First, you wouldn't have to "hide" for every car. You can hear what the cars are doing ... there's a difference between driving normally, and "hooning". And on a quiet road in the middle of the night, that difference is quite evident. In all my night riding, I think I've been compelled to "hide" maybe 2 or 3 times.

Second, the amount of traffic depends entirely upon where your route is. I've done rides where there have been a grand total of about 3 vehicles between midnight and 6 am. I've done other rides where there have been a fairly steady stream of vehicles throughout the night (mostly semi-trucks).