The Levels Bike Route
The Levels Bike Route is the best safe and quiet bike route from the city to Mawson Lakes. There are multiple variations on this route and the one here was a common part of my commuting in from Elizabeth in pre-tunnel days. It adds about 2km to the distance it takes to get to North Terrace via Main North Road, but is far quieter and safer. The new tunnel (2020) makes it better again!
Once you arrive at the ABC building in Collinswood there are multiple options for getting in to the city. And, of course, where you join the route at Mawson Lakes will depend on your starting point. I was usually coming down from Elizabeth and would hook into the Dry Creek Trail at the railway station as I came of the Parafield airport bike path.
(Click to open this photo in a new window. In many browsers you will be able to click on the photo which opens and enlarge it to full size.)
This is the route you would take from Mawson Lakes on mornings when Dry Creek is flowing strongly, because the tunnel is subject to flooding. The map does not show the tunnel route.