What to do if you slide on ice or hit a flooded street

Why Boston gets both problems

This metro has a long, genuinely cold winter and a coastal position that produces storm surge and tidal flooding. The winter brings heavy, repeated snow: the snowiest season on record was 2014-15 at 110.6 inches, with 64.8 inches in February 2015 alone. That freeze-thaw cycle is also what breaks the pavement, which is why pothole season runs from the first thaw straight through spring. Near the harbor the risk changes shape entirely and becomes water, moving fast, in places that sit low against the tide.

Where ice hits first

Ice does not arrive evenly. Bridges, ramps and overpasses lose heat from above and below, so the elevated segments of I-93, the Zakim Bridge, the Tobin Bridge and the ramps around the O'Neill Tunnel portals glaze over while the ground-level road a block away still looks clear. Untreated side streets in the neighborhoods freeze next and stay frozen longest where they get little winter sun. Out on Route 128 and the Mass Pike, open ground west of the metro adds blowing and drifting snow on top of the ice, which is a different hazard again.

Waterfront and low streets

Boston's flood risk on the road is often tidal. A king tide or a coastal storm pushes water up over low streets in the Seaport, East Boston, along Morrissey Boulevard in Dorchester and on the North End waterfront, and it fills those streets while the approach a block inland looks completely normal. Water on a low street is deeper than it appears from a driver's seat, and a stalled car in rising water is a genuinely dangerous place to sit. If the water is still rising, get yourself clear first and tell us that when you call.

Never restart a car that stalled in standing water

If your engine died while you were driving through water, do not turn the key again. An engine draws air in through the intake, and if the intake is sitting below the waterline, cranking the starter pulls water into a cylinder instead of air. Water does not compress the way an air-fuel mixture does, so when the piston comes up to compress it, something has to give, usually a bent connecting rod or a cracked engine block. That single extra crank is often the difference between a car that needs a tow and a car that needs a new engine.

Salvage assessment or a normal tow? What decides it

How high the water got is what matters, not how deep it looked from the driver's seat. If water reached the door sills, the floorboards or higher, treat this as a flood-damage assessment rather than a routine breakdown: get the vehicle to a shop or your insurer's preferred facility for inspection before anyone tries to start it, and let them check the engine, transmission fluid and electrical system before you spend a dollar on repairs. Massachusetts salvage rules attach paperwork to a badly flood- or crash-damaged vehicle, so this decision matters. If the water only came up around the tires and the engine never took a breath of it, this is usually a normal stuck-vehicle recovery and tow. A vehicle that slid into a curb or guardrail on ice should get the same suspension and alignment check before it goes back on the road.

Snow emergencies are part of the winter picture

When the city declares a snow emergency, parking is banned on both sides of every posted "Tow Zone No Parking During Snow Emergency" artery so plows can clear the full width of the street, and a car left on one is ticketed and towed. Separately, street cleaning runs from April 1 to November 30, extended through December 31 in the North End, South End and Beacon Hill, and a street-sweeping tow is run by a private company, not the city lot. Check the posted signs on your block, because when a posted sign differs from the schedule, the posted sign controls.

Why an ice- or flood-affected vehicle goes on a flatbed

A vehicle that slid on ice or sat in standing water, even briefly, may have compromised brakes, a soaked electrical harness, bent suspension or damage in places you cannot see from outside. Ask the assigned operator to quote a flatbed for ice or flood recovery rather than a wheel lift, so nothing drags, nothing spins, and nothing is asked of a drivetrain that might already be damaged.