One of the things that seems to be a constant issue on our roads is the lack of space between vehicles traveling in the same lane.
We like the Peter Brock (RIP) method with this and that is to be 3 seconds behind the vehicle in front. This is a good distance that allows enough reaction time for evasive action should it be required. So regardless of your forward speed you need to leave a space that would take 3 seconds to travel if the vehicle in front suddenly stopped.
One of the biggest issues on our freeways is congestion during peak traffic. But a lot of this congestion could be avoided if drivers left more space to the vehicle in front. This has the effect of smoothing out the stops and starts of the traffic by allowing more gentle adjustments to speed fluctuations.
It also makes lane changes and mergers smoother.
If you have left enough space to the vehicle in front of you and another vehicle indicates to change lanes in front of you simply adjust your speed to allow more space, re-access your 3 second gap and everyone is happy with no stopping and starting. Even if you are moving slower than the maximum speed limit at least you are moving at a reasonable pace. The more this is done the more it will become common place, as the number of vehicles on our roads increases every year these sorts of strategies  are becoming more important.
Julia Osredecki
Well without not knowing this I always stay a full car size and a bit between me and the car in front of me I guest is about of 3 seconds? ? and wish that evrerybody did that but…