WA Radio Scanner Users' Group

Hi Folks

Does anyone know why the WA police put their emergency lights on backwards - red on the right, blue on the left?

WA Car


Victorian Car

So the baddies know how much time they have at a crime scene when they see lights coming in the distance.

Blue light right, I'm alright

Red light right, get out of sight



Walks.

Good one, Walks

I'm more worried about the visibility of unmarked vehicles. Had to jam the brakes on for one coming off the freeway the other night that didn't have a roof beacon at all = no side lights

Hrm well why talk about, when you can see: http://www.youtube.com/watch?v=r4zpGnVZ6sg

yorky wrote:I'm more worried about the visibility of unmarked vehicles. Had to jam the brakes on for one coming off the freeway the other night that didn't have a roof beacon at all = no side lights

At night it's easy but during the day, yeah, can be hard. I've seen unmarked cars elsewhere that have little wig-wag lights near the b-pillar on the bottom of the passenger side windows. Would seem to be the trick to solving the side visibility thing... <shrug>

I have trawled back through all of my Emergency Services vehicles pics and can present you with the following observations based on the pics i have:

Of all of my WAPol vehicle pics (including bikes) that have colour visible beacons (as some of the new HILED lights appear white/clear until activated), the red beacon is on the right, that is over the driver, except for the following four examples;

Blue over driver=
An old Mobile Command Post truck that was in South Hedland
The former TK103 (Commodore wagon)
One of the Booze Buses
Cannington Mobile Command Post JC601


My other Police vehicle pics indicate:
SA (2 vehicles) - Red over driver
Qld (4 vehicles) - Blue over driver
NSW (7 vehicles) - Blue over driver
Federal (5 vehicles) - Blue over driver
Singapore (3 vehicles) - Blue over driver


It would also appear that in WA, with a few exceptions, that Ambulances are predominantly Red over the driver and that fire appliances are predominantly Blue over the driver.

auntys_eyes wrote:I have trawled back through all of my Emergency Services vehicles pics and can present you with the following observations based on the pics i have:

Thanks Auntys_eyes. Interesting. It's not a huge big deal, but given that the standard is always for red lights to be on the left of a vehicle (aeroplanes, boats etc) I was curious if there was any particular reason for the reversal.

Sorry for the late reply but i have a theory as to why WA use red over right as opposed to blue over right.

I believe red is over the right because when an emergency vehicle is stationary the majority of the time it is on the correct side of the road usually parked towards the left of the lane forcing motorists to pass the vehicle on the right. Therefore it would make sense to have the brightest and most distinguishable light on the side of the vehicle in which most motorists pass.

The human eye uses various rods and cones to pick up and distinguish colour. The cones responsible for sensitivity to red (L) are sensitive from 500m to 700nm with a peak efficiency range of between 564 – 580 nm. Blue cones (S) on the other hand have a much narrower sensitivity range of 400 – 500 nm with a peak efficiency range of 420nm to 440nm.

We also are better at discriminating between similar colours at around 500nm and 600 nm (blue and green) where we can generally perceive differences of 1 nm however outside of that we generally need 2.5nm of difference to perceive a difference (like in blue).

(This however is different in low light conditions when rods supplement the cones in order to pick up more light, Rods respond better to shorter wavelengths so sensitivity is greater for blue at night. )
Because of all this during day light hours red is much easier to pick up than blue. For example if you were to use clear coloured bulbs behind red and blue filers the bulb behind the blue filter would have to be 7 times brighter than the one under the red filter in order for both to be seen at the same luminescence.

TL;DR – Red is easier to see than blue so it makes sense for the red to be on the side of the vehicle traffic is moving past when pulled over to the left.


Dunn, Kerry, and Deborah Tunnicliff. The Safety and Effectiveness of Emergency Vehicle Lighting. Centre for Accident Research and Road Safety Queensland, 2003.

"Gardengallivant". Yahoo Answers. 2008. http://answers.yahoo.com/question/index ... 443AAnrKVm.

I saw a south west k9 with blue over driver but also had a red flashing blinker under the rotating light.
Passsenger had red rotating light and blue flashing blinker... Gave a purple effect... Can't recall the style of light bar but I'm sure someone will inform...
Was Rx 6xx i think. Vz wagon. Looked like it was rady for retirement.

yorky wrote:Hrm well why talk about, when you can see: http://www.youtube.com/watch?v=r4zpGnVZ6sg

Hi Yorky

What dash camera / mic combo do you use?
did it feed the display info automatically (gps co ordinated time etc) or do you run a secondary device /program to get that?

Norty,

For that video I was using a Logitech 5000, inbuilt mic. Bluetooth GPS, all into a laptop using a free application Xport with minicam.

yorky wrote:Xport with minicam.

I think you just solved three of my problems.. splitting a real serial port into multiple virtual ports, a handy webcam program and how to stop Windows detecting a serial GPS or weather station as a bloody serial mouse (because everybody uses a serial mouse these days).

Yep and I've talked to the developer on MP3car.com as well and he was always happy to help. The programs through user feedback went leaps and bounds over the first releases within the course of a year or so and is pretty much stable now.

Xport alone lets me use the GPS for about four programs I have installed to share it at once.

Here, I don't believe it matters. In fact, I'm sure it doesn't. Our city police have Red over driver, as well as our local university police. However, I'm not 100% on the county vehicles. The small towns that are all a part of our County Sheriff's Dept. are usually the same, I believe, however I do think maybe one could be reversed.. Though, I don't think it's a set rule..

What is set in stone is the colors of lights as per each type of service:

Red and White (As well as Amber) are used by Fire/EMS. These are also allowed on personal vehicles, whether you're a member of a fire department that allows you to respond to a scene, or not. However, if you are not, you aren't allowed to use them while the vehicle is in motion.

Blue (as well as red, white, and amber) are used by Police vehicles ONLY. Blue lights inside the vehicle (Such as speakers, radios, etc) are all prohibited, and can get you a nasty fine for impersonating an officer.

As per state law, all emergency vehicles must have some type of amber light flashing to the back while the vehicle is responding to an emergency scene. Most Fire/EMS vehicles at the time of that law passing didn't have an amber light, so they use their arrow stick on a "Chaos" pattern (See here 0:13), which complies. Police as well, however new vehicles need to have the dedicated light that is amber.

On a side note, all emergency vehicles need to have High Visibility Striping on the rear of the vehicle starting in 2012 (I believe)