The SH1 Avalon Drive Bypass will provide a new free flowing bypass road that will bypass the congested section of Avalon Drive from Rotokauri Road to Norton Road.
The bypass road is approximately two kilometres long and has roundabout intersections at each end. The project commences north of the existing intersection of Rotokauri Road with SH1, diverts to the east away from the existing highway by a roundabout intersection with the bypass running parallel to the railway along vacant ex-railway land. The bypass passes over Forest Lake Road on a new overbridge that was built alongside the existing railway overbridge. The bypass then reconnects with the existing SH1 alignment at a new five-leg roundabout connecting with Norton Road, Lincoln Street and Rifle Range Road. Norton Road has been lowered to pass under a new railway bridge, which replaces the existing railway level crossing.
The Avalon Drive Bypass:
The Avalon Drive Bypass project consisted of:
Transit NZ (formerly) and the NZ Transport Agency (NZTA) made a significant effort to protect the natural, social and physical environment of the area around the SH1 Avalon Drive Bypass project.
The project directly improves the amenity value of the existing length of Avalon Drive from Rotokauri Road to Norton Road by moving a significant amount of traffic onto the new bypass. This will enable the development of this section of local road into a more pedestrian and cyclist friendly environment.
Noise effects from the bypass onto residential areas were mitigated by the construction of patterned noise walls and especially selected road-surfacing material.
Planting of the roundabouts and margins of the bypass road have enhanced the visual aspect of the new bypass and improve the appearance of the redundant railway land. Removal of exotic and invasive species within the Waitawhiriwhiri Gully whas also improved the natural environment.
The underpasses at the roundabouts allow the safe and unrestricted passage of pedestrians and cyclists though the intersections, and encourage the use of these modes of transport. The lowering of the Norton Road intersection together with the construction of the new pedestrian and cycle paths also improve access to the gully area.
Most of the construction during the first 12 months of this project were undertaken away from the road along a strip of land between the railway line and the rear of the existing commercial and industrial premises. Hence, impacts for road users during the first phase of construction were confined to periods when the bypass was being connected to the existing roads. Siltation control measures wiere installed prior to works within the Waitawhiriwhiri Gully and operations were sequenced to prevent affects on the stream and environment. All construction vehicle re-fuelling were undertaken well away from the gully area.
During the second (and final) phase of the project, the Norton Road intersection was closed for approximately 6 months during the construction of the new railway bridge and Norton Road roundabout. Traffic access to Lincoln and Rifle Range Roads were also affected at times by the closure. Motorists were affected during this time while traffic was diverted away from the Norton Road intersection.
During construction there were some additional noise from bridge piling and earthmoving equipment. However this conformed to the consent limits and agreed working hours. Noice walls were constructed to reduce traffic noise that may have affected the residential areas in Lugton Street and Tui Ave.
For the length of the bypass road north of Forest Lake Road all stormwater was collected by a piped drainage system and diverted to a large stormwater detention pond, prior to release to the existing drainage system. This pond was also used during construction as a sediment detention pond to prevent the release of any sediment contaminated runoff.