4895_RAL20-0020Response

RAL20/0020 Reconfiguration of a Lot: Response to Information Request – Report                 8


    •    Sight distance West to inbound vehicle = 133m, < [SSD = 181m]
    •    Sight distance East to outbound vehicle = 105m, < [SSD = 181m]
Sight distance therefore does not comply with the general SSD nominated on the RS-056.
To check compliance 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:
             o 0.36 (cars braking on flat);
             o 0.34 (cars braking on 2% downhill grade, outbound);
             o 0.29 (truck braking on flat)
             o 0.27 (truck braking on 2% downhill grade, outbound);
Safe Intersection Sight Distance for the existing property entrance to Lot 429 is calculated
from the AGRD Appendix A 2.5 for the normal case (day) and a range of check scenarios.

 EDD SISD                Sight    Norm-day      Norm-night      Mean-day        Mean-night
                         distance (base case)   (check)         (check)         (check)
 Car inbound                      134m          113m            144m            133m
                         133m
 Truck inbound                    165m          N.C.            N.C.            N.C.
 Car outbound                     135m          N.C.            N.C.            N.C.
                         105m
 Truck outbound                   171m          N.C.            N.C.            N.C.
N.C. = Non-compliant with base case
Assuming a critical gap acceptance time of 5s for both left and right turns from the driveway,
the minimum gap sight distance (MGSD) at 80km/hr is 111m.
Sight distance to the West is therefore compliant for inbound cars only; not trucks. Sight
distance to the East for all outbound traffic remains less than acceptable values.

4.1.2.2.2 Existing driveway formation in the road reserve
The existing driveway to Lot 429 comprises a formed and gravelled crossover, at-grade with
the verge.
The formation at property boundary entrance is 5.8m wide and widens to approximately a 16m
length of the road shoulder. The widening is a result of appropriately formed radii of approx.
5m to both sides of the crossover.
Drainage is provided by a pipe culvert setback approx. 3.5m from the edge of sealed shoulder
which carries table-drain runoff under the crossover. There is no fall away from the road
shoulder to create a low point – the driveway and crossover gradient is uniform at approx. 8%
and falls toward the road shoulder.
The standard of pavement is similar to a Class ‘U3’ unsealed road per Table 2.1 of the
Austroads Guide to Pavement Technology Part 6: Unsealed Pavements:

    •    Natural gravels, pit materials or quarry wastes;
    •    40 mm max. size wearing course, min. 100 mm thick;
    •    55 mm max. size subbase, min. 150 mm thick.




                                                                                Long View
                                                                               Consulting Engineers