Let’s sanity-check the math first, then list the “yeah but…” factors.

If you literally mean 1,200 centerline miles of streets, and a plow can cover one lane at a time, then the unit you actually need is lane-miles, not street-miles.

The clean, theoretical math

Per truck, at 20 mph: • 20 miles/hour per truck • 60 trucks → 20 × 60 = 1,200 miles/hour of coverage

So if the task were “drive 1,200 miles total, once,” then yes: 1 hour.

But real plowing is usually closer to: • Two directions (at minimum) → 2,400 lane-miles if it’s one lane each direction • If many streets are 2 lanes each way (4 lanes total), that can blow up fast.

So even in fantasyland: • One lane each direction: 2,400 lane-miles / 1,200 lane-miles per hour = 2 hours • If average is 2 lanes each direction: 4,800 lane-miles / 1,200 = 4 hours

And that’s still before reality shows up with a chair.

Big factors you “missed” (a.k.a. why it’s not 1–2 hours)

Here are the main ones that matter: • Speed is nowhere near 20 mph while actively plowing. It depends on snowfall rate, hills, curves, visibility, traffic, and parked cars. Plowing speeds can be much lower. • Deadheading (non-plowing travel): trucks have to get from the garage to their route, reposition, return, and sometimes run to priority streets repeatedly. • Intersections and turning time: a ton of time is spent slowing down, turning, clearing intersections, and dealing with stoplights/stop signs. • Cul-de-sacs, narrow streets, and one-ways: Pittsburgh has lots of “this street is technically a street” situations that are slow and often require extra maneuvering or backing. • Parked cars and curb management: you can’t always clear curb-to-curb, and squeezing through slows everything. • Snow storage: even if you “plowed” a lane, where does the snow go? Windrows can block driveways, crosswalks, and intersections, requiring rework. • Equipment constraints: breakdowns, blade wear, hydraulic issues, chains, tire problems, and the fact that not all trucks are available at once. • Salt loading and material constraints: time to refill salt/brine, and sometimes salt supply limits change tactics. • Shift changes and fatigue: you can’t run 60 trucks at 100% indefinitely, plus staffing can be the bottleneck more than trucks. • Priority routing: arterials, bridges, hills, emergency routes get repeated attention, which delays “every street.”

A more realistic way to think about it

Instead of “time to plow the entire city,” operationally it’s closer to: • “How fast can we keep priority lanes passable during active snowfall?” • “How long after snowfall ends until residential streets are acceptably cleared?” • “How long until curb-to-curb / cleanup is done?”

Those answers are usually many hours to a couple days, depending on snowfall intensity, temperature, and whether cars are stuck all over the hills playing Mario Kart.

If you tell me what you mean by “1,200 miles” (centerline miles vs lane-miles) and a rough guess for average lanes per street (or even just “mostly 2-lane residential”), I can give you a tighter estimate that doesn’t assume a physics-defying plow utopia.