If a highway has two lanes, the average speed in the left lane is higher than the average speed in the right, but the only major passing opportunities are on the right when there's an empty stretch (because no one merges right).

If a highway has >2 lanes, the left is never consistently the fastest moving lane, and almost every passing opportunity comes from moving right. It is not uncommon to find the right lane near empty, and it is then possible to blow by everyone in that lane.

The exception to the above is in areas with heavy merging, wherein the average American driver seems to not understand how to merge (either blocking one another, or coming to a stop as the merge lane begins). In this case, speed seems to increase moving left.

I, too, have noticed that people here tend to just pick a lane (usually the left one to avoid trucks) and stick to it no matter the speed they're going. However, my experience in the other two states I've lived in (Florida, Indiana) and the other 35+ states I've visited, is that most people in the US know that the left lane is for passing and are somewhat more considerate about this.

Drivers have trouble merging in all 50 states, though. Half the people merge as soon as possible, thinking it's more polite to merge sooner rather than later (or just not wanting to fight for an opening or get angry looks from people who believe merging early is better), and half the people merge as late as possible, attempting to do the zipper merge which is actually the most efficient means of merging and what everyone should do.

Autos with trailers and trucks (vehicles subject to the 55mph limit where other vehicles have a 65 or 70mph limit) are not generally restricted to the right lane in California.

They only are restricted to the rightmost lane on roads where: (1) where there is no other designated (by sign) set of lanes for such vehicles, and (2) The road is not a divided highway with four or more lanes in the direction of travel (where the default, without a designation, is that they are restricted to the two rightmost lanes for normal traffic, plus the next lane out for passing.)

On a road with 1 lane per direction, trucks being restricted to the right lane except for passing has no negative impact on your preferred practice regarding use of the left lane in multilane roads.

On a road with 2 lanes per direction, trucks being restricted to the right lane except for passing exactly matches your preferred practice, though the lower truck speed limit (independent of any lane restrictions) might arguably encourage other drivers to stick in the far left lane (though, except in areas with high density of trucks, doesn't really provide any strong incentive not to follow the use the right lane for traffic, except for passing, it just increases the likelihood that non-truck traffic will want to pass trucks, which is pretty high in any case.)

The lane discipline which doesn't apply on roads with 4+ lanes in one direction thus is really even potentially even a factor in what you are concerned with on roads with exactly 3 lanes per direction.

I've started calling the first merge style you've observed the "Minnesota merge". I deal with it on the way to and from the office, each direction with a good mile of merge lane.

Ninja Edit: Jersey is the best for clear right lanes. I've made entire journeys never coming up on anyone in the right lane, unless they were in the process of "merging", which in this case means getting all the way into the left lane immediately.

I remember being taught this when I started driving in the 90's. And I remember people following it until the mid/late 2000's. It's as if a switch was flipped, and nobody cared about this practice anymore.

I think it's an attitude thing. As often as I see drivers in my area blowing through red lights and pulling other ridiculous or dangerous stunts every single day, I can only imagine it's due to a lack of care or respect on the drivers' part.

The reality is that cars are becoming very ineffcient methods of transport. Most carry only one driver, take up a lot of space, etc. The days of driving on a rural highway with two lanes and having the left lane designated as just the passing lane are long behind us. We don't have the capacity for that outside of rural areas and as more areas become congested with car traffic, the less polite people will be.