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TRANSPORTATION LIGHTING

LED Traffic Signal Technology

Comparison of Traffic Signal Requirements

 

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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