Cars are ticketed or towed when not left in specifically designated areas.
Nobody is "littering" the streets with cars. You just don't agree with the specifics of how the government has allocated the physical space resources under its control so you see it that way.
Consider the emission and noise "litter" cars generate too, I would much rather see a few scooters lying around the place than breathe in diesel fumes everday. Really it's just a temporary issue, a bump in the road to emission-free cities.
I'm not convinced it's a temporary bump, though. Space is at a premium in large cities, especially pedestrian/cycling space. As long as bikeshare companies are allowed to use this space for free and wash themselves of responsibility for the negative externalities, I don't see the nuisance and clutter going away anytime.
Don't get me wrong, I'm definitely on Team Ban Cars. But I think that recent unregulated dockless schemes have demonstrated that access to street/sidewalk space is the limiting factor for these companies, and it's sensible to restrict this access somewhat.
Perhaps cities should take simple first steps to regulate without overburdening bike/scooter shares. Portland has designated spots in the downtown core that are reserved for car shares (not any specific company but you can't park your personal vehicle there). Maybe one every 4-5 blocks. Why not do the same for bike share?
We have a docked system already but Lime scooters litter the sidewalks all over town. Why not remove a few car parking spots and require scooters be parked there? One spot could hold many scooters and keep them off the sidewalks.
This may be easier said than done, but converting roads into shared spaces may be an answer to that.
London for example are phasing in stricter low-emission areas, which should technically mean less cars will be passing through. Eventually, they could re-purpose roads so that the primary function of them is for pedestrians, bikes, bike/scooter storage etc rather than 4+ lanes of car traffic.
That is why I believe it is temporary anyway, it seems natural that cities will head this way.
