This cache is not on a dual carriage way, nor do you need to walk across one to get to it. Depending on which map you're using, the location may appear to be amongst busy roads, but this is far from reality as you will follow a pedestrian path up and over the road, completely unaware of the traffic in the tunnel below. The highway was recently shifted slightly westwards, so many maps are outdated still, but the satellite view shows the work being undertaken.
Camana Bay is a relatively new development (2008) that aims to link the waterfront of the North Sound with the Seven Mile Beach, promoting walkability, connectivity, sustainability and diversity. It's a great place to relax in the shade in one of the many courtyards, read a book on the waterfront, chill in a hammock on the island or browse the shops and restaurants.
To get to the cache, simply follow the pedestrian link from the main avenue (The Paseo) up the slope that is known as The Rise. During the Easter weekend, this pathway is decorated with chalk drawings for ChalkFest. It is lined with flower beds and offers a great view, although not as far as from the Observation Tower!
Whilst the slope is wheelchair accessible, the final 4-5 metres might be difficult as there is a gravel path in the garden that must be followed. There are nearby benches and a good view from up here!