RFI - 20210153 Maple St Traffic Assessment

Where, DT= 5.0 seconds (3 second observation time + 2 second reaction time)
           d= 0.36

           a = 5% (NE – SW), -5% (SW – NE)
The area of Maple Street within which the site is located is within a 40km/h speed limit area. A review of Noosa
Council traffic counts has identified that a 2002 count collected in a location 100m south of Myall Street (asset id:
0007511) is the closest count available to the proposed driveway access to assess the 85th percentile speed. Over
the week of data collection, the 85th percentile speed in this location was 46.1km/h which is considered suitably
representative of the expected conditions. The most recent traffic count in the dataset at #72 Maple Street (2017)
gives an ADT of 2587 vehicles.

The desirable NDD SISD for the driveway access is therefore:

     -     91m for vehicles travelling from SW to NE, and

     -     84m for vehicles travelling from NE to SW

In accordance with AGRD4A 3.4, the EDD criteria set the minimum limits for SISD. In accordance with AGRD4A
Appendix A.2, the observation time for the EDD criteria is reduced to 1.5 seconds and d is increased to 0.46 under
the site conditions. The minimum EDD SISD for the access is therefore:

     -     65m for vehicles travelling from SW to NE, and

     -     61m for vehicles travelling from NE to SW


     4.2. Minimum Gap Sight Distance (MGSD)
The MGSD represents the critical acceptance gap distance that allows vehicles to enter or cross traffic from an
intersection. The sight distance is captured representing the line of sight from the eye level of the driver
approaching the conflict point (1.1m) to an object at 0.65m on the travelled road representing a car’s indicator as
shown below in Figure 4-3.




Figure 4-3 – MGSD for right and left turning vehicles



For both left turn and right turn movements across a two lane road, AGRD4A Table 3.5 gives a critical acceptance
gap of 5 seconds. Table 3.6 of AGRD4A relates the critical acceptance gap to the 85 th percentile speed of
approaching vehicles. Interpolating the given values for a 46km/h approach speed, the minimum gap sight
distance is determined to be 63m in both directions.


     4.3. Sight Distance Assessment
Using LIDAR topography (Noosa-Gympie 2015 Project) of the region, an assessment of the proposed access has
been carried out against these sight distance requirements.




Project number 20210153                                                                                         Page 10 of 20
File 20210153 Maple St Traffic Assessment Report.docx, 2023-05-04 Revision 0

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