The 85m ramp

Using the Building Code of Australia's maximum of 1:14 slope for ramps, I'll need 85.4m of ramp to get people onto the bridge.

Which is about 4-5 Cullity Galleries. Yeah. Ridiculous.

I googled the clearance height for trucks, and it's apparently 4.4m, or thereabouts, if you live in Victoria: http://www.vicroads.vic.gov.au/NR/rdonlyres/72300C50-019A-42F5-A952-4559482F7ECF/0/tr1999024.pdf

Which still requires a 61.6m ramp.