THIS WEBSITE IS DEDICATED TO SAFER DRIVING IN TRAFFIC
The concept of a safe gap is relative. All decisions may involve some risk,
but some decisions are safer than others. Safe-gap.com addresses the risk associated
with a driver's decision about how close to drive behind a vehicle in front.
It exposes the 2 second gap rule and the 2 car lengths gap rule to their realities.
Myth: you should leave a 2 second gap between yourself and the car in front.
Much of the time this is good practice but when conditions are adverse it would
be unsafe to be so close.
Myth: you should leave 2 car lengths between you and the car in front. At slow
speed it might, possibly, be a sensible gap; but on a motorway it's positively
dangerous to follow with so little time to react to traffic in front. If you're
doing less than 10mph a gap of 2 car lengths might just result in bent metal.
Try to imagine, when you have a vehicle following you:
can the driver behind see what's in front of you? (the closer they are
the less they can see)
if you stop suddenly would the driver behind run into your rear end?
If you think the driver behind cannot see what's in front
of you OR you think that the driver behind would be unable to
stop if you stopped suddenly, then you already know what's an unsafe
gap .
THE TRAFFIC FLOW ILLUSTRATIONS
SHOW HOW VEHICLES RESPOND TO SPEED AND TRAFFIC DENSITY.
See how compression waves and stop-start motoring occur in dense traffic. You
can set the speed of the front car and watch the following vehicles adjust their
speeds to suit. Also, by setting the average gap between vehicles you can simulate
conditions where drivers are either forced to be dangerously close because of
traffic density, or choose to be too close because conditions seem favourable.
Watch the cars on the moving road to see what happens.
70 vehicles are randomly created between between 2m and 7m long
with most being about 4m long.
Drivers are randomly created to have reaction times between 0.7 seconds and
2.5 seconds with most being around 1.25 seconds. This is the thinking time plus
the time to move between accelerator and brake. Drivers cannot change their
reactions times (not a choice in life), only their desired gaps (possible decision).
Because the vehicles and drivers are created randomly, every time you visit
this website you get a different set of vehicles and drivers. The overall behaviour
of the traffic will be different each time.
The lead car can accelerate at 1.0g and decelerate at 1.0g
All other vehicles can accelerate at 0.2g and decelerate at 0.7g
Drivers do not start braking behind the vehicle in front until they've come
within range. That is, they do not even contempate slowing down if they are
more than 5 times their intended gap.
The maximum speed of the road is 89mph - no vehicles can travel faster than
89mph. This may give an unrealistic illustration at higher road speeds because
following cars can't actually catch the lead car if it's doing 89 mph.
The traffic stream is declared steady when all cars are within 2mph of the road
speed.
