At least two car legnth for evry mile.

2 seconds. By law the if the vehicle in front of you passes a stationary object, you should not pass it any sooner than 2 seconds later.

You should allow at least one car length for every ten miles per hour. Thus, if you are traveling 60 miles per hour, you should allow at least six car lengths between your vehicle and the one ahead of you. Of course, my experience is that someone always jets their vehicle into my "safety zone," requiring me repeatedly compensate. But, I would rather compensate for those irratating traffic lane weavers rather than travel bumper to bumper at a high rate of speed.

Find a road marker ahead and count one one thousand, two one thousand, and three one thousand. Once you hit the three one thousand, you should be passing the road marker you chose. this is the safe distance from one vehicle to another. Do drivers do this? no.

In Pennsylvania, 4 seconds.

At least 5 feet.

2 seconds would be my guess

2 car lengths. I think.

The legal answer would be far enough behind to come to a safe stop if the vehicle in front of you suddenly stopped. If you are going 60 mph you are traveling at 88 feet per second. Lets say you are following a vehicle that suddenly slams on it's brakes. studys show that an alert driver will take about 1 second to see the brake lights and another second to move their foot from the gas to the brake. This 2 seconds = 196 feet traveled. The vehicle in front of you has been slowing this entire time. Now your vehicle begins to slow at the same rate. If you were 200 feet behind the vehicle in front of you you will come to a stop 4 feet from the rear bumper of it. If they hit someone else or their car had sport tires and big brakes they will stop faster and you will hit them. You will also hit them if you take any longer than 1 second to figure out what is happining. I worked in brake testing.. The simple answer is two seconds.. As the vehicle in front of you passes a stationary object start counting one thousand one, one thousand two. Your vehicle should not pass the fixed point untill after you reach two. I have heard of the 1 car lenght per 10 mph rule as well, but I don't think I could judge 6 car lenghts at 60 mph. I know I can count to two..

4 second law in pa. in some places in pa they have dots painted on the road and you have to stay so many dots behind the car in front of you

Far enough to avoid hitting it if it suddenly stops. Far enough to safely move around it should it stall. (You should NOT have to back up in traffic.)

If you could ask the guy that was behind me a few minutes ago he would probably say ''Just back far enough until the label on the other guys underwear is blurred''.

We have a guide here, one car length feet per 10 mph. Example, 60 MPR would be 6 car lengths. It doesnt quite happen that way, but we have a guideline, hehe.

One car length for every 10 mph you are driving so if you are going 50 mph, stay 5 car lengths behind the car in front of you.

The simple answer is:: "Far enough that you can brake in an emergency without hitting the car in front of you." *IF* you hit the car in front of you, even if it stops suddenly due to an accident that IT is involved in, then YOU are responsible for that impact and whatever damages result. *** My "rule of thumb" is: at least one semi-length in good weather / on dry roads, two semi-lengths on wet roads, and use your experience to judge distance on snowy/icy roads.

It depends on your speed.