The information below is intended to reflect the preferred practice of Main Roads Western Australia ("Main Roads"). Main Roads reserves the right to update this information at any time without notice. If you have any questions or comments please contact Dave Landmark by e-mail or on (08) 9323 5441.
To the extent permitted by law, Main Roads, its employees, agents, authors and contributors are not liable for any loss resulting from any action taken or reliance made by you on the information below or changes to its preferred practice.
Main Roads is currently in the project development stage for a Managed Freeways Pilot Project.
The lane to be dropped is an auxiliary lane1
1 An auxiliary lane in the freeway context is a lane that starts at an on-ramp (normally as an added lane) and ends at the adjacent downstream off-ramp (normally as a lane-drop).
The lane to be dropped is not an auxiliary lane
Figure 2.3(a): Example of Inappropriate Exclusive Left Turn Lane
- Amount of flow at each upstream ramp. If any of the upstream ramps has a low flow it is not possible to build a queue and it becomes ineffective as a slave. However, it also means that the low flow may not contribute much traffic to the bottleneck problem
- Amount of storage at each ramp. If any of the upstream ramps has poor storage it cannot provide the assistance needed as a slave in holding back traffic
- May need more ramps to control an 8 lane freeway and less for a two lane freeway
The criteria of 1,800 pc/h/ln for provision of freeway coordinated ramp signals is based on a number of factors including:
Table 6.2 replaces Table 6.2 in the VicRoads document:
Table 6.2: Standard Drawings for Freeway Ramp Signals
Figure 6.12: Typical Freeway Ramp Signals Layout – Freeway to Freeway Ramps
Figure 6.16: Line Marking at the “Edges Meet” Point
Figure 6.17: Freeflow Truck Bypass Lane – Indicative Signs and Line Marking