Evaluating Road Hazards and Choosing A Response: Driving Defensively
Updated Dec. 15, 2020Having conducted a search of the roadway to gather visual information, you must then evaluate what you have seen in order to choose an appropriate response. In accordance with the SEE system, the final step will be to execute that response. Your chosen response must reflect the safest course of action for that driving situation. Sometimes, you will be presented with several hazardous situations and will need to decide which one must take priority.
In most situations, hazards can be avoided by:
There are many hazardous situations in which a driver may choose to take all three of these actions. We will explore these tactics in greater detail further down. Which action you take will depend on your evaluation of the hazard. Evaluate poorly and you may end up increasing risk rather than reducing it.
Predicting danger
Any immediate risks you have spotted must be acted against first. Immediate risks are hazards that will almost certainly lead to a collision or crash if you do not respond evasively. Fortunately, these types of hazards are relatively rare. More often, you will encounter hazards that pose a potential risk. These are situations that may become dangerous; some are more likely to occur than others. To drive defensively, you must become adept at predicting dangerous situations and taking pre-emptive action against them, before they occur. For instance:
- The driver ahead of you has not left enough space between their vehicle and the vehicle they are following. You realize there is a heightened chance of a rear-end collision occurring. An appropriate response would be to increase your own following distance.
- When the green traffic light above the lane you are occupying turns yellow, you know that the vehicles ahead of you will soon be coming to a complete stop. A sensible response would be to begin braking gradually. In doing so, you can avoid rear-ending the vehicle in front and reduce the risk of being rear-ended yourself.
- While driving along a residential street, you notice a group of young children playing with a ball by the side of the road. You can see there is a chance that a child may run into the road, so you respond defensively by reducing your speed.
Anticipating the actions of other road users
While evaluating the risks presented by a hazardous situation, you must endeavor to anticipate the actions of other road users. It is impossible to decide on a safe and appropriate response without first considering the actions that the road users around you may take.
The key to successful anticipation is to expect the unexpected. Most of the time and in all situations in life, the most likely of several potential outcomes is what comes to pass. However, life will sometimes throw you a curveball and you need to be ready when it does. If you always expect drivers at stop signs to yield or pedestrians to occupy the road only at designated crosswalks, you will eventually be caught off guard.
Choosing an appropriate response
With the visual information you have gathered by searching the road, you must use good judgment to decide on the safest course of action. Other factors will also influence your decision, such as:
- Your knowledge of road rules and vehicle control techniques
- Your vehicle control skills
- Your knowledge of how your vehicle handles
Evaluating roadway conditions and deciding on a course of action is a fast, fluid process that occurs many times over, every minute you are behind the wheel. The rate at which you must make these choices depends on how changeable and complex the driving environment is. It is estimated that a driver will make 50 to 60 decisions per mile while driving in city traffic.
Here are some examples of decisions you may make as a driver, based on roadway evaluation:
- Setting your speed at an appropriate level based on the speed limit and road conditions.
- Altering your lane position to avoid a hazard.
- Increasing your following distance to give a distracted driver more room.
- Reducing your speed as you approach a red light or a lane of stopped traffic.
Most of the defensive driving responses you execute will involve adjusting your speed, position or the amount of space around your vehicle.
Adjusting your lane position
An ideal lane position will leave you with a safe bubble of space on both sides of the car. You must monitor and adjust your lane position to ensure you always have the maximum amount of room to maneuver. In “normal” conditions, your vehicle should be positioned in the center of your lane, with an equal amount of space between each side of the car and the adjacent pavement markings. You will need to adjust your lane position when:
- 1
You are on a multilane road, occupying the lane that is closest to the centerline.
Here, you should alter your position to be further right within your lane, to keep a safe distance away from opposing traffic. - 2
New traffic is merging into your lane on the expressway.
If possible, move over to let the new vehicles enter. - 3
You are passing a row of parked cars.
You should shift your position toward the left of your lane, in case a pedestrian steps out from between the parked cars or a car door opens into your lane. - 4
A bicyclist is traveling alongside you.
Move over to allow them more space within the lane.
In addition to maintaining space on both sides of your vehicle, you must also choose the lane position which affords you the best view of the road. To stay safe, you must be able to see clearly and be clearly seen by other road users. If you are obscured, another motorist may choose a path of travel that conflicts with your own. Alter your lane position to maximize visibility when:
- 1
Your current position places you in another vehicle’s blind spot.
Alter your position so that you can be seen. - 2
You are approaching an intersection where buildings, trees or other obstacles prevent you from seeing clearly in all directions.
- 3
Driving toward a blind curve in the road.
Shift left or right to maximize your line of sight around the curve but do not move out of your lane unless you can see that there is no opposing traffic approaching. - 4
A large vehicle on the road ahead of you is blocking your line of sight.
Shift your lane position slightly so that you can see past the vehicle.
You should also adjust your lane position if doing so would help another driver who has made a mistake or is in a tricky situation. Of course, you should only do this if it is possible to achieve without worsening the danger of the situation. For instance:
- 1
If a vehicle is parked on the shoulder of the road.
Shift further away within your lane as you pass them. - 2
If a vehicle attempts to pass you dangerously.
Move over to allow them back into your lane, if they have begun to execute the pass prior to a hill, curve or with an insufficient gap in traffic. - 3
If a dangerous situation forces another vehicle out of their own lane and into your lane.
Move over as much as safely possible to accommodate them.
