Emergency Traffic Signal Systems
360VL engineers have extensive experience integrating AVL and computer aided dispatch (CAD) with traffic signal systems - both 170 and NEMA standard signal systems.
When traffic signals are combined with 911 and AVL systems, you have an incredibly powerful system that can help emergency responders get to incidents quicker, more safely, and save lives.
Even the simple business case of preventing a $750,000 ladder truck from getting T-boned in an intersection will pay for an emergency AVL system. The truly better part, though, is preventing the loss of life of the crew and the driver who accidentally blew through the intersection and didn't hear the sirens or see the truck coming.
Saving lives is why 360VL exists. Rapid-response, emergency GPS Tracking Saves Lives when combined with traffic signal systems and 911 CAD.
We have strong experience in how these systems work in the field. The day-to-day operations, design and improvement experience has left us with strong opinions as well.
We will not build line-of-sight preemption systems or recommend their purchase because fundamental flaws in these systems preclude them from ever working correctly in enough cases to make their purchase worthwhile.
Line of sight preemption systems do not work in many common cases including:
- Urban areas - a canyon-like environment in which line-of-sight is totally ineffective
- One-way streets create tight, one-block U-turns for emergency responders. The issue is that a signal can take time to set up for a preemption, clear pedestrians, and cannot change instantaneously. Any one-block U-turns created by one-way streets sets up an impossible preemption scenario for line-of-sight systems.
- Hilly terrain - an emergency responder, using a line-of-sight preemption system, may come over a hill with a light at the bottom will miss the opportunity to preempt the light because there isn't enough set-up time from the time of first sight until the responder is in the intersection.
- Congested intersections - some intersections in a city are so congested, unless the intersection can be cleared out well before the responder is even in sight, the intersection will block the responder's progress even if the intersection is preempted for the responder. To do this properly requires initiating the clearing of intersections 2, 3 or even 5 intersections ahead of where the responder is. If you throw some turns into that route, there's no way a line-of-sight system can properly clear congestion before the responder arrives at the intersection.
Only a birds-eye, centralized approach will solve these issues. That is the better way.
This includes the in-vehicle location hardware and user interfaces for the navigators. There's too much happening during an emergency response for technology to get in the way. In-vehicle user-interfaces have to be a natural extension to the people responding, their work-flow, and has to be as transparent as possible. If technology gets in the way, most benefits it provides will be washed out.
Major lesson: a picture is not worth a thousand words when it comes to in-vehicle user interfaces.
This counter-intuitive finding comes from direct experience with emergency response crews and how they use an emergency AVL system on a day-to-day basis.
Major lesson: don't combine functionality into a single faster, and therefore, hotter and less reliable CPU.
The temptation is to save by pushing as much functionality into a single in-vehicle CPU as possible. However, if not properly separated, functions running on a combined system can interact so that if one function misbehaves it can adversely affect all other functions. For example, if the user-interface application for the navigator over-taxes the CPU under some emergency situations, location reporting can be stalled or the system effectively crashed. We believe these functions should be physically separated by CPU.
The importance of a division of labor cannot be over-stressed. We also believe location services should run as an embedded application with the highest possible reliability built in to it. Without reliable location services, no other application built on emergency AVL will matter.
Please take advantage of our years of experience developing these types of systems for emergency responders so you don't end up making expensive mistakes that can be easily avoided. Do not spend any money on emergency AVL systems until you have talked with us first and we can share our real-world experience with you. Contact us for an initial consultation to see how emergency AVL systems can benefit you.
