Allowing the construction of mixed-use medium density buildings reduces the distance of the average trip, which allows more people to choose walking and cycling.
At the end of the day, the more you design a neighborhood to facilitate driving, the more car traffic it will suffer. And the more convenient you make it to any other form of transportation, the less car traffic there will be.
Allowing the construction of mixed-use medium density buildings reduces the distance of the average trip several decades from now, after the new zoning has filtered out into the already-constructed installed base of existing buildings. That doesn't mean we shouldn't do it -- in fact we should do it immediately for precisely this reason -- but you can't expect it to have an instantaneous effect.
Meanwhile people keep proposing things like bus lanes as something we should do in the present day, in places where they can't work until after that construction has already happened. Also, bus lanes are never a good idea because the density required to justify a bus lane (which is very high because it consumes a significant amount of surface land in an area with high land scarcity) is higher than the density required to justify a subway line (which doesn't).
Unless we push for better transportation infrastructure today it won't be there thirty years from now. Nobody is suggesting to put a bus lane in a boring cul-de-sac, either.
For several decades, North American suburbanites have been living comfortably in their quiet bubble of car-dependent neighborhoods, completely disregarding the noise, danger and other externalities that their traffic imposes onto the people who choose sustainable transportation options in more densely-populated urban areas. It's time that we design our urban neighborhoods around the daily needs of the people actually living there rather than the speed and convenience of visitors.
> Unless we push for better transportation infrastructure today it won't be there thirty years from now.
It takes 30 years to completely reshape the housing market because there just aren't enough construction companies, and existing homes don't go on the market, to do it faster than that. It doesn't take 30 years to build a subway line, or if it does then your government is dysfunctional and you should focus on fixing that.
Meanwhile if you try to build the transit infrastructure before there is any demand for it, nobody uses it and you lose public support for even maintaining it because it turns into a money pit with high costs and low usage. And you get punished by the voters because the thing you put in place can't be used while the housing situation is still what it is, whereas the thing they have to use is now worse because the bus lane carrying empty buses nobody can practically use is consuming a travel lane that used to carry more cars.
> Nobody is suggesting to put a bus lane in a boring cul-de-sac, either.
The problem is that nobody is suggesting to put a bus in a boring cul-de-sac, because that would be highly inefficient and not have enough ridership to justify it. But then the people who live there can't take the bus because there isn't one, so they also can't use a bus lane when they get to the main road, and become angry with you when the disused bus lane makes the traffic worse.
> It's time that we design our urban neighborhoods around the daily needs of the people actually living there rather than the speed and convenience of visitors.
It's generally worth considering how those "visitors" will respond to that in terms of where they set up shop and how they vote.
At the end of the day, the more you design a neighborhood to facilitate driving, the more car traffic it will suffer. And the more convenient you make it to any other form of transportation, the less car traffic there will be.