City's R263 Million Hospital Bend Project Official Opened
"Today is a very special day for the City of Cape Town and our citizens. I am sure that in a few weeks time when the commuting public get used to the new formation of Hospital Bend they would have forgotten the challenges and difficulties we all had to negotiate the old lane formation", said Councillor Elizabeth Thompson, Mayoral Committee Member for Transport, Roads and Major Projects, who officially opened the new interchange on 22 April 2010.
Capetonians have already had a taste of how this new interchange will work, after the De Waal Drive bridge, pre-selection lanes and Anzio Road bridge opened for traffic over the past two weeks. It is expected to take a while for traffic patterns to stabilise as motorists become used to the new situation and decide on new regular routes.
This project, which was completed on time and within its budget of R263 million (excluding VAT), has become one of the City of Cape Town's flagship transport infrastructure projects.
The accommodation of traffic was an all-important planned and designed aspect of the work which determined the sequence of execution, available work areas and methods of construction using overhead gantries. As a result road users experienced very little inconvenience during construction and lanes were only closed or restricted during night time off-peak traffic periods.
"I want to thank the people of Cape Town from the bottom of my heart for their patience and co-operation during the construction period, and let me be quick to add that we can do only so much to make the roads safer; it is ultimately up to driver behaviour to ensure that the roads are made much safer. I thus call on all road users to drive safely and to choose their lanes early and stay in your lane until you negotiate the interchange successfully," said Councillor Thompson.
Planning for the Hospital Bend upgrade commenced in October 2001. An upgrade of this interchange was necessary because it is an important link between the city, airport and residential areas such as the Southern Suburbs and Khayelitsha. It is estimated that over seven thousand (7000) vehicles per hour pass through Hospital Bend during peak hour traffic.
An extensive planning process included detailed traffic studies, evaluation of numerous concepts in and around Hospital Bend and extensive consultation with stakeholders over several years. This resulted in an innovative proposal which maximised the utilisation of the existing infrastructure, with relatively minimal changes to it, and substantial improvements to the traffic capacity and safety of this road section.
This route is the one of the main gateways to Cape Town, situated along the lower slopes of Table Mountain National Park and the approach along Settlers Way is spectacular. Detailed attention was therefore given to the landscaping and the finishes of all elements of the road, to ensure a pleasant driving experience. This includes vegetation, the retaining wall and paving area finishes.
"There was no doubt that the need to do something about the weaving and contribute to both a safer ride as well as easing the congestion was becoming desperate. Tough as it may have been to get it approved and actually happen, I feel vindicated today that we had the political will to do this," said Councillor Thompson.
The construction and related traffic accommodation facilities on one of the busiest roads into Cape Town required detailed planning, and in many instances influenced the design in order to ensure traffic safety and operation during all phases of construction.
The contract included very strict traffic accommodation measures which were implemented with the least possible interference to the travelling public. General feedback during construction confirmed that this was achieved with great success.
The main feature of the upgrade is the utilisation of a Pre-Selection Scheme concept which essentially allows motorists to select their destinations well in advance of the Hospital Bend Interchange, thus minimising weaving actions (which before the improvements totalled about three thousand (3000) per hour!), which was the major cause of traffic congestion on this road.
There were several operational traffic safety problems in the original configuration and the scheme also provided the opportunity to address these. These include an upgraded on-ramp from Anzio Road towards the M3, the inclusion of an emergency stopping and vehicle access lane (combined with the stormwater drainage channel) along the entire length of the road, the improvement of driver sight distances around various bends and an increase of the vertical clearance below the Joyce Newton Thomson bridge carrying Rhodes Drive over Settlers Way.
- Changes made on Hospital Bend:
- Anzio Road bridge
Rhodes Drive (M3) inbound was widened on the left hand side to create an extra lane before its merge with the N2, to serve as a pre-selection lane for traffic heading towards De Waal Drive. A pre-selection lane from the M3 (inbound) to Hospital Bend was also built. This included the widening of the bridge over Settlers Way (N2) and the upgrading of the M3 to N2 outbound loop. An extra lane was also built on the N2 inbound. These pre-selection lanes were partially opened to the public on Saturday 17 April.
The widening of the bridge over Settlers Way proved to be a major challenge for construction teams, due to the geometric alignment and heavy traffic flow over and under the structure. Similar to the Anzio Road Overpass and De Waal Drive Overpass, the centre span of the deck was supported from temporary overhead girders to accommodate unhindered traffic flow during construction.
The N2/M3 inbound carriageway was also widened at the top of Hospital Bend between Eastern Boulevard and Upper De Waal Drive to provide for the inbound pre-selection lanes and to improve sight distance on the inside of the bend.
Motorists travelling from Rhodes Drive towards the city now have the option of selecting the correct lanes before approaching Hospital Bend, which will then take them to their destinations without the need for any further lane changes.
Motorists who wish to travel to De Waal Drive must therefore pre-select the left lanes prior to Hospital Bend and those heading to Eastern Boulevard must pre-select the right-hand lane. Drivers who make an incorrect lane choice before the interchange can still move through the lanes once they are on Hospital Bend travelling uphill, but this will not be desirable for the optimal operation of the interchange.
A major constraint to this part of the upgrade which the contractors were able to overcome was the limited space available to build extra lanes, as the boundary of the Table Mountain National Park is on one side of the road and Groote Schuur Hospital on the other.
The Anzio Road access into the city from Groote Schuur Hospital was provided with a more conventional left hand merge. This included the construction of a sharply curved bridge overpass structure with very complex geometry to lead traffic from Anzio Road into the city. The substructure's foundation rests upon 750mm diameter augered piles. The bridge consists of a four-span post tensioned slab deck that was constructed in three stages. The third span was supported during construction from overhead girders, so as not to disrupt the traffic flow. The Hospital Bend outbound lane to the M3 was widened as a result of the longer merge from the Anzio Road on-ramp to the M3 outbound.
The major change to Hospital Bend outbound was the construction of the new De Waal Drive bridge to create a pre-selection scheme out of the city. This bridge was opened to the public for the first time on 07 April 2010.
The new overpass bridge has a span length of 45m and was constructed in three stages. The complex geometric alignment and very strict requirements ensuring traffic flow is not disrupted resulted in an impressive overhead girder support system for the second span over Eastern Boulevard during construction.
Motorists heading towards Rhodes Drive (M3 outbound) can now use the new bridge and continue to their destination without any further required compulsory lane changes. Those motorists heading towards Settlers Way (N2 outbound) will in turn use the old De Waal Drive bridge and will therefore also have no need for further lane changes.
Other than the new bridges and widened lanes, various improvements have made to the existing roads. Directional signage on Settlers Way, Rhodes Drive, De Waal Drive and Hospital Bend was upgraded to include overhead gantries and ground-mounted signs.
In addition, median barrier walls, guardrails, the provision of new street lighting along the entire section of road, the resurfacing of the existing road, upgrading of the stormwater system as well as landscaping within the road reserve have now been completed.
City of Cape Town
Councillor Elizabeth Thompson
Mayoral Committee Member for Transport
Roads and Major Projects
City of Cape Town
Tel: 021 400 1221
Cell: 072 336 0497