On the 14th of October the Study tour visited the office of Arcadis in Sydney. At the office the participants received an informative presentation about the Warringah freeway upgrade which is at the time of writing in its construction phase in northern Sydney. After the general briefing about the project the second part of the excursion to Arcadis consisted of a short walking tour along multiple project sites of the Warringah freeway upgrade. This was an insightful tour which helped participants put the information from the presentation into a real world (pacific) perspective.
As mentioned the first part of the excursion was a project briefing which was given by Christine from Arcadis. She studied civil engineering and now works for Arcadis on the design side of projects. For the Warringah Freeway upgrade, Arcadis was hired to make the design. This was done together with designers from Jacobs Engineering Group. Therefore, Tom from Jacobs Engineering Group was also present to explain some details about the project and answer questions from the participants. Tom also studied civil engineering. Seeing as both our presenters had a civil engineering background they were able to answer our specific questions related to some of the micro studies, in particular sustainable transport and …
The original Warringah freeway was built in the 1940s as a connection from the city centre to north Sydney where a lot of residential area was located. Over the years this suburban area has expanded, increasing the traffic flow towards the city to 165,000 vehicles and 79,000 bus passengers each day across the Sydney Harbour Bridge. The Warringah Freeway is well over its intended design capacity as a result of the explosive growth of North Sydney of the last decades. The upgrade of the Warringah freeway aims to decrease the load on this icon traffic artery.The Warringah freeway is part of the Sydney Orbit (figure 1), mainly aiming to connect surrounding suburbs with the central business district. The road is also a set up for a new tunnel, namely the Western Harbour tunnel. This tunnel will link with the Warringah freeway north of the harbour bridge and subsequently decrease the traffic load of the bridge.
The original name of the project was: Western harbour tunnel, beaches link tunnel highway upgrade. However, as the beaches link tunnel was scrapped by the government and made a separate project, the name is now the Warringah freeway upgrade. The budget for this project is approximately 1.3 billion Australian Dollars, which is actually relatively low compared to other infrastructure projects in Sydney, such as the aforementioned Western Harbour Tunnel. Placing the freeway underground was not believed to be a viable option, as the underground situation at the project site is very complex, with lots of old cables and pipelines. This would make it close to impossible to find the space for a tunnel system large enough to fit all of the traffic that the Warringah freeway has to accommodate.
The work on the project is going on non-stop, so no weekends, or holidays such as Christmas break. Consequently, there is noise nuisance during the night for surrounding residents. During construction 3 noisy nights every 2 weeks is the maximum nuisance allowed as dictated by the government. So the more quiet work is scheduled during the evenings. Once the construction works are completed the noisewalls along the freeways will be improved to deal with the increased noise from the additional freeway lanes.
Next to noise, there was also a concern about the environment for which the government stated some clear rules that must be followed in the design. For the Upgrade of the Warringah freeway, a lot of trees had to be removed, which raised some alarms from local stakeholders.. The government required that for every tree cut down 2 new ones need to be placed, within the project boundaries. Next to trees, also a couple houses needed to be demolished as the government chose the almost straight path (since demolishing houses was unavoidable). These residents were fairly compensated and their land was bought by the state.
Naturally, the freeway upgrade is a project predominantly aimed at motor traffic. There will however be dedicated lanes for active modes of transport, namely for pedestrians and cyclists. It is hoped that this will stimulate the use of alternative modes of transport to decrease the reliability of motor traffic in Sydney partly.
The project takes future increases in traffic into consideration, using models that predict traffic up to twenty years into the future. This will help ensure the project will not be obsolete within the coming years.
The project is split in 3 zones, south, central and North. Each is about 10 kilometres long. Multiple bridges had to be upgraded or newly built in these 3 zones. All new pedestrian bridges are required to have a space for cyclists as well. Of course, also multiple ramps had to be built to connect all the new lanes to the existing network. Some of these ramps are above ground and others go underground so tunnels also needed to be dug. Although this highway section is relatively small there are a lot of crossings. The following six bridges will be constructed across the highway.
– High street bridge, for motorised traffic
– Mount street bridge, for motorised traffic
– Ridge street bridge, for pedestrians and cyclists
– Falcon street bridge, for pedestrians and cyclists
– Miller street, for motorised traffic
– Ernest street bridge, for pedestrian and cyclists. The old bridge in this location will be moved 30 meters to the right. Here its pillars fit with the new number of lanes.
An interesting feature of the bridges is the fact that their girders are bolted together instead of welded together, which is the usual approach. This makes maintenance and eventual replacements easier, as the connections are not as permanent as through welding.
The main goal was a setup for the Western Harbour tunnel. The freeway system is currently a missing link to the west, skipping the central business district area. Congestion reduction in this area is most welcome, but this road is so crowded that it will likely always will be congested.
Construction started 2 years ago in 2022 and was expected at the time to last until 2027. At the time of writing, about 50% of all the construction work is complete, so the project is well on schedule to be finished by the intended deadline.