New section of Sandspruit Bridge almost complete

The new western section of the Sandspruit BridgeThe new western section of the Sandspruit Bridge under construction in October. (CLICK ON IMAGE FOR LARGER VERSION)

With the western section of the new Sandspruit Bridge on Katherine Street in Sandton nearing completion, the Johannesburg Development Agency (JDA) is gearing up for the diversion of traffic onto the new section, the demolition of the old bridge and the start of construction on the eastern section.

The JDA is overseeing construction of the new bridge, which will be both higher than the old bridge - and therefore better protected when the Sandspruit River is in flood - and considerably wider.

Easing congestion, paving the way for BRT

sandspruit google2 300Google Streetview visited the old Sandspruit Bridge just prior to construction in January 2015. (Photo: - CLICK ON IMAGE FOR LARGER VERSION)The old, two lane-bridge is completely unsuited to the volumes of traffic that traverse the Katherine Street stretch between Grayston and Marlboro Drives daily. The new, six-lane bridge will bring an end to traffic bottlenecks at this point, while opening the way for the Rea Vaya bus rapid transit (BRT) route that the JDA is laying down along Katherine Street.

According to Siyabonga Genu, senior development manager at the JDA, the two central lanes of the completed bridge will be reserved for dedicated BRT lanes, leaving four lanes for private vehicles and other modes of public transport.

Genu expects construction of the new western section of the bridge to be completed by 26 November, with diversion of traffic from the old to the new section to follow soon thereafter, paving the way for the demolition of the old bridge and the start of construction of new eastern section.

"The existing bridge will be demolished on 29 November 2015 and construction of the eastern section of the bridge will commence in January 2016."

Complex engineering, careful planning

sandspruit2 300The new Sandspruit Bridge will have 6 lanes, two of which will be reserved for BRT. Construction here under way in November 2015. (CLICK ON IMAGE FOR LARGER VERSION)Genu describes the design, engineering and construction that has gone into the new bridge - as well as the process of transition from the old to the new bridge - as highly complex, requiring careful planning.

Once the old bridge has been demolished, excavations will made to prepare for construction of the substructure for the new eastern deck. First, however, the foundation conditions will be inspected and, if the earth material currently in place is of substandard quality, proper bedding material will be imported and compacted before construction of the new concrete foundation bases gets under way.

Throughout, the contractors will have to take steps to prevent harmful material, both from the demolition of the old structure and construction of the new one, from entering the river.

And afterwards, special mattresses will have to be placed to protect the river inlet area against erosion, and areas of ground will have to be grassed and/or re-grassed where necessary.

Opening up a new Corridor of Freedom

The new Sandspruit Bridge forms part of the phase 1C extension of the Rea Vaya BRT network from Parktown to Alexandra and Sandton. This network will form the backbone of the Louis Botha Avenue Corridor of Freedom between the Joburg CBD, Alexandra, Sandton and suburbs further north.

Dedicated BRT lanes are being constructed to create two new Rea Vaya trunk routes, the first running along Louis Botha Avenue between Parktown and Wynberg, the second crossing the M1 highway - on a new dedicated BRT bridge currently being built between the Grayston and Marlboro interchanges - before turning left into Katherine Drive and proceeding as far as the Gautrain station precinct in Sandton.

Along Katherine Street between Grayston and Marlboro Drives, construction of the central BRT lanes will be accompanied by upgrades to the mixed traffic lanes, traffic signals, sidewalks, street lighting and signage, and in some cases underground services.

Besides construction of the new bridge, the Marlboro onramp onto the M1 north will also be widened to provide three right-turning lanes off Katherine Street.

And the phase 1C expansion as a whole will include the provision of high-quality cycling and pedestrian routes and the integration of Rea Vaya with other modes of public transport. This will include:

  • A new state-of-the-art public transport interchange in Alexandra;
  • A five-kilometre dedicated walking-cycling pathway, incorporating an iconic bridge over the M1, to accommodate the more than 10 000 people who walk between Alexandra and the Sandton CBD every day; and
  • A new transport system in the Sandton CBD that incorporates the Gautrain station, pedestrians and cyclists.

The bulk of this is scheduled to be complete by April 2017, after which Rea Vaya services between Sandton, Alexandra and the CBD will begin, followed by the introduction of Rea Vaya feeder routes to extend the network to Rosebank, Randburg, Greenstone, Ivory Park, Rabie Ridge and Midrand.