Expensive restaurants, dog parks and gyms have long been seen as symbols of gentrification — a loaded term generally understood to mean new wealth and people that flood into an area, displacing longtime residents or making new amenities unaffordable to them. But what is it about bike lanes, which are city infrastructure that’s free to use, that pack meetings?This is an interesting issue because it blends at least two distinct ways in which our current urban policy setup in the US disproportionately harms poor people. First, financial and regulatory subsidies for car ownership and car-optimized growth make it tough to be carless - and cars are expensive. Car-centric land use policies also produce economically fragile municipalities by reducing the ratio of private to public investment (higher upkeep liability for less tax revenue). Weak and unsustainable public finance situations among local governments reduce the supply of government services, of which the poor disproportionately benefit.
Second, restrictions on building houses (such as zoning, height caps and minimum parking requirements) limit the ability of awesome neighborhoods to add supply in order to keep prices level in the face of increasing demand. These supply restrictions mean that the only viable alternative to stop displacement is to reduce demand by restricting amenities - solutions that are both ineffective and perverse.
Which brings us back to bike lanes. Bike lanes are pretty clearly a benefit for cities, mostly because they mitigate some of the disastrous consequences of the auto-centric urban design model at a modest cost. But because of the perverse incentives created by housing restrictions, the amenity is reasonably opposed by people at risk of being displaced.
Ultimately this comes down to one's view of policy change. If you think reforming the housing supply situation is futile, then opposing amenities like bike lanes can make sense. But this is a somewhat defensive and short-term mode of thinking about individual cases: fight lots of little battles to conserve what you've got.
A more aspirational, long-term approach might conclude that opposing amenities based on their immediate, local displacement effects is a recipe for stagnation and decay. And indeed, amenities can have other useful effects on social and policy norms that over time reduce their displacement impact: if bike lanes really take off and show up everywhere as a road design standard, their effect on nudging demand to this or that neighborhood goes away.