3D laser detection system for ‘Bridget’

Bridget the bridge in Atlantic Road, Muizenberg, has earned herself quite a reputation.

Her truck-eating appetite is voracious enough for Transport for Cape Town (TCT), the City of Cape Town’s transport authority, to invest R300 000 in installing a 3D laser detection system in Muizenberg.

The 3D laser detection system is the first to be installed in Cape Town.

It was installed to help prevent trucks with a height of 2.5m and more from crashing into the low railway bridge at Atlantic Road.

These crashes have happened so often that social media sites are flooded with pictures, comments and often, laughter, from residents of Muizenberg each time.

Although it is too early to determine the success rate of the new warning system, it is worth noting that no crashes have occurred since June 1, when the system started operating.

City’s mayoral committee member for transport, Brett Herron said the money was a small price to pay if it could prevent at least half of the crashes that have taken place at the bridge over the years.

The 3D laser detection system is the first to be installed in Cape Town.

Mr Herron said the railway bridge crossing was notorious for crashes, mainly because road users often underestimate the height of their vehicles or load when driving through under the bridge.

“A truck or vehicle crashes into or gets stuck under this bridge about once a week despite the numerous signboards along Main Road and Atlantic Road warning drivers of the 2.5m height restriction ahead,” he said.

He said it became apparent that a different warning system was required to improve the safety of road users and to try to prevent crashes into the railway bridge over Atlantic Road, as the earlier systems were affected by the extremely corrosive environment, and required constant maintenance.

The opportunity to remedy this situation was offered by the recent Main Road rehabilitation project in Muizenberg when it was decided that an improved system could be installed as part of the roadworks.

He said TCT officials proposed a 3D laser detection system, following international research.

“A system developed by a local company was installed above the northbound carriageway of Main Road, about 150m from the intersection with Atlantic Road. It uses an infrared laser beam to read the height of the vehicles and their load. Should it detect that a vehicle in the turning lane is higher than 2.5m from the road surface, a warning system is triggered at the intersection with Atlantic Road.

A signboard with high-power LED lights will flash for about 30 seconds, indicating to the driver that their vehicle is too high to cross underneath the railway bridge,” said Mr Herron.

The plan is to roll out two more laser detection systems – one above the southbound carriageway of Main Road for traffic approaching Atlantic Road from Steenberg, and another above Atlantic Road for traffic approaching the railway bridge from the eastern side along the R310.

“These roll-outs will happen as soon as we have determined the success rate of the first system,’ said Mr Herron.