What do I do about deer, big trucks, deep snow and floodwater on the road?

Four pages in this library take one of these each. Slow down for the deer you haven’t seen yet is the second after a deer crosses your headlights. Pass the truck, or drop back behind it is the long stretch beside a big truck in the next lane. Dig out the tailpipe before you run the heater is the wait in a car stuck in snow. Open the window before the water reaches it is a car going into water, and the flood water it tells you not to drive into.

When a deer crosses in front of you, slow down and expect another one to follow it. If a deer is in your path and you cannot stop, brake hard and keep the car straight in your lane: at road speed, a sudden swerve toward a ditch, a tree or oncoming traffic is what hurts people.

If you have just hit a deer, Slow down for the deer you haven’t seen yet gives these steps first. Move the car somewhere safe if you can and put your hazard lights on. If anyone is hurt, or the animal is blocking the road, call the emergency number — 911 in the US, 999 in the UK, your local emergency number elsewhere; otherwise, call the police. Stay away from the deer, alive or dead. Indiana’s wildlife agency warns that an injured deer is unpredictable and dangerous, and that a deer can survive a direct hit and look dead when it is not; the UK’s National Highways says never try to move a deer off the road yourself.

The page says thirteen separate conversations, among drivers in deer country, carry the same warning: one deer crossing is a sign that more are close behind it, so keep your speed down until you are well past the place it crossed. Others add that when one crosses, the rest tend to follow it straight away, without looking, and that the first one is unlikely to turn back, so look to the side it came from, not the side it went to. Indiana’s wildlife agency puts it in one line: “When you see one deer assume there are more.” Slowing down is the protection; stopping dead in the road, the page says, is a judgement. The UK advice is to brake sharply and stop only if there is no danger of being hit by the traffic behind you, with your hazard lights on. On a quiet road with time to spare, stopping to wait is one choice, and New Jersey’s regulator says to wait for a deer that stands in the road and will not move; on a busy road, slowing and creeping past the spot keeps you out of the way of the car behind.

Many people say it directly: do not swerve to avoid a deer. Brake, hold the wheel straight, stay on the tarmac, and if you cannot stop in time, hit the animal rather than the tree, the ditch, the guardrail or the car coming the other way. Indiana’s wildlife agency puts it flatly: braking and hitting the deer is safer than swerving off the road or into oncoming traffic. New Jersey’s regulator says hold the wheel firmly, brake and come to a stop. The UK’s advice is to try not to suddenly swerve, because hitting oncoming traffic or another obstacle could be worse. The page calls this a judgement with a condition, not a ban on steering: the danger is a sudden jerk of the wheel at road speed, and at low speed, with open space and nothing to hit, one person points out, easing around an animal is a different act.

The same conversations correct the rule for the largest animals: a moose or an elk is tall and heavy enough to come through the windscreen and crush the people inside, one person says, and one person there says that for them, avoiding the impact matters more. The two authorities the page quotes agree with that only in part, and it gives both. Maine’s transport department: apply the brakes and steer straight, let up on the brakes just before impact so the front of the car rises slightly, aim for the tail end of the animal, and duck down to protect yourself from the windscreen. New Brunswick’s: brake firmly and try not to swerve, and if a moose is directly in your path and you cannot stop, consider swerving in a safe direction. Both put braking first. Maine’s advice has no swerve in it at all; New Brunswick’s keeps one only for a large animal directly in your path, only when stopping is impossible, and only in a safe direction. What decides it, the page says, is the road in front of you: a swerve is only a real option into open road, with no oncoming car, no tree and no ditch.

Spend as little time beside a big truck as you can: pass it steadily or drop back behind it, and after you pass, move back in only when you can see the whole front of the truck in your mirror. Pass the truck, or drop back behind it says many people give the same rule and the same test: never linger alongside a truck, because you are in its blind spot, and if you cannot see the driver’s mirrors, the driver cannot see you. So pass decisively, some people say, rather than creeping past its trailer, and if you cannot pass cleanly, drop back until you can see its mirrors again. A truck cannot stop the way your car can, and some people warn against pulling in close in front of one. At 55 miles an hour, New York’s manual says, a car needs about 193 feet to stop and a tractor-trailer needs 256 to 430, figures the page notes vary with load, road and weather. The manual’s rule for passing is to make sure you can see the whole front of the truck before you return to its lane; one person says the same thing as “both headlights”.

In snow, the page says, following a truck at a real distance can help; close, it is a gamble. Others say that in a white-out, a truck’s many lights make it easier to see, and its braking gives you something to follow. Others in the same conversations answer that 80,000 pounds losing grip is very hard to correct, that a truck can spin out or stop suddenly, and that its wheels throw up spray and cut ruts a small car handles badly. One warning there says never within 20 feet in bad weather, and do not assume the truck’s speed is safe for your car — and 20 feet, the page says, is a floor, not a safe gap. The UK Highway Code asks for at least two seconds behind any vehicle on a fast road, at least double that in the wet, and up to ten times that on ice. The decider the snow argument itself gives is distance: whatever you follow, the distance is what keeps you safe, not the vehicle in front.

