35 The Tribunal was not satisfied that the methodology used by Mr Klyne to predict trip generations was representative of traffic volumes in a rural residential subdivision. The Tribunal acknowledges that the default values identified by Mr Klyne are industry accepted values for residential development, however, there was no comparative analysis carried out by Mr Klyne to show the appropriateness of these values being applied to a rural residential setting. The Tribunal also accepts Mr Veal's assertion that trip rates vary significantly depending on the type of residential lot. Mr Veal suggested that the range could vary as much as 1.5 trips to 15 trips per household.
36 According to Mr Klyne, his approach considered the worst case scenario looking at the highest potential for traffic generation in the context of the application. Mr Klyne referenced the default values against the two stages of Ocean Farm Estate by considering a number of factors, such as land use activities, lot size and the provision (or lack thereof) of internal amenities, and developed assumptions on the number of persons per dwelling (based on Australian Bureau of Statistics census data (ABS)) and car ownership. From this he concluded that a "fair and reasonable traffic generation rate for 'Rural Residential' development would be between 6 vehicle trips and 8 vehicle trips per dwelling unit".
37 The fact that the default figures correspond with the Shire's guideline figure of eight vehicle movements per lot per day (as contained in Shire of Gingin Guidelines for Road Works, Drainage and Subdivision Development) does not advance that argument as no background evidence as to the formulation of this figure was lead by the respondent. However, during the hearing Mr Klyne told the Tribunal that this figure was derived from a traffic count of two fully developed residential culs-de-sac within the townsite which, if correct, would correlate with the residential nature of the default figures.
38 The significant increase in the trip generation of Ocean Farm Estate Stage 1 from 1.92 to six to eight trips per household per day is questionable. The Tribunal does not accept Mr Klyne's explanation that there was no guarantee that Stage 1 of Ocean Farm Estate would remain of a rural nature. The Tribunal accepts that there may be some increase in the number of trips generated as the subdivision reaches its full potential and as further rural activities establish in the area; however, based on the lifestyles and travel patterns established over a 26 year period, there was no evidence to support an increase in trip generation of the magnitude suggested by Mr Klyne. Furthermore, the Tribunal considers Mr Klyne's use of the census data in determining trip generation to be at best general in its application, whereas a more detailed analysis of demographic characteristics of the particular locality and a comparative examination of an area reflective of the proposed subdivision, would have assisted the Tribunal in understanding the composition of a rural residential area and the likely trip generation rates that ought to be expected. This methodology would have added weight to any assertions formed based on the census data.
39 The Tribunal prefers the methodology used by Mr Veal in determining trip generation rates as constituting a more rigorous analysis. Mr Veal's analysis involved the collection of local data by providing a measure of two estates in the area, namely, Ocean Farm Estate Stage 1 and Seaview Park. The Tribunal accepts that Mr Veal is well qualified to carry out the type of traffic counts undertaken in the collection of data. It is noted that the traffic generation rate estimated by Mr Veal for Ocean Farm Stage 1 was within a similar range as that indicated by the Shire's traffic counts.
40 Mr Veal's evaluation of Ocean Farm Estate Stage 1 concluded that given the established patterns over the past 26 years, it was unlikely that there would be any substantial increase in the rate of trips generated and estimated the trip generation rate for Ocean Farm Stage 1 to be 2.2 AADT per household, which included an induced traffic factor allowing for the construction of Indian Ocean Drive. In the case of Stage 2, Mr Veal considered the results from both Stage 1 and Seaview Park and based on an evaluation of land use, location, lot sizes, lifestyles and allowing for induced traffic as a result of Indian Ocean Drive, estimated a trip generation rate of 4.0 trips per AADT per household. Mr Klyne under cross-examination conceded that trip generation rates for Seaview Park and Stage 2 would be comparable. The Tribunal is satisfied on the evidence relating to land use and lot sizes, that there is a distinguishable difference between Stage 1 and proposed Stage 2 of Ocean Farm Estate to support a lesser trip rate per household for Stage 1.
41 Accepting the trip generation rates as estimated by Mr Veal and applying the threshold for widening roads as set out in the Shire's guidelines, as the road hierarchy exists (that is without the construction of Indian Ocean Drive), Ocean Farm Road (east of the new north/south link) would require widening to 7.0 metres as well as a requirement to widen Nilgen Road (south of Ocean Farm Road to Sappers Road) to 8.0-9.0 metres. This evidence establishes a nexus between traffic generation arising from the subdivision and the need to upgrade certain roads to accommodate this increase.
42 Both traffic experts agreed that the construction of Indian Ocean Drive will significantly alter traffic patterns as the majority of traffic generated by both stages of Ocean Farm Estate will use Indian Ocean Drive to access its destination. As described above, Mr Klyne's predictions required substantial upgrading of existing roads within Stage 1 to accommodate the redistribution of traffic, whereas Mr Veal asserted, based on his findings, that there was no need to upgrade any roads within the Estate. For the reasons stated above, the Tribunal prefers the modelling undertaken by Mr Veal.
43 At this juncture, the issue before the Tribunal is whether to proceed on the basis of the existing roads or on the basis that Indian Ocean Drive will be constructed before traffic levels exceed thresholds for upgrade.
44 The applicant called Mr Michael Crawford, who is a project manager and consultant currently involved in the "Indian Ocean Drive" project for Main Roads WA, to give evidence on the progress of Indian Ocean Drive. Mr Crawford referred the Tribunal to a media release of the Australian Labour Party (February 2005), which announced a commitment to the construction of Indian Ocean Drive and Stage 2 of the Geraldton Southern Transport Corridor. The media release explained that Indian Ocean Drive will be built in two stages over four years, commencing in 2007. Mr Crawford told the Tribunal that $13 000 000 had been allocated to the construction of the first stage, which involved the portion of Indian Ocean Drive from KW Road connecting into the south-western corner of Ocean Farm Estate. Mr Crawford confirmed that Stage 1 had been scheduled in the Main Road's Program of Works commencing in the financial year of 2007. He further indicated that Stage 1 is planned as a two year project. He conceded that it was possible for funds to be diverted away from the project and that greater certainty of the commencement of project transpired when appropriation of the funds occurs in the annual budget.
45 On this evidence, the Tribunal notes the likelihood of Indian Ocean Drive Stage 1 being constructed within the timeframes of the approval of this subdivision. However, the construction of Indian Ocean Drive is reliant on the actions of a third party and as tenders for the project have not been awarded, there remains a degree of uncertainty as to whether the construction of Indian Ocean Drive Stage 1 will go ahead and if so, when it will occur.
46 To overcome this uncertainty, the Tribunal considers that it would not be unreasonable to impose a condition on the approval of subdivision that links the final stage of the subdivision (refer to Figure 3.1 and Table 3.1 of Mr Veal's report) with a requirement to upgrade certain specified road if tenders for the construction of Indian Ocean Drive Stage 1 have not been awarded. An appropriately worded condition would read as follows: