Occasionally traffic signals can fail, resulting in flashing yellow lights or signals being blacked out completely, such as when the power supply is disrupted. Where traffic signals at an intersection are blacked out Australian Road Rule 63 applies. This rule specifies that road users treat blacked out signals at an intersection in one of two ways:
- Where a red traffic light Stop sign is installed rule 67 applies (as if at an intersection with a Stop sign and no traffic lights)
- Where a traffic light Stop sign is not installed rule 72 (for cross streets) or 73 (for T intersections) applies
These rules are normally sufficient for an intersection to operate safely until normal signal operation is restored. In some circumstances police will be notified to perform point duty, and for certain complex intersections, emergency power will be supplied.
Special arrangements for complex intersections
There are currently 83 intersections in NSW where, because of their geometry, complexity or topography, police cannot carry out point duty effectively. Examples are Five Ways at Miranda, Mona Vale, the Pacific Hwy at Gordon, and the Fish Markets in Sydney. To prevent road user safety from being compromised Roads and Maritime Services uses portable generators that can provide emergency power at up to twenty of these critical intersections concurrently. The generators would be used when a power outage is expected to last 2 hours or more.
Roads and Maritime Services ’s Transport Management Centre will normally arrange for emergency power to be provided to these particular intersections when required. However, there may be times when other incidents on the network will take priority, and the operation of the intersection will return to normal only once the main power supply is restored.