I've lived most of my life in former streetcar suburbs -- neighborhoods of single-family homes, duplexes, and small apartment buildings that were served by a streetcar line every few blocks. Today, some of those places require cars to get anywhere interesting and back, while some of them have a few well-used bus lines and a ton of local restaurants, groceries, and hardware stores in easy walking distance.
The density tipping point is really low; a few four-plexes on each block, which didn't diminish any of the "neighborhood character" or lead to epic struggles to find parking. (I did still have a car, I just used it a lot less, and was much happier not having to bother.) And it felt a lot nicer than the all-or-nothing neighborhoods that are either single-family homes or large corporate apartment complexes.
Point is, you're right, it doesn't take that much density to make getting around without a car viable for many trips.
Many major and minor cities all across North America were not designed for the car, as much as they may seem so today. They were designed for the streetcar, with commercial blocks strung out along those streetcar corridors.
In older bigger cities these streetcar corridors densified and became commercial districts, while in younger ones they were on the precipice before the car and rigid zoning stopped the transition.
These corridors remain as valuable arteries awaiting a return to their original designs. Simple and affordable upgrades like bus rapid transit, small apartment buildings and bike lanes could once again transition them into being powerful parts of a transportation network that does not rely on car ownership.
> These corridors remain as valuable arteries awaiting a return to their original designs. Simple and affordable upgrades like bus rapid transit, small apartment buildings and bike lanes could once again transition them into being powerful parts of a transportation network that does not rely on car ownership.
Throwing money at public transport doesn't have a good track record in modern North American (US + Canada).
Instead (or in addition) you can try things that are free or even earn money:
- charge for street parking (see https://en.wikipedia.org/wiki/The_High_Cost_of_Free_Parking)
- improve zoning to legalise building (see eg http://urbankchoze.blogspot.com/2014/04/japanese-zoning.html) and legalise density
- remove mandatory minimum parking requirements
- remove other subsidies for car ownership, both explicit and implicit
- consider congestion charges and tolls
Once you enact things like the above, bus rapid transit might even become profitable to run privately. After all streetcars were famously profitable back in the day.
Growing up in Toronto, I always assumed that public transit just provides transportation and nothing more. Their income comes from tickets and from government subsidies.
In areas of the world where profitable private mass transit exists, the transit company also deals in real estate. They own land near stations before construction and either rent it out or sell it. They build and own malls on popular stations. This is a large reason why financially sustainable private transit companies exist. This is also known as value capture.
The upside to private transit companies is that it is not a political debate about how much to subsidize them - they are self-funding.