Comparison of Traffic Signal Requirements

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TRANSPORTATION LIGHTING

LED Traffic Signal Technology

	ITE: Vehicle Traffic Control Signal Heads April 1985	ITE: VTCSH Part 2: LED Vehicle Traffic Signal Modules June 1998	Draft European Standard: Traffic Control Equipment - Signal Heads January 1998	Japanese Standard April 1986	CIE: Suggestions from Light Signals for Traffic Control 1980	CIE: Review of the Official Recommendations for the Colors of Signal Lights 1994
Color boundaries: Red	0.998-x<=y y<=0.308	0.998-x<=y y<=0.308	y=0.290 red y=0.980-x purple y=0.320 yellow	0.835-0.774x<=y y<=0.335	y=0.290 red y=0.980-x purple y=0.320 yellow	y=0.300 y=0.290 y=0.980-x
Color boundaries: Yellow	0.411<=y<=0.452 0.995-x<=y	0.411<=y<=0.452 0.995-x<=y	y=0.387 red y=0.980-x white y=0.727x+0.054 green	0.932-0.918x<=y 0.036+0.611x<=y y<=0.109+0.65x	y=0.382 red y=0.790-0.667x white y=x-0.120 green	y=x-0.151 y=x-0.206 y=0.980-x
Color boundaries: Green	0.506-0.519<=y 0.150+1.068x<=y y<=0.730-x	0.506-0.519<=y 0.150+1.068x<=y y<=0.730-x[2]	y=0.726-0.726x yellow x=0.625y-0.041 white y=0.400 blue	x<=0.214 0.214<=y y<=0.499-0.474x	y=0.726-0.726x yellow x=0.625y white y=0.390-0.171x blue	y=0.726-0.726x x=0.625y-0.041 y=0.500-0.500x
Luminous intensity (cd): Red (in the reference axis)	Min=157 (d=200 mm) Min=399 (d=300 mm)[1]	Min=133, Max=800 (d=200 mm) Min=339, Max=800 (d=300 mm)[3]	PL1: Min=100, Max1=400, Max2=1100[4] PL2: Min=200, Max1=800, Max2=2000 PL3: Min=400, Max1=1000, Max2=2500	Min=240[5]	Min=200, urban and daytime 50<=intensity<=100, nighttime[6]
Luminous intensity (cd): Yellow (in the reference axis)	Min=726 (d=200 mm) Min=1848 (d=300 mm)[1]	Min=617, Max=3700 (d=200 mm) Min=1571, Max=3700 (d=300 mm)[3]	same as Red above	Min=240[5]	N/A
Luminous intensity (cd): Green (in the reference axis)	Min=314 (d=200 mm) Min=798 (d=300 mm)[1]	Min=267, Max=1600 (d=200 mm) Min=678, Max=1600 (d=300 mm)[3]	same as Red above	Min=240[5]	N/A
Uniformity	Intensity at each of 44 test points shall not be lower than 80% of required values. No more than 8 test points having values less than 90% of required values are allowed.		Min:Max>=1:10 (type E,W,M) Min:Max>=1:15 (type N)[7]		Min:Max>=1:5
Size	200 mm, 300 mm	200 mm, 300 mm	200 mm, 300 mm	250 mm, 300 mm	200 mm, 300 mm
Temperature	-40 to 74 C 0-100% humidity	-40 to 74 C	Class A: -15 to 60 C Class B: -25 to 55 C Class C: -40 to 40 C	-20 to 60 C 40-90% humidity

Notes

[1] The intensity value is the required value at the point where horizontal and vertical angles are 2.5 degrees from the reference axis. d indicates the diameter of the roundel signal head.
[2] The measured chromaticity coordinates of LED signal modules shall be between 500 and 650 nm.
[3] The required intensity value of an LED signal is 85% of that of a corresponding incandescent signal.
[4] Values are the required values in the reference axis. PL1, 2 and 3 indicate Performance Levels 1, 2 and 3. For the maximum intensity, Max1 is for Class 1 and Max2 is for Class 2.
[5] Values are the required values in the reference axis.
[6] Values are the required values in the reference axis. The nighttime condition exlcudes urban areas with bright surroundings and high-speed rural roads.
[7] Type E: extra wide beam signal; Type W: wide beam signal; Type M: medium wide beam signal; Type N: narrow beam signal.

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