4895_RAL20-0020Response

RAL20/0020 Reconfiguration of a Lot: Response to Information Request – Report                           6


                2.2 The current formation of the driveways in the road reserves and
                    recommendations for any necessary improvements

                2.3 A conclusion that the driveways, including any necessary improvements
                    are safe and suitable for the intended use.

4.1.2.1 Assessment criteria
As a local distributor road through a Rural zone, Cooroy Belli Creek Rd is considered for the
purposes of this assessment to have a daily traffic volume of less than 4000vpd, with a
maximum posted speed limit of 80km/hr. Traffic counts may be available to confirm traffic
volume.
Noosa Council’s standard drawing RS-056 Driveways – Rural Driveways nominates a Safe
Site Distance (SSD) of 181m for an 80km/h speed limit. Council’s PSP6 Engineering Design
Standards (Schedule 6.7 of the Noosa Plan 2020) state the driver’s point of reference for
determining SSD as “…seated in a standard vehicle at the entrance to the
road carriageway with the vehicle 30 millimetres (sic) in distance back from the edge of the
shoulder...”
The vehicle setback of 30mm is incorrect: the previous edition of Council’s standards PSP5
Engineering Design Standards more accurately interprets AUSTROADS Guide to Road to
Design (AGRD) to require SSD to be measured “…with the front of the vehicle 0.3m clear of
the edge of the bitumen…”.
Council’s Rural Driveways standard drawing which is the reference for compliance does not
describe the driver’s point of reference in either of these terms; however, it is consistent with
the current Austroads requirements for Safe Intersection Sight Distance (SISD) as follows:
        Designers should note that SISD….
        assumes the driver on the minor road is situated at 7.0m (minimum of 5.0 m) from
        the conflict point on the major road. SISD allows for a 3 sec observation time for a
        driver on the priority legs of the intersection to detect a problem ahead (e.g. car from
        minor road stalling in through lane), plus the SSD.

Driver’s point of reference is also described in the below SSD diagram in terms of a 5m (3m
min.) distance from the edge line. This definition is adopted for measuring SSD for the existing
driveways. SISD is measured from a 1.1m of a driver’s eye height to 1.25m top of the
oncoming vehicle.




Figure 3: Extract from Department of Main Roads 2006 Fig.3.2 showing measurement references for Safe Sight
Distance, reproduced by Austroads 2017.




                                                                                         Long View
                                                                                         Consulting Engineers