The Bruce Highway Managed Motorways Project involves a suite of smart technologies on the Bruce Highway southbound between Caboolture and the Gateway Motorway to optimise the performance of the highway and maximise its existing capacity during peak periods.
The project aims to manage traffic flow entering the highway at key congestion points to help delay the onset of congestion, reduce ‘stop-start’ travel, improve travel-time reliability, and enhance safety for merging traffic.
The project involves installation of:
- ramp signals and vehicle detection sensors, and construction of additional traffic lanes, on the Dohles Rocks Road, Anzac Avenue, Boundary Road, Deception Bay Road and Uhlmann Road southbound on-ramps to manage the rate at which vehicles merge onto the highway
- below-surface vehicle detection loops on the Bruce Highway to measure and calculate traffic flow, speed and occupancy levels
- 54 variable speed limit signs to display reduced speed limits in response to congestion, incidents or bad weather
- 33 CCTV cameras to monitor the network and adjust ramp signals where necessary to respond to network conditions.
Installation of the ramp signals and electronic communications technology began in April 2014 and was completed in September 2015 The ramp signals started operating on 21 September 2015.
How the technology works
The ramp signals use smart technology to communicate with traffic detectors embedded into the road surface. The sensors detect the speed and volume of highway traffic flow, and then communicate with the signals at various on-ramps to help maximise highway traffic flow.
As traffic conditions approach congestion , the ramp signals communicate with each other and moderate signal timings at ramps across the highway to begin managing the flow of traffic onto the highway at specific locations, thereby keeping the highway flowing at an optimal rate for as long as possible. For example, an on-ramp experiencing large volumes of traffic will communicate with other nearby on-ramps requesting that they change the timing of their signals to reduce the flow of traffic onto the highway. This will allow the busy on-ramp to increase its flow onto the highway. Once it starts to clear, the other nearby ramp signals will automatically adjust to their original settings.
The ramp signals will generally only operate during high-demand periods, such as the morning peak period, when traffic flow on the highway approaches its maximum capacity, or in response to an incident or bad weather. At all other times when there are free-flowing conditions on the highway, the ramp signals will not operate.
Managed Motorway technology has been delivered at various other locations around Queensland including along the Gateway Motorway, Pacific Motorway, Ipswich Motorway and Western Freeway, as well as Clem Jones Tunnel, Legacy Way and Airport Link.
How motorists should respond
As motorists approach the highway on-ramp, they should keep an eye out for illuminated electronic signs warning them that the ramp signals are in operation. If the sign is illuminated, motorists should be prepared to stop at the ramp signals when a red signal is displayed.
As motorists enter the highway on-ramp, they will notice a pair of ramp signals at the entrance to the highway. The signals operate like standard traffic signals with red, yellow and green phases. If the ramp signal is red, motorists will need to come to a complete stop and wait for the signal to turn green before proceeding. When the light turns green, one car in each lane should proceed along the on-ramp and safely merge onto the highway.
Additional traffic lanes have been built at the on-ramps to provide extra storage capacity for vehicles. Motorists are encouraged to use these additional lanes to help traffic flow on the on-ramps and limit queuing. At each green light, 1 car per lane is permitted to proceed. At locations where there are 2 traffic lanes at ramp signals that merge into 1 lane to enter the highway, normal road rules apply.
Variable Speed Limit signs are due to start operating on the Bruce Highway southbound lanes between Uhlmann Road and the Pine River from late February 2016.
The electronic signs are used to display reduced speed limits in response to changing road conditions such as traffic congestion, incidents or bad weather. When no speed reductions are needed, the signs will display the default 100km/h speed limit.
Live traffic conditions will be monitored via CCTV cameras and in-pavement vehicle detectors, and changes to the speed limit will be made as needed. For example, the signs will be used if congestion is approaching, or occurs, during the weekday morning peak period.
If congestion is imminent, the signs will reduce the speed limit to 80km/h. If congestion occurs and vehicle speeds drop to below 80km/h, the signs will reduce the speed limit to 60km/h. The speed limit will be reduced in 20km/h increments to slow vehicles down safely in advance of congestion.
The variable speed limit signs will aim to improve safety and reduce the crash risk on the Bruce Highway. By adjusting the speed limit to suit the road conditions, this will encourage motorists to drive at speeds appropriate to the conditions.
