Appendix C: Technical and installation information on active signs

Active warning signs (at schools)

Refer also to the Speed management guide

Sign specification

Active – flashing light (with reflective symbol and text)
(minimum size as specified for sign W19-2.2 symbolic warning - active flashing light (with symbol W16-4 Children))

Active – LED (light emitting diodes)
(minimum size as specified for sign W19-2.1 symbolic warning - Active – LED (with symbol W16-4 Children))

Flashing light specifications

The lights should:

• be placed in the top left-hand and right-hand corners of the sign;
• be coloured orange;
• be at least 60 square centimetres each in area;
• be set to flash alternately at a rate of 1 hertz; and
• have cowls installed if sun strike is likely to be an issue.

There may be a need to have an indicator light that can be seen from the rear of the sign from the school or crossing point to indicate when the lights are operating.

Power supply

Options to be considered for supplying power to the active sign units include:

• solar power (which worked well within the trial process) and is generally most suitable for rural areas;
• linking the battery for the sign to an adjacent street light; and
• linking the battery for the sign to a nearby power supply.

Installation of the signs

Signs can be attached to power poles so the units have a solid base. Where new support structures have to be erected they should be at least 100mm diameter with a foundation design that will prevent twisting yet remain frangible. They should be mounted high enough to provide a suitable clearance above the footpath or ground so they are less likely to be tampered with. The recommended clearance above footpaths it 2.5m. However, if the support pole is located close to the kerb where large vehicles (such as buses) are likely to stop, then a higher mounting height of 4.4m or more may be needed so that the sign is not damaged by high vehicles.

Signs should be placed so the driver’s view of them is not obscured by vegetation. If necessary, trees located near the roadway should be pruned regularly to maintain the effectiveness of these signs. At some sites where there is a special need to highlight the presence of the school to drivers, a duplicate active school zone warning sign can be placed on the right-hand side of the road or on a solid median.

Activation of the lights and LED displays

There are different types of activation systems depending on the sign type and operation. These include:

• automatic activation by wireless control. An antenna is placed on the outside of the school building and connected to the control box. Ideally there should be a direct line of sight from the antenna to the receivers (located on the signs) - while this is more effective, it may not be essential. However, at some sites there could be difficulty obtaining reception for the units and care will be needed to place them so this can be achieved. Checks should be made for possible interference from other nearby electronic equipment;
• manual activation by hand held remote control units; and
• activation from a control box by wired connection direct to the signs.

The control box or activation unit should be located at a secure place within the school grounds where only authorised personnel can have access to it.

Programming systems

The programming system needs to allow for any variations to normal school operating hours including holidays and events that may be held at the school outside normal hours. The activation units need to be programmed to allow information to be entered into the system for set school activity times, holidays and daylight saving time changes together with a manual override system to allow for one-off special events.

The times when the signs operate should coincide with the school activity times as agreed in writing by the school and RCA. A time-out facility should be installed so that the signs automatically switch off after a maximum time (possibly 1 hour for normal use and possibly 30 minutes for one-off events) if the unit has not been manually switched off.

The programming system can be completed by installation of specific software. Further information should be obtained from the sign supplier.

Maintenance

It is essential that regular checks are made to ensure the active device is working correctly. The RCA needs to ensure that appropriate inspection and maintenance systems are in place as part of its agreement with those authorised to operate the system. The respective maintenance responsibilities of the RCA and the school should be clearly set out in this written agreement.

Active warning signs (not at schools)

The general approach to the use of active warning signs is set out in the TCD manual Part 1 - General requirements for traffic signs, section 6.2. This reference should be consulted when considering the use and installation of active warning signs.

TCD manual Part 1

Locations of signs in relation to the activity

There are three options which can be considered. An active warning sign can:

• replace a standard reflective-only warning sign at the same position in advance of the hazard as the standard warning sign; or
• be installed as an advance warning sign before a standard reflective warning sign; or
• replace a standard reflective-only warning sign at the same position in advance of the hazard as the standard warning sign and the standard sign can be shifted to become an advance warning sign.

Duration of active component of sign

Generally the following active components should only be displayed while the hazard exists on or near the roadway:

• flashing orange or yellow lights;
• W1-1 Road works symbol with W1-1.X supplementary text;
• W2-1B Hazard warning symbol with W2-1.X supplementary text;
• W3-2 Slippery surface symbol with W3-2.1 Slippery surface supplementary – ice/grit;
• W4 Lane management symbol with W4-10 Distance ahead supplementary;
• symbolic warning messages; and
• text warning messages.

The RCA should ensure that active components are turned off when the hazard is not present. Additional detection devices may be needed to achieve this.

Sign specifications

W19-1.1 General warning variable

W19-2.1 Symbolic warning - active LED

Note: 700 x 1000mm is the minimum size as specified in the TCD Rule. Larger sizes may be used, particularly where the speed limit is above 50km/h or there is a wide or divided carriageway.

Note: 700 x 900mm is the minimum size as specified in the TCD Rule. Larger sizes may be used, particularly where the speed limit is above 50km/h or there is a wide or divided carriageway.

Flashing light specifications

If installed in the sign, the lights should:

• be placed in the top left and right hand corners of the sign;
• be coloured orange;
• be 60 square centimetres each in area;
• be set to flash alternately at a rate of 1 hertz; and
• have cowls installed if sun strike is likely to be an issue.

Power supply

Options to be considered for supplying power to the active sign units include:

• solar power, which is generally most suitable for rural areas;
• linking the battery for the sign to an adjacent street light circuit; and
• linking the battery for the sign to a nearby power supply.

Installation of the signs

Permanent signs can be attached to power poles so the units have a solid base. Where new support structures have to be erected, they should be at least 100mm diameter with a foundation design that will prevent twisting yet remain frangible. Refer to Specification P24: permanent traffic signs.

Specification P24: permanent traffic signs.

They should be mounted high enough to provide a suitable clearance above the footpath or ground so they are less likely to be tampered with (particularly in urban areas). A clearance of 2.5m above footpaths is recommended. However, if the support pole is located close to the kerb where large vehicles (such as buses) are likely to stop, then a higher mounting height of 4.4m or more may be needed so that the sign is not damaged by high vehicles.

Signs should be placed so the driver’s view of them is not obscured by vegetation. If necessary, trees located near the roadway should be pruned regularly to maintain the effectiveness of these signs.