How do you know if you’re driving too close to the car in front of you? In fact, most drivers underestimate how long it will take to stop the car.
The gold standard in defensive driving is the 3-second rule. But, it depends on how fast you’re driving when you hit the brakes. The faster you’re driving the slower you’ll come to a stop.
We’re going to help you answer the biggest question drivers face when they’re dealing with a tailgater — what is a safe following distance?
How To Use The 3-Second Rule
It’s easy to use the 3-second rule.
- Use a point of reference, like a tree, lamppost, or anything by the roadside.
- Start counting when the car in front of you passes it.
- Stop counting when you pass the point of reference.
If it’s 3 seconds or more and you’re driving within the speed limit then you’re at a safe distance. (provided you’re not driving in a hazardous situation, more on that below)
Finally, make sure you’re not counting too fast. The correct pace would be; 1-1,000, 2-1,000, and 3-1,000. Or you can also count “one-thousand-one, one-thousand-two, one-thousand-three.” Whichever is easier to remember to you.
There’s also the 2-second rule in dry weather and even the 4-second rule if the roads are wet. In any case, it depends on how safe you want to be in case of an emergency. We recommend that you use the 3-second rule at a minimum to be safe. (1)
When To Further Increase Your Distance
The 3-second rule is just a rule of thumb. You’ll want to increase your distance even more if you encounter these situations:
Bad Driving Conditions
If it’s snowing or raining then it’s going to be hard to stop on time. The road is going to be slippery and your Anti-lock Braking System (ABS) is going to take longer to stop the car.
The same thing applies if you’re driving at night or you encounter crosswinds. Your reaction might be slower since your visibility is affected and your car’s unstable.
Large Vehicles
If you’re driving large trucks or vehicles it takes a long time to stop the vehicle due to the extra load.
And if you’re following a large vehicle, use the 4-second rule or longer. You want to create enough distance to have a wider viewing angle and prevent blind spots.
Some experts recommend that you stay 200 to 300 feet back. (Approximately 15 to 20 cars length)
Merging
It can be tricky to merge into a highway so leave some room between your vehicles and others. Even when the traffic is slow, most drivers are distracted on the road. This leads us to our next point…
Distractions
Remove all distractions if possible, phones, food, and drinks. If you need to grab an incoming call, it’s best to increase your distance further and reduce your speed.
Other Small Vehicles
Motorcycles and even bicycles can fall over easily so it’s better to keep your distance.
Transportation Vehicles
Public buses, taxis, and food delivery vehicles can make sudden and frequent stops. It pays to be alert when they’re around.
Speeding
The faster you drive, the longer it takes for you to stop. Your reaction time plus braking distance is your total stopping distance.
The older you are, the slower your reaction speed. Generally, it takes 0.2 seconds to 2 seconds before you slam the brakes if the car in front of you stops.
Braking distance is depending on your traveling speed. Doubling your speed will double your braking distance.
So if you drive 10 feet before braking and it takes another 20 feet before the car stops, your Total Stopping Distance is 30 feet.
This is why changing your brake pads regularly is critical for your safety. (2)
Here’s the average total stopping distance adjusted for traveling speed (normal road condition):
| Speed | Reaction Distance | Braking Distance | Total Stopping Distance |
|---|---|---|---|
| 25 mph | 56+ ft | 29 ft | 85 ft |
| 30 mph | 68+ ft | 46 ft | 114 ft |
| 37 mph | 82+ ft | 65 ft | 147 ft |
| 43 mph | 95+ ft | 89 ft | 184 ft |
| 50 mph | 108+ ft | 118 ft | 226 ft |
| 56 mph | 125+ ft | 148 ft | 273 ft |
| 62 mph | 138+ ft | 184 ft | 332 ft |
| 68 mph | 151+ ft | 220 ft | 371 ft |
Here’s the same chart in meters (considering normal road condition):
| Speed | Reaction Distance | Braking Distance | Total Stopping Distance |
|---|---|---|---|
| 40 km/h | 17m | 29 ft | 85 ft |
| 50 km/h | 21m | 46 ft | 114 ft |
| 60 km/h | 25m | 65 ft | 147 ft |
| 70 km/h | 29m | 89 ft | 184 ft |
| 80 km/h | 33m | 118 ft | 226 ft |
| 90 km/h | 38m | 148 ft | 273 ft |
| 100 km/h | 42m | 184 ft | 322 ft |
| 110 km/h | 46m | 220 ft | 371 ft |
Tailgating
First, don’t tailgate others, it’s dangerous.
But if you’re being tailgated it’s important that you keep a distance from the car in front of you. So you can change lanes to let the car through or stop in time if it hits you.
According to insurance companies for Tailgating violations, this is list of states with the most aggressive drivers:
- Idaho
- Georgia
- Nebraska
- Virginia
- Washington
- Ohio
- Utah
- Oregon
- Colorado
- Connecticut
How To Drive Safely With Defensive Driving
Creating a safe distance with the car in front is not the only way to be safer on the road.
Defensive driving or accident prevention driving means:
- Be alert to your environment
- Anticipate potential hazards before it happens
Here’s how:
- Get rid of all potential distractions. (like I mentioned above)
- Focus on what’s happening around you. This includes being aware of traffic and road signs and other drivers.
- Know your stopping distance and use the appropriate following distance. (The weather, visibility, and even your vehicle’s condition affect your total stopping distance)
Frequently Asked Questions About Safe Following Distance
What is a safe following distance for cars in a normal road condition?
It’s best to maintain at least a 243 feet distance from the car in front of you. This is about 16 car’s length.
What is a safe following distance for trucks?
For bigger vehicles like a truck, it’s better to increase your distance to 300 feet or about 20 car’s length. This is assuming a normal road condition and driving speed of around 55 mph. You’ll need to increase your distance if you’re driving faster or if it’s a rainy day.
How do you calculate the safe following distance for speed?
You can refer to the Total Stopping Distance chart above to get an estimate. But here’s the formula.
If you’re traveling 70 mph, you’ll want to find out how many feet you are traveling in an hour.
There’s 5,280 feet in a mile, so 70mph*5280 = 369,600 feet per hour
Then you’ll want to find out how many feet you’re traveling per minute.
369,600/60 minutes = 6,160 feet per minute.
Finally, to calculate how many feet you’re traveling per second at 70mph you’ll divide 6,160 with 60 seconds.
This means you’re traveling at 102.66 feet per second.
However, if you’re following the 3-second rule, that means the safe following distance is about 308 feet.
This is just a rough formula, always follow the recommendations by authorities.
When do I need to use the 5-second rule?
You can use the 5-second rule for hazardous road conditions or when you’re following a large vehicle.
Why you should not tailgate?
If you tailgate, you don’t have time to stop if anything happens. Imagine this, at 70mph your car’s covering 102.66 feet per second.
That’s almost 7 cars in length in a second.
There’s no way to stop your car in time when you’re just right behind another’s car.
And according to a study by the National Highway Traffic Safety Administration (NHTSA) 87% of rear-end car accidents happen because the driver was not paying attention.
What distance is considered tailgating?
If you’re too near to stop and the vehicle in front of you stops suddenly then it’s considered tailgating. In some states, it’s defined in terms of a specific distance or time interval.
It’s even illegal in most states but rarely enforced because it can be hard to prove.