Before you run the engine for heat, clear the snow from around the tailpipe all the way to the ground; then run it about ten minutes in each hour with a window open slightly, check the pipe each time, and stay awake. Dig out the tailpipe before you run the heater gives these steps. If you are stuck in snow right now: stay with the car, especially in a storm, on ice, or when you cannot see far. Before you run the engine for heat, get out and clear the snow from around the tailpipe — not only the opening, but a space about a foot wide, all the way down to the ground. In a US study of a snow-blocked car, carbon monoxide inside reached dangerous levels within minutes even with the windows open, and stopped only when the snow was cleared that far. Then run the engine about ten minutes in each hour, with one window open slightly, and check the pipe again every time, because falling and drifting snow will block it again. Stay beside the car while you do it: the Weather Service warns that away from it, in wind-driven snow, you can become disoriented quickly. Stay awake. Carbon monoxide has no colour and no smell, and the CDC warns that someone asleep can die of it before they feel anything; a headache, dizziness, weakness, sickness or confusion in a running car means engine off and fresh air. If you are in danger, call the emergency number — 911 in the US, 999 in the UK, your local emergency number elsewhere.

In that study, published in 2004, with the front windows open an inch, and then six inches, carbon monoxide still reached dangerous levels within five minutes, and seven and a half; with the tailpipe swept clear but the snow still banked around it, it was little better. So the window open a little is for fresh air, as the CDC and the Weather Service both advise, and it is not protection; one person on the page says the same of the recirculate button, which does not seal the car, and the page found no test of that. The ten-minutes-an-hour rule and the foot-wide clearing, the page says, are guidance, not a guarantee: a damaged or leaking exhaust can put carbon monoxide in the car even with a clear pipe, and the CDC recommends having the exhaust system checked by a mechanic every year. Staying with the car is the rule in a storm and on open roads; one person describes walking to shelter in a town, in clear weather, on a route they knew, and the page calls that a judgement for those conditions only.

A sinking car floats for about a minute, and that minute is your way out: seatbelt off, window open, children out, then you. Do not wait for the car to fill, and do not spend the minute on the phone or on the door. Open the window before the water reaches it gives these steps. If your car is going into water, you have about a minute while it floats, sometimes much less. Do not phone first and do not try the door. Your seatbelt off, and unlock the doors. Open a side window now, while the power still works; not the windscreen. If it will not open, break a side window at a corner with an escape tool, moving to the back seat to try a rear side window if the front will not go. Children out first, starting with the oldest: undo each one’s belt and push them out through the window ahead of you. Then you: out through the window, and swim for the nearest shore. Once you are out, call the emergency number — 911 in the US, 999 in the UK, your local emergency number elsewhere. Only if every window is shut and cannot be broken, the last resort from one US motoring association: get your head into the highest air, and when the car has filled and the pressure has evened out, take a breath and push the door open.

When a car goes into water, the water outside presses on the doors before the inside has filled, and a door cannot be pushed open against it; in the first moments, before the water is up against the glass, the window still works. After that, one person on the page explains, the battery fails under water, and the water pressing on the glass jams it in its tracks. The car may float for as little as fifteen seconds or as long as about a minute, and the research is blunt that rescue in time is unlikely, so the call can wait until you are out.

The old plan — wait until the water inside is as high as the water outside, and then the door will open — is not wrong as physics, the page says, but as a plan it is the one the research calls a mistake. One person there says why: waiting brings on panic, uses up the air you have, and leaves you escaping from a car that has sunk, with further to come up. The waiting plan keeps one honest place, and only one: if no window will open and none can be broken, the door is the only way left, and it will not open until the car has filled. That is the last resort, not the plan. The windscreen is laminated and will not break into a hole you can climb through, so leave it alone. Side windows in many cars are tempered glass, which shatters into small blunt pieces when struck hard at a corner, where it is weakest; one person notes you may still get small cuts. A growing number of cars have laminated side windows too, which a window punch will not break. The research and a US motoring association disagree on how many; a small label in the bottom corner of each side window says tempered or laminated. If yours are laminated, the window that opens in the first minute is your exit, and your escape tool is for the seatbelt.

The best escape, the page says, is the one you never need. Moving water is stronger than it looks: the US National Weather Service says about 12 inches of rushing water can carry away most cars, and England’s Environment Agency says 30 centimetres of flowing water is enough to move one. Do not drive into flood water, however familiar the road.

Who these pages are not for. The deer page is not driver training, and the right move in the moment depends on your speed, the road and the traffic around you. It does not carry the question of fawns hidden in tall grass at mowing time. If what is in the road is a person — a child, a cyclist, someone on foot — it is not the rule for that; one person says plainly that swerving belongs to that case, where the alternative is someone’s life. And it is written from inside a car: its reasoning rests on a car taking a blow from the front, its conversations say nothing about riders, and a rider-training course is the place for that technique. The truck page is not written for motorcyclists or for professional truck drivers. The tailpipe page is for the wait, not for getting unstuck. If you, or someone with you, is shivering, exhausted, confused, fumbling, slurring or drowsy — the CDC’s signs of hypothermia — or has numb, white or waxy skin, the signs of frostbite, it says get medical help as soon as you can: 911 in the US, 999 in the UK. If the car is buried so deep that you cannot open a door, its conversations do not say what to do; call for help and keep the tailpipe question in mind before you start the engine. The sinking-car page is not training, and cars differ in their windows, locks and seats; it is not for the person on the bank watching a car go in, who should call the emergency number first. And its honest limit, from one person: none of these tools help someone the crash has knocked unconscious, and what to do for a passenger the crash has knocked out is not something its conversations cover.