The Times notes the ridiculous extent to which ERs are overused for routine medicine:
In a snapshot of systemic waste, researchers have calculated that more than half of the 354 million doctor visits made each year for acute medical care, like for fevers, stomachaches and coughs, are not with a patient’s primary physician, and that more than a quarter take place in hospital emergency rooms.
In a system full of waste, this is ridiculously low-hanging fruit. Anyone with any experience in ERs knows that a great deal of their work could, and should, be done elsewhere. ER docs don't know patients, don't have their records, don't work in continuity of care before or after the visit. More tests get ordered; less complete care given. Nothing gets prevented. The meter runs much, much faster than anyone not in the system realizes; the average visit costs around $1000-1500. And it isn't as if anyone actually likes waiting an hour or two in an ER to see a doc for a head cold, or because a gazillion others are before you in line with their head colds.
But the ER is, by law, sort of like Robert Frost's home: when you have to go there, they have to take you in. Always open. In some places, if you have Medicaid you can get an ambulance ride there for free, even if grotesquely unnecessary and expensive, rather than pay for a cab.
The obvious alternative is access to a primary care physician, in whose practice you're already enrolled, and whose job it is to be the first to respond to acute needs as part of general care, rather than in isolation from it. Won't happen if every last incentive deters docs from entering primary care or staying in it.