Bill Peduto wasn't thrilled when I called. The East End councilman attached to the phrase "presumptive next mayor of Pittsburgh" felt like he'd not only been thrown under the bus, but every bus.

Negative blowback from headlines about the possibility of rerouting Downtown buses -- an idea Mr. Peduto has pushed -- left him feeling ambushed. But he was willing to make one thing clear: He doesn't want less bus access to Downtown's core. He wants more.

If the Port Authority's consultant can't come up with a plan that's better than the status quo by next year, Pittsburgh can stick with what it has, but "you would never design the system to be what we have right now," Mr. Peduto said.

There will be "a full community process" before the first route changes, he promised.

Public skepticism here isn't surprising. Not many American cities are more dependent on public transit than Pittsburgh. Almost a third of Pittsburgh households don't own a car. Big American cities with a higher percentage of homes lacking car keys can be counted on one hand: New York, Washington, Philadelphia, Baltimore and Boston. The five other cities more dependent on public transit, all in the east, are smaller than Pittsburgh.

So even if rerouting Downtown buses didn't affect tens of thousands of suburban commuters -- the Pittsburgh Downtown Partnership says more than half the Golden Triangle's workers use public transit -- it would be a big deal in city neighborhoods.

The fundamental problem for the Port Authority to get around, quite literally, is our freakishly small, triangular Downtown. The schizophrenic street grid may have made sense to the military surveyor who sketched it out in 1784, but it wasn't designed to accommodate thousands of cars, much less the armadas of buses that trundle in and out.

Mr. Peduto, however, sees our diminutive Downtown as a reason a circulator bus should work. Right now, buses coming from the North Side don't make it past Liberty Avenue, and most East Busway rides get no farther west than the corner of Smithfield Street and Sixth Avenue.

What if there were free transfers to a bus that looped the Golden Triangle? What if such a circulator allowed all buses to make only right-hand turns, eliminating those slow, lumbering left-hand turns that stall Downtown traffic in four directions? What if more bus stops were where sidewalks are wide enough to accommodate shelters, rather than in places that have passersby stepping into a bus lane to get by? What if Smithfield Street had a dedicated bike lane?

Downtown's weekday absorption and expulsion of the hordes using all forms of transportation at the same time "makes it challenging, but it doesn't make it impossible," Mr. Peduto said. "Any other city would have a trolley system that runs in a loop."

It may still be quicker for many to walk rather than transfer to a second bus, though maybe that's good, too. That would leave more room on the circulator for those with real trouble getting around.

Mr. Peduto and Allegheny County Executive Rich Fitzgerald promise more accessibility, not less, but the main directive here should be Hippocratic: First, do no harm. Tinkering at the edges is likely to have minimal effect on Downtown congestion, as the example of the North Shore Connector should show us.

Its opening in March 2012 allowed the Port Authority to stop sending the 14 Ohio Valley and the 18 Manchester into the Golden Triangle -- 222 fewer bus trips, in and out, every weekday. Two new North Side T stations also allowed people driving in from the North Hills to avoid the Downtown scrum and its high parking rates altogether by parking across the Allegheny River and taking the free T ride Downtown.

Anywhere from 700 to 1,000 more cars now park each weekday on the North Side, said Merrill Stabile, the Alco parking executive who also manages the publicly owned, 1,300-space parking garage between the stadiums.

Riders on those two bus routes now have a longer commute as they await their transfers to the T, but even with standing-room-only on that slow creaky ride beneath the river at rush hour, has anyone noticed Downtown traffic running more smoothly since all those cars and buses started pulling over on the North Side?

No, it's still a hassle getting to work Downtown. Maybe there's a reason that rearranging the letters in "Golden Triangle" gets you most of the way to "gridlock." There's no real smooth way around it.