The Bay Area has more than 1100 motorcycle crashes on freeways per year. Of those, 22% are rear-enders caused by the motorcyclist. If you think about following distance in terms of "car lengths" you could be next.
Space cushion gives you the
time you need to react to sudden, unexpected braking, but at 60mph a given time corresponds to twice the distance as at 30. That's why the two-second rule is taught in driver and rider ed.
Of course, a two-second gap at 60mph--176 feet or 11 car lengths (Accord, Camry, etc.)--on a Bay Area freeway while commuting will soon be occupied by a space-cushion thief, possibly putting you in greater danger with a hasty swoop. So as a practical matter, you must sometimes settle for less.
However, you still need time to react to a sudden slowdown. You can get that time with a clear view to traffic beyond the vehicle ahead of you. If you can react to the same event at the same time as the driver ahead, you reduce your need for space cushion. Instead of 2 seconds, 1 second may be adequate--IF YOU'RE PAYING ATTENTION AND PREPARED FOR IMMEDIATE ACTION.
If, however, you're behind a vehicle you can't see over, around, or through, you NEED that 2 seconds. In a sudden slowdown, you will be reacting not to the event that triggered the driver ahead, but to his reaction to that event.
BTW, don't fool yourself that your godlike braking skills and the track tires you had on warmers before heading out for work will give you an advantage. Today's ABS-equipped cars brake very well. And importantly, they get to max deceleration quickly, because they don't have to transfer weight forward to achieve best braking.
From a
7-year-old post:
The Top Ten Things I Like About Following Distance
- It compensates for reaction deficit. When traffic slows suddenly, it gives me time and space to react and avoid a rear-ender.
- It compensates for attention deficit. Even if my attention is momentarily diverted when traffic slows suddenly, it still gives me time and space to react and avoid a rear-ender.
- It compensates for braking deficit. If the vehicle ahead can brake more effectively than I, it gives me more space to slow.
- It improves my forward field of view. The farther I am behind the vehicle in front of me, the smaller the visual obstruction to traffic ahead.
- It eases traffic transitions for others. When streams of traffic are converging or diverging, it gives other drivers room to merge so they're less likely to cut me off.
- It eases traffic transitions for me. When I'm entering a new flow, it gives me more options when choosing a place to merge safely.
- It enables me to spot debris. If the vehicle ahead of me runs over something, it gives me time and space to react when the hazard becomes visible to me.
- It allows me to compensate for a tailgater. If I'm being tailgated, it reduces my braking requirement in the event of sudden slowing and, thus, the risk of being rear-ended.
- It allows me to gap a tailgater. If I need to slow to make a turn or enter a driveway, it gives me room to accelerate briefly and gap a tailgater, giving him more time and space to react to my slowing.
- It helps me avoid someone else's crash. When riding in a group, it gives me time and space to react and avoid joining the stack of motorcycles if someone screws up.