Skyhammer popping up far more than normal
You will remember halted traffic more than the normal traffic speed, as there is no reason to remember normal traffic. You spend more time thinking about being halted in unusual traffic than not thinking about being in normal traffic.
If you think traffic is always heavy, you might tend to even more often remember the heavy traffic and forget normal traffic.
If you flip a coin 100 times, you will often wind up with streaks of 6 heads or 6 tails, not what we think of as “pure randomness”, which would be perfectly distributed.