Mayor Bill de Blasio riding a new Select Bus, one of the city’s rare recent successes in transportation EDWIN J. TORRES/MAYORAL PHOTOGRAPHY OFFICE

Mayor Bill de Blasio never makes it easy for himself. Whether it’s due to any number of self-inflicted PR imbroglios, the failure to build relationships with natural allies, or his all-around preachiness, he enters his second term in a strange place: comfortably re-elected but not particularly beloved.

His quest to reduce New York City’s enormous income inequality is admirable, if frustratingly vague. Last year, he promised a lot of “good-paying” jobs but did little to deliver them. Now casting about for national relevance, he seems to be running out of ideas for solving our inequality crisis.

His lofty rhetoric could meet on-the-ground reality if he ever deigned to care about New York’s distressing bus system. It’s been the great oversight of his tenure and a galling one. Where he could make a profound difference in the lives of the poorest New Yorkers and seniors, he’s chosen to maintain an unacceptable status quo.

Why? It’s never been clear. De Blasio launched out of the gate with universal prekindergarten and forged ahead on a developer-friendly plan to build a lot more affordable housing in the five boroughs, but never gave much thought to transportation. A few years ago, he tossed out the idea for an overpriced streetcar with a dubious funding mechanism — a streetcar that would also pass through flood zones.

Ramping up the ferries, an achievement de Blasio often touts, has been beneficial for a few coastal neighborhoods. He must also remember the system carries about as many people in a year as the subways do in a day.

De Blasio has the moral high ground when battling Governor Andrew Cuomo over funding the MTA — it’s a state-run authority with little input from the city — but loses it elsewhere. He doesn’t need the MTA to speed up our buses and increase their capacity. He runs these streets, after all.

Last summer, various transit advocates launched a campaign to improve bus service. Their cries came on the heels of a few sobering statistics: The bus system in 2015 provided 46 million fewer trips than it did in 2010. The 46 million trip decline was “greater than the annual ridership of the bus system serving San Antonio,” a city report noted. Bus speeds declined more than 2 percent.

Ridership is falling for a variety of reasons. Until recently, the subway was attracting many more riders. Uber, Lyft, and other for-hire apps have attracted former bus riders, adding convenience while also clogging roadways.

Many bus routes are also outdated. Bus lanes are still lacking on most roadways. Buses often don’t show up when they’re supposed to.

Like the subway, the bus system is deteriorating, shedding ridership as service falters. Unlike the subway, its fixes are relatively cheap.

The city can re-evaluate routes for efficiency, something it rarely does, and undertake an effort to redraw the map to suit new commuting patterns. All-door boarding and tap-and-go fare collection could dramatically cut down on the time it takes to drop people off and pick them up. Technology could give buses priority at traffic signals.

Select Bus Service, pioneered under Mayor Michael Bloomberg, has added ridership, a rare success story in an otherwise dismal transportation landscape. Last year, de Blasio touted the proposed addition of 21 new routes.

Transit advocates didn’t exactly dance in the streets. De Blasio’s timeframe? Ten years, far beyond his mayoralty and a staggering amount of time for the implementation of relatively few routes. We should demand far more SBS.

In the meantime, our bus fleet remains the slowest in the nation, an embarrassment for a city that fancies itself a progressive leader. Why is de Blasio tolerating this? Why isn’t he launching an all-out campaign to fix the buses?

It would be so easy to meld de Blasio’s lofty rhetoric with a campaign for his beleaguered bus system. The very people he professes he wants to help — the poor, seniors, people of color — are trapped on failing buses. They are stranded on the outer fringes of a deeply unaffordable city, commuting several hours a day for jobs that can barely pay the bills.

De Blasio wouldn’t have to confront an antagonistic governor or an obstructionist Republican state senate to change this reality. He wouldn’t need Albany.

By subsidizing a ferry program that also circumvented Albany’s tentacles, de Blasio could claim he was doing a transit mitzvah for the common man. Perhaps there was a certain allure to aquatic transit — press conferences near ferry terminals are more scenic than those on asphalt. A boat has a certain je ne sais quoi that a bus lacks.

But boats and streetcars through gentrification zones will only get us so far. If de Blasio wants to solve the tale of two cities and live up to the expectations set so high four years ago, he should look to his own roadways. It’s the least he can do.