In general, if you design your infrastructure for a 60-year old woman with two bags of groceries, you can make cycling attractive to a huge range of the population.
I have referred to Jarrett Walker's website, Human Transit, already. His latest blog entry is just brilliant and is something everyone who works for a suburban railway or tramway system should read.
In a city like Adelaide, that is spread out, an argument against spending on public transport is that it is impossible for it to serve a catchment area wide enough for the transport to be viable. One reason for the success of the o-bahn is said to be the fact that it can serve a large catchment area. Buses can come from various places and meet at Tea Tree Plaza or Paradise before joining the o-bahn track into the city. Trains do not have the same ability.
An obvious way to increase the catchment area is to encourage people to cycle. I have read that a bicycle can increase a person's own catchment area by 10 or 15 times. It certainly sounds plausible to me. You make it easier and more people will use the facility. Hence the quote.
Here is the article. It is well worth a read.