The construction zone warning distance I have seen around here on the Interstate is usually 1500 feet. I have never seen such a sign two miles in advance. Usually a large electric sign with bright, flashing arrows will be used to help guide cars into the open lane. I usually just try to merge as soon as I am aware of the construction up ahead. I’d rather get in the correct lane as soon as I can so I don’t have to deal with problems from uncooperative motorists upon approaching the merge. If I happen to see someone who needs to get in I’d rather be cooperative and let him/her in to avoid causing an accident. If he’s been an ass and trying to race ahead of the pack I’m usually not as willing to slow down to let him in.
For the curious, there was a thread about this a couple of months ago, with opinions all over the map from “merge immediately when you first see the sign” to “merge at the last possible moment.”
Myself, I usually try to stay in the lane-to-be-closed for a while (say until 1/4-1/2 mile from the lane closure), and then merge at the first point where there’s a decent gap.
By the way, dwc, on particularly busy interstates or other highways, it’s quite common for such signs to be placed as much as two miles in advance. (One example, which I’ve passed recently, is the construction zone on the westbound I-87 before the Tappan Zee bridge, north of New York City.)
I hate merging into crowded traffic lanes, so I do it as soon as I see the first sign. Also, as someone had to let me in (or would’ve if I managed to hit a sweet spot), I try to let at least one person in ahead of me.
I realized this after I posted. I should have clarified that the first warning signs for a construction zone is about two miles out from where it actually begins. The warning to merge, however, is usually placed about 1500 feet back from the beginning of the zone.
It depends. CALTRANS has taught me that, if it’s a construction sign that says “lane closed ahead”, I wait until I see that the lane is, indeed, actually closed ahead, as 8 times out of 10 it isn’t.