On 11/30/2011 1:09 PM, Percival P. Cassidy wrote:
On 11/30/11 01:57 pm, Hell Toupee wrote:

What, is it still the 1970s where you live? 3M company developed the
OptiCom Emergency Vehicle Preemption system at least thirty years ago
and its use has expanded throughout the United States (and probably
elsewhere) since then.


I have never encountered this system and had never heard of it. If a
driver from another area is in an area where this system is used, how
would s/he know what it means and how to respond?

By observing the actions of the other drivers. And, if the emergency
vehicle is within sight or hearing distance, by observing its
approach. The white lights are in place to warn drivers that an
emergency vehicle is approaching the intersection. The system grants
the emergency vehicle the right of way, which entails either quickly
changing the traffic light, or keeping it green for the road the
vehicle is travelling.

The other drivers' responsibility in that situation is the same
everywhere - to get out of the emergency vehicle's way as soon as it
is safe do so.

This is simply one
more example of the downside of allowing every State (and even county
or municipality) make up its own rules instead of having a nationwide
uniform traffic code.

But the rule *is* uniform - get out of the vehicle's way as soon as
you can safely manage to do so. This system merely permits emergency
vehicles to trigger the traffic light to give it right of way. As a
safety feature, it also activates a white light to alert other drivers
that an approaching vehicle has triggered the light.

Incidentally, its use has expanded in some instances to permit
selected non-emergency vehicles to give themselves the right of way.
For instance, in some cities certain intersections on certain bus
routes can have the lights triggered by an approaching bus that is
equipped with the signal system.