Danish technical handbook for VMS What signs are VMS ?

Danish technical handbook for VMS

What signs are VMS ?

Variable Message Signs are signs that can change between two or more sign faces including blank or neutral

This is not a variable message sign

A variable messagesign must not alternatebetween messages, orflash with text, symbolor frame, or showmotion symbols.

Different technologies present different options and limitations

Danish technical handbook for VMS

Different technologies with different options/limitations

Rotating prism

Flip disc matrix

Light guide

LED

Particular options/limitations of variable message signs:

1) distinguish between categories 1, 2 and 3

5) criteria for continuous signs, quality of discontinuous signs

2) monochrome is only accepted for text3) retroreflective signs shall be illuminated4) for some luminous signs, the attention achieved with the opposite contrast is considered an advantage. Other VMS shall have normal contrast

Concepts/requirements in the handbook:

- limitations in the number and types of messages 1) - monochrome or with colour 2) - luminous or retroreflective 3)

- normal or opposite contrast 4)

- continuous or discontinuous 5)

1) three categories:

1 a number of predetermined messages2 a predetermined number of characters and lines3 free display of characters and symbols (full graphic)

2) monochrome is only accepted for text:

Red borders have to be red, white parts have to be white (not yellow)

3) retroreflective signs shall be illuminated:

The same criteria as for fixed signs are applied.

Some details:

continuous signs (gaps between elements):discontinuous signs:(gaps between elements and stroke width)

s

maximum 10% of s

5) criteria for continuous signs, quality of discontinuous signs

maximum 12 mmand 5% of h

h

6 elementer

3 elementer

1 element

2 elementer

2 elementer

Some details:

Quality: poor medium good continuous

The font of Danish Road Signs has to be approximated

How big must the sign face be ?

Danish technical handbook for VMS

Quality of letters Maximum reading distance S

Poor MedimumGood

4 m per cm letter height5 m per cm letter height6 m per cm letter height

The necessary reading time is t = 2+n/3 seconds, where n is the number of standard informations on the sign(for instance symbols and city names)

Basis:

This calls for a maximum reading distance D = a+Vt, where: - a is the distance where reading must stop - V is the driving speed in metres per second

Demand:

Supply:

Driving speed

50 km/h 70 km/h 90 km/h 110 km/h 130 km/h

n ** letter height (capitals)

1 137 143* 159 170* 180 202* 202 202* 224 240*

2 145 143* 170 170* 194 202* 219 240* 244 240*

3 153 170* 181 202* 208 202* 236 240* 264 285*

4 160 170* 191 202* 222 240* 253 285* 284 285*

* standard letter heights of Danish road standards** number of standard informations

Requirements for letter heights – good quality of letters

Driving speed

50 km/h 70 km/h 90 km/h 110 km/h 130 km/h

n ** letter height (capitals)

1 206 202* 238 240* 271 285* 303 340* 336 340*

2 217 240* 254 285* 291 285* 328 340* 366 405*

3 229 240* 271 285* 313 340* 354 405* 396 405*

4 241 240* 287 285* 333 340* 379 405* 426 405*

* standard letter heights of Danish road standards** number of standard informations

Requirements for letter heights – poor quality of letters

Requirements for visual performance:- Retroreflective signs shall comply with requirements for fixed signs- Luminous signs shall comply with classes and requirements of EN 12966-1 !?

Danish technical handbook for VMS

Classes and requirements of EN 12966-1

Characteristic Classes Remarks

colour of emitted light C1, C2 C2 is the more restrictive

luminance of sign face L1, L2, L3 *) L3 has the highest luminance

contrast R1, R2, R3 R3 has the highest contrast

beam width B1, B2, B3, B4, B5, B6, B7

B7 has the widest beam

*) some additional classes apply for tunnels and specific situations

Classes:

Requirements: uniformity, no flicker

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

X

Y

white

red

blue

green

yellow

C1 colours

White is permissive, but does not allow yellow LED’s

Luminance class L3 is preferred, but L2 is accepted

(based on some small studies)

Contrast class R2 is accepted

(no studies)

R1 R2 R3

B1

B2

B6

B7

B4

5

7

10

15

30

B3 10

B5 15

-5-10

-20

vertical plane:

horizontal plane:

Beam width class B4 is normally preferred (depends on the situation)

class B4

Additional requirements for visual performance

Danish technical handbook for VMS

Illuminance on sign face

Colour of field on sign face

white white/yellow

yellow green red blue

40 000 lx 62 200 52 700 37 200 18 600 15 500 6 200

4 000 lx 11 000 9 350 6 600 3 300 2 750 1 100

400 lx 3 000 2 550 1 800 900 750 300

40 lx 1 250 1 065 750 375 315 125

4 lx 375 320 225 115 95 37,5

Maximum permissible luminances (all luminance classes)

Those at 40 000 lx are too high(eye damage)

--------- -------- -------- -------- -------- ------- 31 100 26 350 18 600 9 300 7 750 3 100

Danish handbook: reduction to 50%

Illuminance on sign face

Colour of field on sign face

white white/yellow

yellow green red blue

40 000 lx 6 200 5 270 3 720 1 860 1 500 620

4 000 lx 1 100 935 660 330 275 110

400 lx 300 255 180 90 75 30

40 lx 200 170 120 60 50 20

4 lx 60 51 36 18 7,5 6,0

Minimum luminances (luminance class L2)Standard; a luminance controlis implied, but not secured

Danish handbook; requirements for: - detector (directional and spectral) - luminance - illuminance function

Illuminance on sign face

Colour of field on sign face

white white/yellow

yellow green red blue

40 000 lx 6 200 5 270 3 720 1 860 1 500 620

4 000 lx 1 100 935 660 330 275 110

400 lx 300 255 180 90 75 30

40 lx 200 170 120 60 50 20

4 lx 60 51 36 18 7,5 6,0

Minimum luminances(luminance class L2)

Standard; a balance between colours is implied, but not secured (for instance maximum red is higher than minimum white)

Danish handbook; requirements are added

Handbook Requirements:

No disturbing luminance variations

No visible changes between luminance steps more often than 5 seconds

Physical requirements:

- VMS shall comply with classes and requirements of EN 12966-1

Danish technical handbook for VMS

Parameters Class designation Remarks

Temperature T1, T2, T3

Pollution D1, D2, D3, D4 D4 is the more restrictive

Protection P1, P2, P3 P3 is the more restrictive

*) a classification of IP classes ? (IP45, IP55 and IP66)

*)

Classes and requirements of EN 12966-1

Classes:

Requirements: Resistance to loads, impact resistance, vibration resistance, nominal voltage, mains frequency, power up activation, switch off voltage response, voltage interruption, temporary overvoltage, electrical safety and electromagnetic compatibility

Temperature: T2 is preferred (-15 to +55 C) Pollution: D class (conductivity caused by dust, condensation, rain and snow) ?Protection: minimum IP 55

Other requirements

Danish technical handbook for VMS

Messages:when the sign is not in use (black)when there is a failure (out of order)

Change over time:

Control and monitoring (e.g. logging)

fastmediumslow

t 1 seconds1 < t 3 seconds3 < t 10 seconds

Thank you for your attention

Danish technical handbook for VMS