It took some getting used to, but over here they generally put a sign telling you that there is construction 1 mile ahead, another for 1/2 mile ahead, and another for 1/4 mile. By then, if you haven't realized you are approaching some construction, more signs probably won't help! What amazed me was how consistent they are about it.
Once, I was driving along one of their back roads and I saw a sign warning of construction 1 mile ahead. I prepared for traffic lights, or whatever else might be there. I passed the sign for 1/2 mile, then the 1/4 mile, and I saw no evidence of traffic problems. A quarter of a mile later, I passed the 'construction'. It was one truck pulled over to the side of the road, and the driver was up a tree, trimming branches.
Even though in this case there was no impact on the traffic, I like the fact that they gave me warning. It makes me feel more in control of my driving, and means I am not faced with surprises around every turn (and they have many turns here).
Not only do they provide advance warning for construction, but they have continued the concept with their exit signs from many of the major motorways. As you approach the off-ramp, there will be signs for ramp in 1 mile, ramp in 1/2 mile and ramp in 1/4 mile (sometimes they give them in yards instead). Not only did that mean I always knew where the next exit was, but I when I started seeing the distance signs I knew it was time to get into the exit lane.
I hope that someday the sense of this will reach North America and they will start giving more advance signs both for ramps and, more importantly, for construction. I'm sure it would help reduce the number of last minute panic lane changes, and for those who try to drive courteously, it would allow them to change lanes early, without having to worry about the lane vanishing.