Skip to main content
Menu

Fast facts

Why upgrade the Britannia roundabout?

The Britannia Intersection is located on the eastern boundary of the City of Adelaide and is the intersection of five urban roads; Dequetteville Terrace, Kensington Road, Wakefield Road and Fullarton Road (north and south).  This intersection lies on the main entry / exit path into the City of Adelaide from the eastern suburbs and is on the principal inner suburb ring route around the city.  

This busy intersection is identified as a Strategic Route, a primary Freight Route, a primary Commuter Route and a secondary cycle route.

It is currently the worst unsignalised intersection within South Australia when ranked against crash statistics over the past five years. Between 2007 and 2011 a total of 289 crashes were reported at this location, including 51 casualty crashes.

The majority of crashes occur at the Wakefield Road / Dequetteville Terrace junction and at Kensington Road approach.  The improvements to the Britannia roundabout will reduce the number of crashes at this intersection, particularly at these two locations.

The new intersection will be easier to negotiate, with clear signage and pavement marking that enables people to get into the correct lane before they enter the intersection.  Improved lighting will also be installed as part of the upgrade.

What does the upgrade involve?

The primary purpose of this upgrade is to improve safety, and involves:

  • converting the existing roundabout from a five leg roundabout to a four leg roundabout
  • replacing the existing give way triangle at the intersection of Wakefield Street and Dequetteville Terrace with a  three leg roundabout
  • installing a third lane in the roundabout from Dequetteville Terrace to Kensington Road heading south
  • installing appropriate advanced directional gantry signage on all five approaches to the intersection to enable vehicles to position themselves in the correct lane prior to entering the roundabout
  • improved on road direction arrows
  • improved lighting.

Essentially the existing complex five leg roundabout will convert into a standard four leg roundabout and with the smaller one a three leg roundabout.  This will operate like two separate intersections.  These modifications will help decrease speeds through the intersection and provide more time and space for vehicles to move through the intersection.

Standard three and four leg roundabouts are common throughout Adelaide and this by its nature translates to understanding within the community.  See following layout.

What are the safety improvements?

The improvements will reduce total crashes by up to 29% and reduce casualty crashes by up to 23%. 

The majority of crashes occur at the Wakefield Road / Dequetteville Terrace junction and at Kensington Road approach.  The improvements to the Britannia roundabout will reduce the number of crashes at this intersection, particularly at these two locations. The improvements will reduce the incidence of right-angle, rear-end and side-swipe crashes.

The new intersection will be easier to negotiate, with clear signage and pavement marking that enables people to get into the correct lane before they enter the intersection. Improved lighting will also be installed as part of the upgrade.

Will the new intersection make traffic flow more efficiently?

This upgrade is aimed at improving safety at the intersection.  However an improvement in afternoon peak efficiency is expected.  The current intersection takes an average of 78 seconds to travel through in the afternoon peak.  It will take an average of 38 seconds to travel through the upgraded intersection in the afternoon peak period. 

This project maintains the existing level of service in terms of efficiency in the morning peak. There is a 10%-15% increase in efficiency in the afternoon peak.

How do I know which lane I should be in?

This project includes the installation of improved advanced directional gantry signage on all five approaches to the intersection.  This will enable vehicles to position themselves in the correct lane prior to entering the roundabout.  Direction arrows will also be painted on the road in the lanes, further helping motorists to determine which lane they need to be in.

Are dual roundabouts used at other locations?

Dual roundabouts are not a new treatment in Australia.  Examples of dual roundabouts can be found in Naracoorte in South Australia, Sorrento and Perth in Western Australia, and also at places overseas.

Are there any improvements for pedestrian or cyclist access?

The reduced speed of vehicles through the intersection will create a safer pedestrian environment.

Currently there is no dedicated cyclist facility through the existing roundabout.  Cyclist improvements are not included in the upgrade due to the necessity of keeping the footprint of the intersection to a minimum, reducing the impact on adjacent land.

However DPTI is proposing a number of improvements to make alternative routes more attractive for cycling.

  • Installation of centre median refuges at the junction of Dequetteville Terrace / Angas Street and Angas Street / Fullarton Road / William Street, Kent Town. 
  • Installation of a “Green Bike Box” at the intersection of Grant Avenue and Fullarton Road signalised intersection. Grant Avenue is a currently a popular bike route for cyclists entering the city through the Victoria Park.

The centre median refuges are expected to be completed in June 2013 and the bike box by the end of December 2013.

These improvements are intended to provide continuous cycling routes that link local streets and shared use paths through the Adelaide Park Lands into the city.

Providing more attractive cycling facilities will help achieve a key target in South Australia’s Strategic Plan, which is to double the number of people cycling in the state by 2020.

For more information about the Arterial Road Bicycle Crossings project visit: http://dpti.sa.gov.au/cycling/arterial_road_cycling_projects/new_arterial_roads_bicycle_crossings

For further information on Green Bike Box treatments  visit: http://www.adelaidecitycouncil.com/assets/images/Bike_Box_Etiquette_+_bike_signal_lanterns.pdf

Continuous bicycle lanes on the Parade or Kensington Road require extensive parking removal. As an alternative, the department is looking at improving low-traffic BikeDirect routes in the Eastern suburbs to complement Greenways that follow rail corridors in other parts of the metropolitan area.

Angas Street connects to paths in the Adelaide Parklands. William Street and Angas Street are already well-used by cyclists.
These improvements are expected to be completed by end of June 2013.

Another Bike project proposed on Fullarton Road (south) is to install a “bike box” at Grant Avenue lights.  Cyclists enter the greened bike box from the bike lane and move to the left to turn left, right to turn right, or to the centre to continue straight ahead. Drivers of motor vehicles must stop behind the bike box.

There are many examples within the Adelaide City Council area i.e. Pultnery Street, King Wiliam/Pirie Streets. 

Bike Direct route map  

Why aren’t traffic signals being installed?

There are a number of important reasons why we are installing a roundabout instead of traffic signals.

The roundabout option is a better ‘value for money’ solution, and costs much less than installing traffic signals.  Traffic signals would increase delays and queues during peak hours whereas the roundabout allows continuous movement of traffic in a safe and lower speed environment. 

A scheme that involves traffic signals would need to be designed to Australian Standards and would also require a larger footprint.  That means that more land would be required, including land from the Park Lands and also private land would need to be acquired.  Significant trees would also need to be removed.  

The roundabout option will reduce approach speeds, whereas a traffic signal option may increase the severity of crashes due to higher speed involved in rear-end and right angle type crashes. 

How will traffic be managed during construction works?

Construction will start later this year and will be programmed to minimise impacts to traffic during peak hours.