Adjusting your speed
Most hazardous situations can be made safer by adjusting your speed. More often than not, this will involve a speed reduction. Though, there are some instances when an increase in speed may be warranted. Here are some common roadway situations which would demand a speed adjustment:
- Traffic is becoming heavier as you advance along a road
- The road surface has changed and offers less traction
- You are about to enter a school zone
- It is dusk and visibility is becoming poor
- You encounter a road sign indicating that the speed limit has changed
Ideally, you should choose a speed that is neither significantly faster nor slower than other traffic using the road. If you are traveling at too high a speed, you will be forced to endanger yourself by continually passing the vehicles ahead of you. Driving too slowly also poses a risk, as other vehicles would be forced to pass you. Remember that passing should always be kept to a minimum, as it is an inherently risky activity.
Keeping up with the flow of traffic may require regular adjustments to your speed. Cover braking is a great tactic that will allow you to slow, stop or speed up with ease, depending on how a situation develops. Cover braking involves releasing the accelerator and hovering your foot over the brake pedal, without applying any pressure to it. You should utilize this technique when driving in stop-and-go traffic or whenever the situation on the roadway ahead indicates that you may need to brake.
Increasing your following distance
If your evaluation shows that conditions on the road are risky or becoming less favorable, it is usually wise to increase the distance between your car and the vehicle ahead of you. Increasing your following distance creates a larger cushion of safe space around your vehicle, which will afford you more time to brake or make an evasive maneuver in an emergency. You should increase your following distance when:
- You are being tailgated by another vehicle
- You are driving a vehicle towing a trailer or transporting heavy cargo
- The surface of the road is slippery
- Visibility is poor
- You are following a large vehicle that is obscuring your view
- Approaching a curve in the road or a hill
- Following a motorcyclist
- Approaching a railroad crossing while following a bus or a vehicle displaying hazardous material warning placards
- The driver immediately behind you is attempting to pass you
- There are drivers nearby who appear to be distracted, confused, angry or intoxicated
- You are merging onto an expressway from an acceleration lane
In each of these situations, setting a greater-than-usual following distance will decrease the risk of being involved in a collision, while limiting the severity of a collision if one were to occur. When increasing your following distance, remember to be mindful of the vehicles traveling behind you in your lane. Always tap your brakes to activate your brake lights and reduce your speed gradually. Sudden reductions in speed increase the chances of being rear-ended by another vehicle.
Setting an escape route
While careful evaluation of the roadway should allow you to avoid conflict with other road users, it is important to establish a potential escape route that you can maneuver into if something unexpected happens. Most of the time, you will be able to navigate around hazards by altering your lane position. Your escape route should only be used if the current path of travel you are following becomes completely blocked. Ideally, you should scan the roadway 12 to 15 seconds ahead of your car to identify a potential escape route around your target area.
In setting an escape route, look for a 4 to 5-second gap in traffic in the lane running adjacent to your own. While adjusting your speed and lane position, try to leave enough space around your vehicle that you could safely enter your escape route by switching lanes. Remember that you must check your mirrors and blind spots before performing an evasive maneuver. An escape route is no good if takes you away from one point of conflict, only to put you in another!
Communicating with other road users
You will frequently find that the most appropriate response to a potentially hazardous situation includes communicating with other drivers or road users. The other vehicles with which you share the roadway often pose the biggest threat to your safety. This risk can be lessened considerably, by making sure you have been seen by nearby drivers. Flashing your headlights will often do the trick under such circumstances. One example of this is when you are approaching a blind curve in the road and need to make yourself known to opposing traffic.
Your horn can also be used to warn other motorists of your presence, though it should only be used in an extreme situation when the chances of a collision occurring are great. However, we must note that in some states, it is a legal requirement for motorists to sound their horn when approaching a curve on mountain roads. Check your driving manual to find out if this applies in your area.
Your brake lights can also serve as a useful communication tool when dangerous situations occur. If you are approaching a hazard such as debris in the roadway or the site of a collision, you may warn drivers to your rear of the upcoming threat by flashing your brake lights a couple of times.
Dealing with multiple hazards
What if there are several different dangers to deal with at the same time? As it happens, there will rarely be a roadway situation in which you are not managing multiple hazards to some extent. Sometimes, you will see hazards everywhere your gaze lands while scanning the road. Dealing with this demands prioritization of the threats you are facing; figure out which hazards pose the greatest dangers and take steps to avoid them first.
Here are a few examples of how you may deal with simultaneously occurring hazards:
- 1
There are parked cars lining the right-hand side of the street and oncoming traffic in the lane immediately to your left.
Adjusting your lane position to the left or right would mitigate the risk posed by one of these hazards while increasing the risk posed by the other. Therefore, the safest action is to remain centered in your lane. - 2
On a narrow, two-lane road, a pedestrian is approaching on your side of the street, while a large truck approaches on the other.
Moving over to give the pedestrian room would increase the danger posed by the truck. You should therefore slow down to let the truck pass, before moving left within your lane to accommodate the pedestrian. - 3
A child is riding a bike in your lane to the right of your vehicle while opposing traffic is approaching in the lane to your left.
Here, protecting the child should take priority as they are more likely to swerve left into traffic. You should therefore alter your lane position to the left, even though that places you closer to the opposing stream of vehicles.
Give yourself time to SEE
To search the roadway, evaluate hazards and execute responses in an appropriate order, you must give yourself as much time and space as possible. If you are traveling at an unsafe speed or with too little space around your vehicle, you will not have the time to identify and prioritize dangers on the road. The roadway is a dangerous place. Failing to evaluate risk effectively could have devastating consequences.