Att 2 - Traffic Plan

34 Elm St, Cooroy


2.7      Extended Design Domain – Crash Data Analysis
An EDD assessment is only appropriate when crash data indicates that there are no sight distance
related crashes. To determine whether there have been any sight distance related crashes in this
location, all reported crashes from 1 January 2001 to 31 December 2017 was downloaded from
Queensland Government Data on 3 September 2018.

From the information obtained, there were 2 crashes at the Elm St / Opal St intersection. The
details of these crashes are listed below in Table 3.

Table 3 – Reported Crashes near the Elm St / Opal St intersection

  Crash Ref         Crash      Crash Severity     Crash Date     Crash time /      Crash         Crash Group
     No.            Street                                         weather       Description     Description

                                                                                 Veh'S Same
                  Cooroy
                                                  Friday April    3pm – Dry       Direction:
   230619       Connection     Hospitalisation                                                   Parallel lanes
                                                     2011          Daylight      Right Turn
                    Rd                                                                              turning
                                                                                   S/Swipe

                  Cooroy                           Monday                       Veh'S Adjacent
                              Property Damage                     2pm – Dry                       Intersection
      88129     Connection                        November                        Approach:
                                    only                           Daylight                      from adjacent
                    Rd                              2004                          Thru-Right       approaches

(Data source Courtesy of Queensland Government)

The two crashes identified in the crash data analysis near the Elm St / Opal St intersection have
occurred where a vehicle has attempted a right turn from Elm St to Opal St. These crashes are
not related to restricted sight distances for south bound vehicles on Elm St turning left onto Opal
St. As such, the reported crashes are not relevant to the EDD assessment of vehicles turning left
from Elm St and onto Opal St. This demonstrates that there is not a history of crashes relating to
sight distance for vehicles travelling south on Elm St turning left onto Opal St and the EDD criteria
can be used for this manoeuvre.

2.8      Extended Design Domain - Minimum Sight Distance Calculations
There are three EDD cases that apply to this intersection. These cases are:

      1. Base case (car) (norm-day) (normal conditions)
      2. Check Case (car) (mean-day); and
      3. Base case (truck-day).


The other check cases do not apply due to the intersection being well lit from the four street lights
at the intersection of Elm St and Opal St.

The following values for observation times and longitudinal deceleration have been determined
from Appendix A.2.4 and A.2.5 from Part 4A of Austroads Guide to Road Design and are included
in Table 4 below.


360 Civil Consulting - Traffic Assessment                                                  Page 10 of 22