fbpx

Theory Test Topics Explained: Safety Margins

Safety margins featured image

Greetings, PassMeFast readers! If you’re dying to pass your theory test, we’ve got some good news for you. We’ve only got three more instalments left to cover in our Theory Test Topics Explained series! This time, we’re focusing our attention on the twelfth topic from the DVSA’s multiple-choice question bank: safety margins.

We’ll explain what this topic involves and why it’s so vital to understand, offer example questions and give you some additional revision resources!


Table of contents: 


Theory Test Topic: Safety margins

What are safety margins

The twelfth topic from the multiple-choice section of the theory test is safety margins. This topic is all about how certain road and weather conditions can affect stopping distances and your ability to handle your vehicle—looking closely at what actions you need to take to make sure you maintain a safe distance (or safety margin) between you and the vehicle in front of you.

You’ll certainly recognise some of the information we cover further below from other Theory Test Topics Explained instalments, but don’t let that lull you into a sense of false security. Every bit of information that we cover is important in helping you build up a solid foundation of theoretical knowledge. So, get your notepad and pen out and carefully make your way through each section. We’ll be testing you at the end!

✓ Safety margins

A safety margin, otherwise known as a following distance, is the space that you need to leave between your vehicle and the vehicle in front of you. This space will help minimise the chances of you colliding with the other vehicle if it happens to slow down suddenly or come to a stop. If you drive too closely to other vehicles, you will not be able to stop in time, which is why tailgating is such a dangerous habit to get into.

✓ Stopping distances

In addition to following distances, you’ve also got to think about stopping distances. This is the time, or distance, it takes for you to come to a complete stop in the event of a potential hazard. It is made up of two components: thinking distance and braking distance.

  • Thinking distance is the time it takes for you to react to a potential hazard. In other words, this is your reaction time.
  • Braking distance is the distance that you travel from when you press down on the brakes to when your car comes to a complete stop.

As you’d probably expect, your stopping distance will vary depending on the speed that you’re travelling at. The faster you’re driving, the slower your reaction times will be and the longer it will take for your brakes to help you come to a stop.

To give you a better understanding of this, we’ve created a diagram, using information from the Highway Code, so that you can see just how long stopping distances can be. (You might want to print this out, as you’ll need to memorise the numbers for potential questions that might crop up in your test!)

Example stopping distances

* These distances are based on dry roads and your vehicle having tyres in good condition

Two second rule

When you’re facing normal road and weather conditions, the best way to keep an adequate safety margin between you and the vehicle in front is to leave a two second gap. But how exactly do you go about measuring this gap?

Pick out a stationary object on the road ahead of you—this could be a lamppost, a road sign or a bus stop. Once the vehicle in front of you passes this stationary object, count down the seconds it takes for you to pass it. If it’s less than two seconds, you’ll know that you’ll need to slow things down.

✓ Weather conditions

The two second rule only applies if you’re dealing with dry road conditions. When facing adverse weather, you’ll need to increase your safety margins to keep yourself, and other road users, safe.

  • If you’re dealing with wet roads, your following distance needs to be doubled—meaning a four second gap.
  • If you’re dealing with icy roads, your following distance needs to be ten times the standard distance—meaning a twenty second gap.

Hot weather

Though you won’t find many people in the UK who will complain about a touch of hot weather, it can cause serious problems for drivers. We’re not just talking about how uncomfortable it can get with leather seats, or how unbearable it is to drive without the A/C running. We’re talking about the actual roads.

If it gets hot enough, the roads can start to soften. This means that your tyres will struggle to get a grip on the road and it will take longer for your brakes to work. If you notice this as you’re driving, make sure that you increase your following distance to account for the longer stopping distance.

Cold weather

In freezing conditions, the roads can become extremely slippery, which will make it very difficult for you to control your vehicle and get a good grip on the road. This is why you need to leave a following distance of at least twenty seconds between your vehicle and the one in front of you.

If you’re heading out in snowy weather, you should first make sure that you have cleared any snow/ice from your vehicle—this includes your windows, mirrors and number plate. You’ll want to stick to a low speed so that you have plenty of time to react to potential hazards and to brake. If you spot a bend up ahead, you should keep your steering to a minimum and slow down progressively.

Pay close attention to your steering and tyres when driving in these types of conditions. If your steering feels quite light, you could be dealing with black ice on the road. In this situation, your best course of action is to let up off the accelerator pedal. If you notice your tyres spinning and struggling to maintain a grip on the snow, switch to a higher gear.

If you’re driving in the snow, you should use the highest gear you can in order to prevent your tyres from spinning and to stay in control of your vehicle.

Heavy rain

When facing wet roads, you should double your following distance and try to avoid driving through deep puddles. If you can’t avoid a puddle, test your brakes afterwards to make sure they’re still working properly. Don’t worry, it’s not a complex process. All you have to do is gently apply your brakes.

If the roads are wet enough, it might lead to your vehicle aquaplaning. In other words, you’ll lose control of your steering and find your vehicle skidding on the road. If this happens, all you have to do is bring your foot up off the accelerator and wait for your steering to go back to normal before braking.

