AHB Walk/Cycle Way Options 

We believe their are two preferred options for the walk/cycleway, each requires a small add-on to the existing clip-on deck in order to provide a walkway on the outer edge of the Eastern deck and a cycleway on the outer edge of the Western deck.

The two options are:

1) A 590mm add-on.  See page 3 of these drawings by Beca.

 2) A 340 mm add-on, as shown here.  

Both options allow for very good connections, particularly on the North Shore side.

We are mindful of the work completed last year by Beca's which was based on the options at either end of the spectrum of 'No widening' and 'Maximum widening'.  Both options were ultimately rejected due to the first being too narrow and the second too expensive (Beca's estimate in June 07: $30 to 40 million).

We believe that Maunsells were engaged to find an optimised solution for the walk/cycleway - likely to somewhere between the two extremes of 'No widening' and 'Maximum widening', so we have real concern that Maunsells has repeated the rejected options as their preferred.

We understand that that the IE has subsequently requested that Maunsell includes the “600mm add-on” as shown in drawing 603 (on page 3 attached) as a preferred option.  We strongly support the IE’s initiative in this request as we believe that this ‘middle option’ is superior for the following reasons:

1. Lower costs: Due to less materials and lower weight (and consequently less strengthening), such an option will be significantly cheaper than the 'maximum add-on' .  It also appears that this option would only require 4 due trough splices to be strengthened (due to changed wheel track alignment), whereas the 'no add-on' and 'maximum add-on' will require 6 trough splices to be strengthened.
   
2. Better Access:  Any widening options of more than 600 mm are likely to require the use of elevators at the northern end because it is not likely the necessary airspace can be obtained from the private residences on Northcote Point.  Elevators are not only very expensive to install, but they also cause delays for commuters, have extra maintenance costs and reduce the connectivity options for the walk/cycle way.  An add-on of 590mm can be accommodated within the available northern approach viaduct because it is 1.06 m wider than the clip-ons narrowest width of 9.757m.(see diagrams A and C from Drawing SK41 of Beca's report: AHB Cycleway - Feasibility Study Stage 1, July 06)
   
3. Adequate lane widths:  With revised hand rails (to meet the new standards) a walk/cycleway width could be 2.6m, whilst traffic lane widths could be 3.4m for lane 1, (which is the de facto bus lane and the would accommodate the wider buses planned by Ritchie's) and 3.2m for Lane 2, with shoulder widths of 250mm.

Given their ultimate rejection last year, we have requested the IE to that Maunsell removes both the 'No add-on' and 'Maximum add-on' options from their preferred options list.

We recommend that the option of the 340mm add-on is included in the preferred options, as we believe that the 340mm add-on could potentially be even  more advantageous than the “600 add-on” given that it provides adequate lane widths, does not require elevators on the Northcote Point and is likely to be less expensive due to the reduced materials and stress loadings of such a 340 mm add-on.