Referenced Document - MCU12/0216

Quarry Rehabilitation
Lake Macdonald Drive, Lake Macdonald

© 2012 - TTM Consulting (SC) Pty Ltd                                        Reference No: 12SCT0037



6.           Lake MacDonald Drive Capacity Review

6.1          Introduction
This Chapter reviews the traffic operation and capacity performance of the Lake MacDonald Drive
corridor and its existing intersections on the proposed haulage route between the existing
Westridge Quarry access and White Pit Quarry access locations.


6.2          Road Corridor Capacity Criteria
The AUSTROADS Guide to Traffic Engineering Practice - Part 2: Roadway Capacity indicates that
two-lane rural highways have a capacity of 2,800 passenger cars per hour total for both directions
of flow, under ideal conditions where there are no restrictive roadway, terrain or traffic
conditions.
However, considering the prevailing roadway and traffic conditions along Lake MacDonald Drive,
it is estimated that the highest total service flow rate (AM Peak) is approximately 200 vehicles per
hour total for both directions of flow based on 2012 traffic levels.
Austroads defines level of service as a qualitative measure describing operational conditions
within a traffic stream. The term Level of Service (LOS) and its characteristics for rural roads is
defined in Table 6.1.

Table 6.1: Two Lane Rural Road Capacity – Rolling Terrain Two-Way Flow

     LOS                                      Description                      Rating

       A                      Free, unrestrictive flow Very good             Very Good
       B               Mostly free flow, few disruptions Very good           Very Good
       C                                  Stable flow Good                     Good
       D               Mostly stable flow, some delays Acceptable           Acceptable
       E                    Congested flow, delays common Bad                   Bad
       F                                   Forced flow Bad                      Bad
Source: Austroads Guide to Traffic Engineering Practice, Part 2



The volume and composition of traffic on a given road determines the level of interaction
between vehicles and is measured as its LOS. LOS decreases with increasing traffic volumes. LOS
A, LOS B, LOS C in a rural context are satisfactory, with a LOS D satisfactory in some
circumstances.
In cases where traffic, terrain or geometric data may not be precisely known, the AUSTROADS
Guide provides planning guidance on maximum AADT values that two-lane, two-way rural roads
can accommodate under various terrain conditions.




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