The proposal seeks to provide 265 basement car parking spaces and the proposed new local link from Gilham Street to Les Shore Drive will allow greater permeability through this part of the area and improve the local road network. However, the Council has recommended that an amended traffic assessment be submitted to assess the impact of the proposal on the performance of the surrounding road network and major junctions, taking into account the proposed road improvements (within the Castle Hill North proposal), additional growth that results from the Castle Hill North proposal and the Pennant Street Target area to the south and the potential impact of the proposed road along the western boundary of the site. As such, the planning proposal, with an estimate of 220 dwellings, would increase the yield of the facility by 88 dwellings over the 132 planned by the Council.
As such, this modest generation should result in a negligible impact on each junction in the network. To test this assumption, SIDRA modeling of key intersections identified by the Council was undertaken. The SIDRA model took the baseline traffic survey count for Gilham Street as recorded in the TRAFFIX TIA report, then added the traffic generation of the subject area in addition to the traffic generation of the proposed higher density sites within the area that have likely to regularly use these two main intersections.
These levels of travel were distributed across key intersections in the distribution patterns identified above (the TSA report noted that Site I has secondary access to Old Castle Hill Road to help distribute this traffic, plus a proposed link road to Lee Shore Place provides alternative access to Pennant Place for locations to the west), resulting in the following additional traffic flows at the key intersections shown in Figures 2 and 3. The planning proposal in question will generate an additional 17 morning peak journeys and 13 PM peak journeys in to the generation that the Council envisioned for the city.
NA: Intersection LOS and Main Road Approach LOS values are not applicable for two-way sign control as the average delay is not a good LOS measure due to zero delays associated with large road movements. Largest change in average back of queue or degree of saturation for any lane during the last three iterations: 0.0 % Number of iterations: 5 (maximum specified: 10). Largest change in average back of queue or degree of saturation for any lane during the last three iterations: 0.0 % Number of iterations: 5 (maximum specified: 10).
Vivien Place, Castle Hill
Access & Internal Design Aspects 24
Location and Site
Existing Traffic Conditions
- Road Network
- Key Intersections
- Public and Active Transport
- Existing Site Generation
Figure 3 shows that the site is conveniently located to the major and local road systems serving the region. Figure 4 shows that Gilham Street terminates to the east at Old Castle Hill Road, forming a priority controlled 'T' junction. Figure 5 shows that Gilham Street terminates to the west at Carramarr Road, forming a priority controlled T-intersection.
As with the eastern end of Gilham Street, one through lane is provided on all approaches with curbside parking permitted. Curbed footpaths are provided on the western reserve of Carramarr Road and the southern reserve of Gilham Street. It can be seen from Figure 6 that Pennant Street, Old Castle Hill Road and McMullen Ave form a four-way signalized intersection.
Pedestrian walkways are provided on both sides of all approaches with pedestrian crossing facilities on all four arms. It can be seen from Figure 7 that McMullen Ave ends at Old Northern Road and forms a signal controlled 'T' intersection. Pedestrian paths are provided on both sides of all approaches with pedestrian crossing facilities provided across McMullan Avenue and the eastbound approach from Old Northern Road.
These bus services provide connections to such centers as Parramatta, Pennant Hills, North Sydney and the Sydney CBD. In addition, a new station for a proposed rail link known as the Sydney Metro North West Link will be located approximately 450m south of the subject site, as indicated. The existing traffic generation is related to the existing 11 residential dwellings located on the site in question.
An assessment was undertaken in accordance with the requirements of the RMS guideline for traffic generating developments (2002) to determine the existing generation of the subject site. The average Sydney weekday travel rates provided by TDT 2013/04a were adopted for assessing the existing traffic generation of the subject site. The results of this assessment will be used to derive the expected net change in traffic generation for the subject site following the full development of the concept proposal.
Description of Proposed Development
- Parking Controls
A limited parking provision will lead to the achievement of a lower traffic generation rate for the site in question, reducing the resulting impact on the local network. However, it is worth noting that the subject site has no obvious limitations and the required parking can generally be provided at basement level.
