Inside, Outside, Near Lane, Far Lane, whatever...

[Carol]

Geoff wrote:
> I missed part of your sentence so I shall now rectify that. <snip>
> Allow me to give you a short lesson on the UK road classification
system. 
<snip>

Carol responds:
Thankks for the lesson on road classification in the UK, which was not
at all boring. The A and B classifications make perfect sense, and I
think that I understand what a "trunk road" is--an important road that
isn't a freeway, as we would call it, because it's not "fully
segregated. Would a "trunk road" have traffic lights and
intersections, then? I think it might correspond with a U.S. highway,
which has long stretches between towns where the traffic is
"segregated" by a median, but also stretches with traffic lights when
it passes through a town. (If you want to bypass the town, you take
the Interstate.)

Geoff:
> In 1959, the first motorways were opened; I believe these would 
correspond approximately to the US Interstates. They are fully
segregated dual carriageways - at least four lanes (two each side)
with a central reservation, <snip>

Carol:
Probably. The Interstates are undoubtedly much longer, though, as they
extend clear across the continental U.S. (or from the Canadian border
to the Mexican border going north/south). East/west routes have even
numbers; north/south/routes have odd ones (though, confusingly, I-10,
which extends from Santa Monica, California, to Jacksonville, Florida,
has a long (120-mile) north/south stretch between Phoenix and Tucson,
and I'm sure that other interstates have similar stretches, at least
in the sparsely populated western states. I-40, which runs from
Barstow, California (one of the most desolate places in the world, or
at least it was when I had to go through it as a child or stay in the
awful old motels they had then) to Wilmingon, North Carolina, goes
right past Flagstaff, Arizona, where I grew up. Of course, many people
would take the exit into the city since the next town of any size in
either direction is about fifty miles away. I meant to say that I'40
runs nearly straight east and west at a latitude of 35 degrees North,
and for much of its length parallels the legendary Route 66, the
subject of a song and a 1960s TV show:

http://en.wikipedia.org/wiki/Image:Interstate_40_map.png

http://en.wikipedia.org/wiki/Image:Route_66_map.PNG 

Geoff:

They have grade-separated interchanges, hard shoulders for emergencies
and dedicated service areas.

Carol:
"Dedicated service areas"???? I'm getting a headache: UK government
jargon is as bad as ours in the U.S.

Geoff: 
> Many important A roads have been upgraded but do not always have
full segregation or dual carriageways. <snip>

Carol:
"Dual carriageways" means two lanes going the same direction, so a
road with dual carriageways would have four lanes, right?

Just for fun, as I was thinking about driving all over the UK in
comparison with even attempting a similar feat in the U.S, I did a
Google search to find out which U.S. state the UK most closely matches
in total area. Unfortunately, the results were quite literally all
over the map (England alone can't simultaneously be the same size as
Alabama, Michigan, Oregon, and Rhode Island!). I decided that a
comparison of actual land area would be more accurate:

Great Britain: 94,200 square miles
Arizona: 114,006 square miles
Continental U.S. (excluding Alaska and Hawaii): 3,787,000 square miles

Carol, wondering whether Geoff knows that London Bridge is now in Arizona