In 2004, women's life expectancy exceeded men's life expectancy by 5.2 years, the smallest gender gap in life expectancy since 1946. Life expectancy for whites was five years greater than that of blacks. Life expectancy for black and white men and women was as follows: 1  Black male: 69.8 years.  White male: 75.7 years.
But, that's not always the case. Safe following distances vary according to traffic speed and weather conditions and according to the type of vehicle you're driving. In good conditions, you should allow 2 seconds between your car and the vehicle in front of you. Here's an easy way to work that out.
Instructions. Determine the speed the car is traveling--the higher the speed, the greater the braking distance. For this example, a speed of 70 miles per hour will be used. Establish the stopping distance. This is the distance from your car to the object in front of it. To estimate stopping distance when driving, remember that the average car length is 15 feet. So four car lengths is roughly equal to 60 feet.