- Trip Generation
- Net Traffic Impact
- Traffic Distribution
- Peak Period Intersection Performances
- Residential Amenity
In order to estimate the expected traffic distribution from the subject development, an interrogation of commuting data provided by the NSW Government Office of Transport Statistics was carried out. 50% travel south towards destinations such as Baulkham Hills, Parramatta and Strathfield via Old Castle Hill Road and Terminus Road;. 33% travel eastwards to the CBD, North Shore, Eastern Suburbs and Inner West via Old Castle Hill Road and Old Northern Road;.
12% travel west towards centers such as Blacktown and Penrith via Old Castle Hill Road and Pennant Street; and. To assess this impact, SIDRA modeling of the critical AM and PM peak periods at the central intersections identified in Section 3.1 has been undertaken. For the purpose of assessing the traffic impacts of this development, traffic count surveys were undertaken of the most critical intersections immediately around the site as identified in section 3.2, being the intersections of Gilham Street / Old Castle Hill Road, Old Castle Hill Road / Pennant Street, McMullen Ave / Old Northern Road and Gilham Street / Carramarr Road.
AVD - The AVD for individual intersections provides a measure of the operational efficiency of the intersection. Additionally, the Old Castle Hill Rd / Pennant St intersection is seen to be south of the site. For the Old Northern Road/McMullen Avenue South East intersection, existing conditions record an 'F' service level during the morning peak with a satisfactory 'C' service level during the afternoon peak.
A review of the detailed SIDRA outputs (included in Appendix C) reveals that the saturated motions in the AM peak are associated with eastbound traffic on Old Northern Road traveling through the intersection and continuing east and southbound motion direction on Old Northern Road turning right onto McMullen Avenue. In this regard, traffic related to the affected location causes minimal impact to the overall operation of the Old Northern Rd/McMullen Ave intersection. In this regard, the effects of the planning proposal on the wider network are considered acceptable, with no need for external improvements to support concept development.
The potential effects of the development on the amenity value of the existing residents are best assessed in view of the traffic intensity on the affected road sections, based on the concept of. It should be recognized that the concept of a road's "environmental capacity" is not an exact science. These variables are described in section 4.3 of the RMS Guide to Traffic Generating Developments.
Access & Internal Design Aspects
- Vehicle Access
- TYPICAL BASEMENT LEVEL
- LOWER GROUND
- TYPICAL GROUND
- TYPICAL MID LEVELS
- TYPICAL UPPER LEVELS
- TYPICAL UPPER LEVEL
One Page Summary
Site: J04 - Old Northern Rd x McMullen Ave_PM - Existing Network: Network_PM - Existing Intersection: Old Northern Road x McMullen Avenue. Level of Service (LOS) method: SIDRA Pedestrian LOS method (based on average deceleration) Pedestrian movement LOS values are based on average deceleration per pedestrian movement. Location: J04 - Old Northern Rd x McMullen Ave_AM - Existing Network: Network_AM - Existing Intersection: Old Northern Road x McMullen Avenue.
Terrain: J02 - Gilham St x Old Castle Hill Rd_PM - Existing Network: Netwerk_PM - Existing Intersection: Gilham St x Old Castle Hill Road. Terrain: J02 - Gilham St x Old Castle Hill Rd_AM - Existing Network: Netwerk_AM - Existing Intersection: Gilham Street x Old Castle Hill Road. Terrain: J01 - Gilham St x Carramarr Rd_PM - Existing Network: Netwerk_PM - Existing Intersection: Gilham Street x Carramarr Road.
Site: J01 - Gilham St x Carramarr Rd_AM - Existing Network: Network_AM - Existing Junction: Gilham Street x Carramarr Road. Site: J04 - Old Northern Rd x McMullen Ave_PM - Existing + DEV Network: Network_PM - Existing + DEV Intersection: Old Northern Road x McMullen Avenue. Site: J04 - Old Northern Rd x McMullen Ave_AM - Existing + DEV Network: Network_AM - Existing + DEV Intersection: Old Northern Road x McMullen Avenue.
Terrain: J02 - Gilham St x Old Castle Hill Rd_PM - Existing +DEV Network: Network_PM - Existing +DEV Junction: Gilham St x Old Castle Hill Road. Terrain: J02 - Gilham St x Old Castle Hill Rd_AM - Existing +DEV Network: Network_AM - Existing +DEV Junction: Gilham St x Old Castle Hill Road. Terrain: J01 - Gilham St x Carramarr Rd_PM - Existing +DEV Network: Netwerk_PM - Existing +DEV Junction: Gilham Street x Carramarr Road.