Why some street lights use red as color?

Question

advantage or reason for using red color rather than others

Answer 1

It depends upon the reason for the red color. If it is made red by a colored lens then generally glare is reduced. My guess is that the red hue is present because of the gas or element present in the light source. Sodium light puts out a yellowish/orange color, florescent puts out white light etc.
Here are some elements and there flame test colors.

metal flame colour
barium light green
calcium brick red
copper blue/green
lead blue/white
potassium lilac
sodium bright orange

Answer 2

Considering Einsteins photon theory of light, Red light carries the least energy in the color spectrum(VIBGYOR).In other words it needs minimum energy to emit Red Colored Light.Sodium Vapoured Lamps emit Red Color and can be of Incandescent or Luminiscent type.

Since the energy input required to emit Red Light is the lowest(as the Red light photons carry minimum energy),hence Sodium Lamps are being increasingly used for application needing energy saving.

Answer 3

No ..I dont think street lights will be red in colour....
Only the "STOP" signal light will b red in coulor because....red has the longest wavelength and will be seen from the farthest distance....

Sreet lights do use Mercury vapour or the Sodium vapour lamps

Mercury vapour lamps give white light
Sodium vapour lamps give light orange color......Sodium vapour is the ideal choice and it gives intense light thats why it's prefered....

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Answer 4

Sodium lamps which emit light in the yellow/orange end of the spectrum are more efficient in energy use. Also observatories have asked cities to use them as they interfere less with their telescopes.
Energies in the red range (long wavelength) are lower than the blue and ultraviolet(short wavelength).
"For placements where light pollution is of prime importance (for example an observatory parking lot), low pressure sodium is preferred. Sodium emits light on only one wavelength, and therefore is the easiest to filter out."

Answer 5

The wave lengths at the red end of the spectrum have more penetrating ability. Thus they will be the the first visible in inclement weather. Red has been the standard for emergency vehcile for that reson.

Answer 6

Which part of the world you are living in?.May be some traffic signal or warning lamp in hazardous area,you assume as strret lamp because it was somewhere in a street.Otheriwse you have serious colour blindness and you see green light as red.Check with your doctor.

May be your question is confusing and you are asking about the paint colour.Red paint means DANGER in the world of electricity.

Answer 7

RED colour has the longest bandwidth in the spectrum. Hence it is the most visible colour to the human eye.

Hence RED light is used, in places where there is an upcoming danger or to stop the heading traffic.

This is why universally, RED indicated STOP.

Answer 8

red

Answer 9

street lights red in colour...u might be saying about mercury lamps...which blow due to heat and when its oveheated again goes off on its own...when its back to normal heat it lights up again...so its a engergy saving lamp or light..

Answer 10

as red color has the shortest wavelength so it doesnot scatters