For the first several weeks, the signs will display the default speed of 100km/h to allow the system to be assessed. After this, the signs will begin full operations.
Work at the Dohles Rocks Road on-ramp was completed in mid-December. The work involved reconfiguring the ramp to extend the far left storage lane back to the left-turn lane at Dohles Rocks Road. There is now a dedicated lane for left-turning vehicles all the way to the ramp signals, and 2 separate lanes for right-turning vehicles from Dohles Rocks Road.
Since the work was completed, there has been significantly better use of all lanes on the ramp. Combined with the additional storage area for vehicles, this has helped to store a greater number of vehicles on the ramp to further reduce the impacts to existing queueing issues along Dohles Rocks Road.
Transport and Main Roads will continue to work with Moreton Bay Regional Council to investigate further upgrades to the local council-controlled network to help address local traffic issues with gaining access to the ramp signals.
Following the initial settling in period, the ramp signal system is now operating as expected at this stage of the project. The system is having a positive impact on Bruce Highway traffic by assisting in delaying the onset of congestion, and helping the highway to recover more quickly when congestion does occur.
Traffic volumes are expected to be lower over the Christmas break, and Transport and Main Roads will be closely monitoring conditions in the New Year in preparation for the return of school in late January 2016.
Since the ramp signals started operating on 21 September, a series of refinements have been made. This period of testing and fine-tuning was a planned and necessary step in the process to properly establish the system. The ramp signal system is now performing as it should be at this early stage of the project.
Since the ramp signals started operating, observations have shown they are helping to delay the breakdown of traffic flow and the onset of congestion, and helping the highway to recover more quickly when these conditions occur.
The ramp signals are proving effective in minimising the breakdown of traffic flow on the Bruce Highway, until such time that congestion from the Gateway Motorway and Gympie Arterial Road inhibits traffic flow on the highway.
At the on-ramps, queues at the Anzac Avenue, Boundary Road, Deception Bay Road and Uhlmann Road ramps are generally being managed within the available ramp storage, with no impacts on intersecting arterial roads.
At the Dohles Rocks Road on-ramp, there were some above-expected delays at the start of ramp signalling. An increased focus was placed on Dohles Rocks Road and the queues were subsequently considerably reduced.
The major issues contributing to queuing on Dohles Rocks Road are the pre-existing capacity challenges along the road, and congestion from the Gateway Motorway and Gympie Arterial Road restricting traffic flow from the ramp onto the highway.
One issue has been an under-utilisation of the extra storage lanes that have been built on the Dohles Rocks Road on-ramp. This has resulted in the full capacity of the on-ramp not being used, and has contributed to some additional queuing (above normal conditions) on Dohles Rocks Road. A mobile Variable Message Sign has been relocated at the on-ramp to encourage motorists to use all lanes.
Transport and Main Roads is dedicated to achieving the best network balance to improving traffic on the Bruce Highway, and reducing delays as much as possible at the on-ramps. It will take several months of fine-tuning the system, and for travel patterns to stabilise, before the full benefits of the system are realised. In the meantime, Transport and Main Roads thanks motorists for their patience.
On 21 September 2015, the ramp signals started operating on the Bruce Highway southbound lanes. During these early days, the system is undergoing a period of fine-tuning and testing. Transport and Main Roads is closely monitoring traffic on the highway and at on-ramps, and making ongoing adjustments to the timing and coordination of the ramp signals to endeavour to delay the onset of congestion on the highway, and limit queuing at the on-ramps.
On the first day of the ramp signal operations, there was congestion experienced at the Dohles Rocks Road and Anzac Avenue on-ramps. A contributing factor to this congestion was an under-utilisation of the extra lanes that have been built on the on-ramps to provide more storage space for vehicles.
Many motorists are not using these extra lanes, which is contributing to queuing at the ramps. Transport and Main Roads is encouraging motorists to use these extra lanes, and this will help to improve traffic flow onto the highway.
Transport and Main Roads has made some modifications to the system and there has subsequently been reduced queuing at the on-ramps. Transport and Main Roads will continue to closely monitor the system and make further changes to improve traffic flow and limit queuing wherever possible.
Transport and Main Roads apologies for any extended delays that motorists have experienced at the on-ramps, and thanks them for their patience during this early phase of the project.