I’ve noticed this a few times in the last year or so but haven’t been able to figure out the reason. Driving down the highway, two lanes in the same direction, construction up ahead in, oh let’s say the right lane. Instead of merging traffic into the left lane, what they do is close the left lane and merge traffic to the right, then once it’s down to one lane it switches over from right lane to left.
My suspicion is that it is somehow safety related, but the why is not obvious to me.
From what you’re describing it pretty much forces a slow down.
Faster traffic (in the left) has to merge into slower traffic to the right and then the lane change back to the left is likely to cause an additional slowing.
Is it possible there was construction on the oncoming side as well, diverting oncoming traffic into your left lane or even that there’s construction in the left lane? In either case, it could even be that the construction wasn’t actively happening right then, but maybe there was something going on or there’s plans to work there in the next day or two.
Trucks and other large vehicles will be predominantly in the right lane, and it is more difficult for them to merge into the next lane. Closing the left lane allows the trucks to stay where they are.
This sounds like a plausible explanation for merging right.
But if the opposite were true, I could offer an equally plausible explanation: all routine merges are to the left at on-ramps, so we are more accustomed to merging left; and the driver is sitting on the left side with a clearer view of the lane he is merging into (although you could turn this around again - maybe it’s more important for the driver in the lane being merged into to see clearly that someone is trying to merge and allow a gap).
So I question whether what the OP’s has observed is definitely normal practice and/or whether it’s safety-related. There seem to be a lot of possibilities here.
But I’ve also seen them merge left first and then switch back to the right.
The first time I remember seeing this, they had the entire eastbound side closed for work on an overpass, so EB/WB were both taken down to one lane, then EB was brought across the median to use one of the WB lanes. The EB closure was normal - merge traffic to the left, then take that one lane through the median, then back across after the construction. But WB they merged traffic left, then brought the one lane back to the right so EB could use the left lane.
They did this in my city when the freeway was expanded from two lanes to three lanes. The rational was to catch inattentive drivers, especially drunk drivers; it’s hard to navigate the double curves. They reportedly caught quite a few drunk drivers, more than I expected.
I’m skeptical that this was the explicit rationale. It seems like a very bad idea to try to catch drunk drivers by creating deliberately difficult driving conditions that might cause them to crash. If I’m an innocent victim, I’m not just going after the drunk driver, I’m suing the police department (or whoever in the city is responsible for the plan).
It might have not been the original reason for the lane switching like the OP describes (slowing traffic was a big part of this), but I recall the authorities were surprised at the number of drivers who couldn’t mange the double curves and ended up writing many more DUI tickets than normal. It was 30 years ago, so I’ll see if I can find the original newspaper articles.
Yup - probably if the intent was generally slowing traffic for safety reasons, and it ended up catching out drunk drivers, the city would be fine. Otherwise I guess you could claim that any traffic calming measures increase the probability that a drunk driver will crash. And we can’t design our road system around that thought process.