn on red from the cross traffic towards your vehicle. That's why YOU have to leave room for everyone else's mistakes.
 
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WuLabsWuTecH said:
Why not turn ALL directions red? It seems that if my direction is green, and I'm passing to the left, there is still a chance a guy on his phone or who has his radio up would turn left in front of me. If it's all red, then only I can go!
Click to expand...

Or you then find yourself with total gridlock, not benefiting anyone. You're chances of getting through un-phased are a lot better when your light is green. It also reduces liability issues should an MVC occur because you have the right of way.
 
WuLabsWuTecH said:
Why not turn ALL directions red? It seems that if my direction is green, and I'm passing to the left, there is still a chance a guy on his phone or who has his radio up would turn left in front of me. If it's all red, then only I can go!
Click to expand...

The point of the opticom system is to turn traffic lights green in your direction so that traffic clears so you can go safely thru without having to cross into oncoming traffic or shut down. If the system works correctly the light will be green a while before you reach the intersection.

And it would be pointless to turn all directions red. We (at least for my company) are not allowed to "force or push" cars thru a red light under any condition.
 
WuLabsWuTecH said:
Why not turn ALL directions red? It seems that if my direction is green, and I'm passing to the left, there is still a chance a guy on his phone or who has his radio up would turn left in front of me. If it's all red, then only I can go!
Click to expand...

That's what I was thinking about too. What could help with that are those rumbler sirens too. If your town can afford these systems, they sure as hell can afford a sub-woofer for your siren.

[youtube]http://www.youtube.com/watch?v=fVdUUyGrz2o[/youtube]

It sounds funny, but it is very effective. It practically vibrates the car. We don't have it here, but I've seen a demonstration of it at a conference.
 
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Here in our city all intersections have it installed an it works great to reduce the amount of crossings against the light. Priority here is set up Fire > EMS > Bus (when they are a certain amount of time behind schedule).
 
Here's a question. I live in BFE. There is absolutely no need for a system like this in rural America. I'm certain there have been studies performed regarding the need for a system like this in metropolitan areas. How much time is saved versus stopping at all lights on a L&S call?
 
MSDeltaFlt said:
Here's a question. I live in BFE. There is absolutely no need for a system like this in rural America. I'm certain there have been studies performed regarding the need for a system like this in metropolitan areas. How much time is saved versus stopping at all lights on a L&S call?
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It's not the not stopping at red lights, it's the stopping of the cross traffic and turning your direction green, so vehicles can clear from your path.

As I mentioned, in my area, there is so much traffic near the beach, Opticom or not, we're going to be delayed by gridlock.
 
n7lxi said:
It's not the not stopping at red lights, it's the stopping of the cross traffic and turning your direction green, so vehicles can clear from your path.

As I mentioned, in my area, there is so much traffic near the beach, Opticom or not, we're going to be delayed by gridlock.
Click to expand...

Regardless. Someone's bound to have done studies. How much time would be saved versus running L&S anyway? Remember, when P1 lay people can tend to either merge the wrong way, merge to quickly in front of others, and or stop dead in their tracks which can, and usually does, endanger everyone around them including that great big truck with all the flashy lights behind them (as in you).

Safety for everybody is what matters most. The needs of the many outweigh the needs of the few, or the one.

So what do the studies say?
 
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All the studies I've ever seen pertaining to L&S usage has always been on the return trip to the hospital, and not on the initial response.
 
MSDeltaFlt said:
How much time is saved versus stopping at all lights on a L&S call?
Click to expand...

What I would like to see, in terms of signal preemption studies, is normal traffic vs L/S vs preemption alone vs L/S with preemption.
 
Linuss said:
All the studies I've ever seen pertaining to L&S usage has always been on the return trip to the hospital, and not on the initial response.
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The vast majority of citizens in my areas either never took driver's ed or Have forgotten completely what they were taught. I Have lost count of how many wrecks That almost happened going to a call That Would have been labeled my fault because I was the medic on the Call and my truck was running code regardless of how conservative/safe me or my partner were driving.

Their lack of situational awareness would have been my fault.
 
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