If you’re driving on a dual carriageway or a motorway when it’s raining, you might have to use your dipped headlights due to the spray from other vehicles.

Heavy fog

Unsurprisingly, heavy fog can lead to a reduction in visibility on the roads. This means that you will need to increase your following distance and lower your speed as well. If you can’t see much on the roads, the last thing you want is to be travelling too quickly for you to react.

In terms of your car lights, you should have your dipped headlights on, even if it’s during the day. This will help increase your view of the road ahead, and also alert other road users to your presence. If your view of the road ahead is below 100 metres, you’ll need to turn on your fog lights (but don’t forget to switch them off once your visibility improves).

Heavy wind

Though heavy wind might not seem that intimidating, it can be extremely dangerous, especially when you’re on an open road. If the winds get strong enough, they could blow entire vehicles off course. This means that you’ll need to keep an eye out for the road users who are most vulnerable in these situations, including:

  • Cyclists
  • Motorcyclists
  • Vehicles towing trailers and caravans
  • High-sided vehicles

The best way to avoid potential collisions then is to increase your safety margins and give these road users extra room when you’re driving past them. That way, if a strong gust of wind blows them off course, they won’t hit you.

✓ Roadworks

Whenever roadworks are taking place on the road, you’ll be given plenty of notice through the use of road signs. It’s important that you take note of these signs, as roadworks can lead to serious delays in the flow of traffic, meaning that you’ll need to increase your safety margins.

If you spot the driver ahead of you slowing down due to the introduction of temporary speed limits or traffic lights, increase your following distance (make sure you check your rearview mirror to ensure you’re not being tailgated either). You’ll want to increase this gap even further if you’re travelling behind cyclists or motorcyclists, as they’re prone to skidding on debris found near roadworks.

✓ Contraflow systems

A contraflow system is when traffic in one or more lanes flows in a different direction to the rest of the carriageway. You’ll see these systems on motorways and dual carriageways, in an effort to keep traffic flowing when roadworks are taking place.

When you find yourself in a contraflow system, you will need to lower your speed in good time, pick out the lane you need to be in early on and maintain a safe distance between you and the vehicle in front. If the vehicle ahead of you is slowing down, follow suit and increase your following distance.

✓ Skidding on the road

As we’ve covered, certain road and weather conditions can lead to your tyres struggling to maintain a steady grip on the road. Though these conditions are out of your control, skidding can still be avoided if you follow the correct course of action.

When you’re driving on wet or icy roads, you can reduce the chances of your vehicle skidding by lowering your speed and switching to the best gear for the situation. If you do end up skidding, you can regain control by taking your foot up off the brake pedal, pressing down again, and steering into the direction that you’re skidding in.

Depending on the car you’re driving, you might have additional safety features which will help you maintain control…

Anti-lock Braking Systems (ABS)

Let’s say that you’re driving on icy roads only to spot a hazard up ahead. To avoid a collision, you slam down on your brakes. Due to the conditions on the road, however, your tyres end up locking (losing their grip on the road) and you end up losing control of your steering. Game over, right? Wrong!

Most modern cars come with anti-lock braking systems (ABS), which are designed to stop your car from skidding when you slam down on your brakes. The system keeps your tyres moving when your car slows down, giving you control over your steering and minimising your chances of skidding.

Struggling to remember everything? Don’t worry! We’ve summarised all of the important rules below!

Safety margins rules


Example questions featured image

Multiple-choice questions

The multiple-choice section of your theory test will be made up of 50 questions in total. In order to pass this section, you’ll need to get at least 43 right. To ensure you have a solid foundation of theoretical knowledge, these questions will be taken from all fourteen theory test topics. This is why you should take the time to get to grips with each topic before going in for your test.

If you’d like to see how well you understand safety margins, try out our quiz below!

Let us know how many questions you got right in the comment section below!

Case studies

At the end of the multiple-choice section, you’ll watch a video clip which will show you a driver’s point of view of a scenario on the road, e.g., driving in the countryside, and then answer three multiple-choice questions—highlighting your understanding of the rules of the road and your ability to adapt your knowledge to real life situations.

You can get an idea of what this entails with our five written case studies below. Good luck!

Let us know how many questions you got right in the comment section below!


How to revise safety margins

Two stacks of books, one taller than the other, each with a car on top, floating in clouds

We’ve officially made it to the end of the twelfth theory test topic! We’re now only two topics away from the end! Before you start cheering and booking in your theory test, make sure that you’ve aced the theory test topic safety margins by trying your hand at these tests:

If you’d like even more resources to help you revise for the theory test, give our ultimate theory test revision resources a try. We’d recommend downloading one of the mobile revision apps listed there, as it will help you fit in revision on the go.


Looking for more? Check out our other theory test topic breakdown instalments:

By Bethany Hall

Whether you’re a learner or a pro driver, Bethany is here to help. From defensive driving to the Highway Code, she’ll tell you everything you need know about driving. If she’s not on the road, you’ll probably find Bethany with her head in a book or binge-watching the latest TV show.

Leave a comment

Your email address will not be published. Required fields are marked *