Social Question

ibstubro's avatar

Are emergency vehicles ever able to influence traffic stop lights?

Asked by ibstubro (18804points) May 18th, 2016

Today I believe I saw a traffic stop light cycle to accommodate an oncoming ambulance.
Is that possible?
If not, why not? It seems like it would be easy enough for an emergency vehicle to send a signal to a traffic light enough ahead of time to ensure that the light was green when the EV arrived?

I’m going to verify any answers I get here, but I thought it would be interesting to others, so I open it for discussion.

Observing members: 0 Composing members: 0

9 Answers

zenvelo's avatar

Yes. It is called traffic signal preemption. There is a little doodad on top of the lights that can be triggered by approaching emergency vehicles.

YARNLADY's avatar

Most of the traffic lights on our major streets have a sensor so that emergency vehicles can adjust the signal.

kritiper's avatar

Yes, they can do that and they do it here.

Cruiser's avatar

Yes. At least where I live as @zenvelo mentions our lights have a “dodad” on top the traffic signals that will flash a bright white warning flash as the lights change in favor of the approaching emergency vehicle.

johnpowell's avatar

Yes. They can (or at least could) trigger them with a strobe light. A old school hacker buddy of mine in high school (think simulating the sound of coins dropping in a payphone for free long distance) figured out how to do it so he could set any light at a major intersection to green.

This was of course so amazingly illegal he only did it a few times just to prove he could.

SecondHandStoke's avatar

^ Thanks for your reply.

I will be investigating this for personal use.

ibstubro's avatar

I’d never heard of this before today. I’m surprised it isn’t mentioned on more TV shows and movies.

I live in the sticks and the nearest town is small enough that there probably aren’t many ‘doodads’. Given the number of times I’m in town at a stop light when there’s an emergency vehicle, it’s not surprising I’d not seen it before.

I guess the cops have this, too? I swear I’ve seen police cars blow through on red in the same town – almost certainly this year. Of course, they might have shorter starts and stops.

Mariah's avatar

Yes, in Worcester a popular intersection would turn red to allow only ambulances to go through, when I lived there. It’s as easy as using an EZpass esque system.

SecondHandStoke's avatar

“It’s as easy as using an EZpass esque system.”

Ahhhh… Faint praise.

I need to move some furniture. Oh, couldn’t be any problem there. I’ll just take my EZ Pass ‘sponder with me in my friends truck!

Weeks later:

What’s this? It’s a letter from so called EZ Pass… It’s not my bill? What could it be?

“Darling? EZ Pass has notified us of charging us a fine.”

“Fine? For what?”

“Our toll device did not match the vehicle’s tag number.”

“Ohh, That sounds EZ…”

Answer this question




to answer.
Your answer will be saved while you login or join.

Have a question? Ask Fluther!

What do you know more about?
Knowledge Networking @ Fluther