4895_RAL20-0020Response

RAL20/0020 Reconfiguration of a Lot: Response to Information Request – Report                        11


4.1.2.4 Site access: Lot 49 MCH1168 (existing)

4.1.2.4.1 Sight distances
The property access location for the existing Lot 49 on MCH1168 is proposed to be a shared
crossover for the new Lots 49 and 429. A detailed contour survey was undertaken to provide
for the preliminary design of the proposed driveway and property access for new Lot 429 and
included surveyed measurements of sight distances from a driver reference point at the
proposed property entrance.




Figure 7: Survey extract showing sight distances for existing access point to Lot 49.

    •    Sight distance West to inbound vehicle = 110m, < [SSD = 181m]
    •    Sight distance East to outbound vehicle > SSD = 181m
Sight distance therefore does not comply with the general SSD nominated on the RS-056 for
the inbound lane but complies for the outbound lane.
To check compliance of the inbound lane in accordance with AGRD procedure property
entrances, the following design values are nominated from AGRD Appendix A:

    •    Appendix A 2.4 Observation time (OT) for EDD SISD, T-intersection to single
         carriageway, two-lane, two-way roads with less than 4000vpd = 1.5 seconds
    •    Appendix A 3.4 Driver reaction times (RT) for ‘normal rural driving’ = 2.0 seconds
    •    Coefficient of deceleration (from AGRD Pt.3 Table 5.3):
             o 0.32 (cars braking on 4% downhill, inbound);
             o 0.25 (truck braking on 4% downhill, inbound);
Safe Intersection Sight Distance for the existing property entrance to Lot 49 is calculated from
the AGRD Appendix A 2.5 for the normal case (day).
 EDD SISD                Sight    Norm-day                Norm-night         Mean-day   Mean-night
                         distance (base case)             (check)            (check)    (check)
 Car inbound                      156m                    N.C.               N.C.       N.C.
                         110m
 Truck inbound                    178m                    N.C.               N.C.       N.C.
N.C. = Non-compliant with base case




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