Ridesharing has finally penetrated the consciousness of mainstream America. Pink mustaches and silver U’s have crept into cities of varying sizes, and the resulting political battles have raised enough of a ruckus to make Uber and Lyft household names. (That’s a relief to us poor tech writers, tired of endlessly explaining ridesharing to baffled relatives in far-flung suburbs.)

Some might say ridesharing has successfully disrupted the status quo — insert obligatory eye roll here. Certain aspects of that disruption have been covered far more extensively than others. The impact on taxis, of course. The state laws, shifting creakily to encompass this new industry that seemingly emerged from Silicon Valley overnight. Background checks, and safety precautions, and insurance.

But ridesharing also “disrupts” a few things that we’ve heard far less about. These companies haven’t said much about their effects — positive or detrimental — on public transit or the environment. They’ve largely stayed mum on…