Part 9: Level crossings

Last updated: December 2008. This document ceases to be a controlled document when printed. Please refer to the current version at www.landtransport.govt.nz

6  Control devices

6.3  Railway-activated control devices

Railway-activated control devices at level crossings are described below. These control devices are activated through signalling circuits upon the approach of a train to a level crossing. The activation of these circuits has three basic mechanisms – distance, predictor and manual.

The majority are set to operate a predetermined distance along the railway to give a minimum alarm warning time period before a train operating at the fastest speed permitted reaches the level crossing. In some instances, the warning time may be increased further by multiple railway lines or nearby stations. When HABs are installed, the barriers may be held down for a second train if there would not be sufficient time for the barriers to rise and fall again before the second train would reach the level crossing.

Where stations are located near level crossings, additional equipment may be installed to adjust the warning time to account for a stopping or non-stopping train.

Predictor mechanisms operate control devices by determining the approaching train speed and adjusting the activation of the level crossing so that the length of time between activation and the train reaching the level crossing is constant for all train speeds.

Use of road traffic signals as level crossing control devices may be considered only where:

• the level crossing is extremely close to an existing road intersection that must be controlled by traffic signals
• the maximum rail speed is 15 km/h and it is feasible for rail movements to be stopped before crossing the road
• the installation of standard FLB controls is not feasible due to:
  • space constraints
  • insufficient railway traffic to justify the installation of FLBs.

In these cases, the rail movement cedes the right-of-way. The approach of a train or operation of a manual signalling device by a rail participant initiates a ‘rail’ phase. The rail movement may not proceed until the appropriate ‘T’ aspect is displayed. Sufficient WX6 signs should be mounted on traffic signal poles so that a sign is clearly visible to drivers from all road approach directions.

The automatic alarms at a manually controlled crossing are started by the railway operator before the train crosses the road. In such cases, the rail speed will normally be no greater than 25 km/h so the train can, if necessary, be stopped before crossing the road. There will be no fixed time between the start of the alarms and the train entering the crossing but the rail operator would normally wait until any approaching road traffic has stopped before proceeding.

Where there is a high degree of pedestrian and commuter train traffic on two or more railway lines, additional warning devices may be installed. These may include a secondary audible alarm of a different volume and frequency to the standard level crossing alarms. In addition, an electronic sign warning of a ‘second train coming’ may be installed for pedestrians.

6.3.1  Flashing lights and bells (FLBs)

An FLB consists of two red traffic signals mounted horizontally on a red and white striped pole. The pole may also support traffic signs (see section 4.3.9) and a warning bell, which is intended to alert pedestrians and cyclists to the impending passage of a train. The assembly can be used by itself on the left side of the carriageway, or may be duplicated or triplicated for multiple approach angles, multiple traffic lanes or high traffic volumes (with a potential for overtaking).

When activated, the lights flash alternately and the warning bells ring. When flashing, this signal indicates that drivers must stop before entering the controlled area of the level crossing (defined by the limit lines) and remain stationary during the flashing period.

In some urban situations, the bells (primarily intended as a warning to pedestrian and cycle traffic) may not be activated during normal sleeping hours. In these circumstances, a ‘Bells Off’ (AX11) sign, described in section 4.3.6, must be installed and the sign must indicate the times during which the bells will be switched off.

At level crossings where HABs (refer to section 6.3.2) are installed, bells will always operate until the barrier arms reach the lowered position.

Pedestrian level crossings may be solely protected by bells mounted on a pole. In these cases, a ‘Look For Trains’ (WX8) sign must be placed on the signal pole facing approaching pedestrians and the railway lines must be clearly visible in each direction.

6.3.2  Half-arm barriers (HABs)

In some situations, HABs are used in conjunction with FLB controls.

Barriers are lowered a minimum period (usually 5 seconds) after the lights and bells have been activated. Vehicles on the level crossing can exit the level crossing control area because the barriers obstruct only half the carriageway. Barriers are intended to enforce compliance with flashing lights and reinforce the warning system by providing a physical boundary to access on to the railway.

6.3.3  Pedestrian gates

Where pedestrian and train movements are high, automatically activated pedestrian gates may be justified. These provide positive control of pedestrian movements and also provide good levels of pedestrian (and cycle) service across the railway line/s when the gates are open.

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