Final Engineering services report _62 Lake Macdonald Drive · OPW25/0057

traffic island with a cut-through pedestrian crossing on the western leg and a painted chevron median to the eastern
leg in accordance with Noosa Shire Council specifications and standard drawings.




Figure 3: Channelised right-turn treatment with a short turn slot [CHR(S)]
(Image courtesy of Guide to Road Design Part 4A)

A sight distance analysis has been prepared, based on the proposed geometry of the upgraded intersection. The
following parameters have been used to determine the minimum Safe Intersection Sight Distance (SISD) in accordance
with Austroads Part 4A (Normal Design Domain):

•     Lake Macdonald Drive (LMD) design speed of 70 km/h
•     General minimum reaction time (Rt) of 2 seconds
•     LMD Eastbound downgrade correction of + 7 m
•     LMD Westbound downgrade correction of + 11 m

Table 1 and Figure 4 provides results of the sight distance analysis which indicates that compliance has been met or
exceeded.
Table 1: SISD Analysis
       Direction              SISD            Grade Correction    SISD Corrected   SISD Achieved    Compliance
     LMD Eastbound           151 m                 +7m                158 m            212 m            Y
    LMD Westbound            151 m                + 11 m              162 m            375 m            Y




Figure 4: Lake Macdonald Drive / Dianella Court Intersection Sight Distances
(Image courtesy of Nearmap.com)




62 Lake Macdonald Drive, Cooroy – Engineering Services Report                                               Page 5
233467 | M24-1037Rpt – Issue A – April 2025