Battery powered traffic signals impacted by Stage 4 load-shedding and above

Nearly 75% of signalised intersections on the City of Cape Town’s road network is equipped with Uninterruptable Power Supply (UPS) systems. Unfortunately, the UPS batteries do not have sufficient time to recharge when Eskom implements Stage 4 load-shedding or above, as is currently the case.

The City’s Urban Mobility Directorate has, over the years, invested significantly in the acquisition and implementation of Uninterruptable Power Supply (UPS) systems at signalised intersections on our road network to protect road users as much as possible from the impact of load-shedding.

A total of 1 228 of the City’s 1 652 traffic signals are equipped with UPSs that are charged from mains power, and then power the signal when load-shedding is implemented.

This means nearly 75% of signalised intersections across the whole city, regardless of whether it is within a City or Eskom supply area, can maintain operations during load-shedding up to Stage 3. In so doing, we can ensure traffic flow, mitigate congestion, and importantly, prevent road users from unnecessary stops at crime hotspots.

The directorate undertakes continuous maintenance and replacement of our existing UPSs because of unit age, failures or vandalism and theft.

‘We have replaced and repaired units at 120 signalised intersections in the past month. Unfortunately, when Eskom implements Stage 4 load-shedding or above, the UPS batteries do not have sufficient time to recharge. This means that the batteries do not have enough stored power to keep the traffic signals operating throughout the next outage. We are busy upgrading our UPS systems with lithium battery technology to decrease the time they need to recharge, but an upgrade of all of the intersections across the road network is very expensive and will take a number of years to implement.

‘The City tries its utmost to limit the impact of load-shedding as far as it is within our control. Continuous interruptions in power supply shortens the lifespan of our infrastructure, and more importantly, it has a severe impact on residents’ commuting time. This is exacerbated by the theft and vandalism of the UPS systems by criminals who have no regard for their communities. To counter this phenomenon, we are now testing a pilot initiative where we bury these systems and our traffic signal equipment in underground safety chambers, as opposed to above ground where the equipment is an easy target. It sounds like something from a sci-fi movie, but this is how far we now have to go to protect our infrastructure.

‘I am pleading with residents to report incidents of vandalism and theft to the South African Police Service, or to our Transport Information Centre. Vandalism is not a victimless crime. Defective and damaged traffic signals add to the risk of collisions, potentially life-threatening delays for emergency vehicles and contribute to the frustrations experienced by commuters in grid-lock traffic,’ said the City’s Mayoral Committee Member for Urban Mobility, Councillor Rob Quintas.

Road users are reminded to treat intersections as four-way stops when the signals are out. Please also report continuous outages to our Transport Information Centre so that we can repair these as soon as possible.

Residents can contact the TIC on 0800 65 64 63; the TIC is available 24/7 for all transport related inquiries and incident reporting.

Source: City Of Cape Town

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