Best cross-country route in TTR USA?
Please note: This answer is predicated on the use of the 1910 expansion pack. The analysis for which tickets are available for which route will not be valid for the "vanilla" Ticket To Ride: USA game, but the other elements of analysis (which routes are easier to build, get more points for building the routes themselves) will still be of value.

On a basic level, each of the four cross-country routes executes the same game plan: get across the country to connect as many high-value tickets as possible. There are of course other game plans, but if you wanted to use a cross country route, here is some advice.

Some ways to analyze our options are:


The number of turns it takes to build all of the lines (if it takes fewer turns to lay down the trains, then you can use more turns for picking trains, getting tickets, etc.)
The value of the trains for the lines (the actual value of building the trains themselves)
The number of trains it takes across the country (higher can be better because it helps get the longest train card, however lower can also be advantageous because you need to collect fewer train cards, and gives you more trains to do other building with)
The tickets that you can potentially complete using said route -- for example, if you can get Los Angeles to New York, you can get Los Angeles to Chicago relatively easily (but only if take the central route)


Depending on what you want to prioritize, the routes will be appealing to different amounts.

Before attempting to analyze the routes, here are the routes themselves:


Northern Route: Vancouver-Calgary-Winnipeg-Sault St. Marie-Montreal-New York (alternately, the so-called "more southernly northern route": Vancouver-Calgary-Winnipeg-Sault St. Marie-Toronto-Pittsburgh-New York)
Mid-Northern Route: Seattle-Helena-Duluth-Toronto-Pittsburgh-New York
Central Route: San Francisco-Salt Lake City-Denver-Kansas City-Saint Louis- Pittsburgh-New York
Southern Route: Los Angeles-El Paso-Houston-New Orleans-Miami


Number of turns


Northern route: 5 turns to build (vs. the "southernly northern route": 6 turns)
Mid-northern route: 5 turns to build
Central route: 6 turns to build (via Chicago: 7 turns)
Southern route: 4 turns to build


Value of trains


Northern route: 51 points (vs. the "southernly northern route": 43 points)
Mid-northern route: 49 points
Central route: 35 points (via Chicago: 31 points)
Southern route: 49 points


Number of trains it takes to cross the country


Northern route: 23 trains
Mid-northern route: 22 trains
Central route: 21 trains
Southern route: 20 trains


Tickets that can be completed

To assess this, we can see which tickets are completed within the route itself (i.e. you don't have to do any additional work - if you get the route, you can get the ticket) and those which are easily completed if you get the route (i.e. if you build a couple more times, you can get the ticket).

Also, the question of which tickets can be completed is predicated on which ones you actually get. So in a game with fewer players, of course you have a better chance of getting the specific tickets you want. You also have to be prepared to spend many turns taking tickets and hoping you get the right ones - which is why no strategy is foolproof. You can always just get the wrong tickets.

Northern Route

Tickets completed within the route itself:


Vancouver-Montreal (20 points)


Tickets easily completed from off of the route:


Seattle-New York (20 points, requires 2 extra routes)
Vancouver-Duluth (13 points, requires 1 extra route)
Vancouver-Denver (11 points, requires 2 extra routes)
Portland-Nashville (17 points, requires 4 extra routes -- yes, this one is a long shot -- unless you use the "more southern" option that goes through Toronto and Pittsburgh, in which case it only requires 2 extra routes)


Mid-northern route

Tickets completed within the route itself:


Seattle-New York (20 points)


Tickets easily completed from off of the route:


Portland-Pittsburgh (19 points, requires 1 extra route)
Vancouver-Duluth (13 points, requires 1 extra route)
Denver-Pittsburgh (11 points, requires 1 extra route)
Chicago-New York (5 points, requires 1 extra route)
Vancouver-Montreal (20 points, requires 2 extra routes)
Seattle-Oklahoma City (14 points, requiers 2 extra routes)
Vancouver-Denver (11 points, requires 2 extra routes)
Portland-Nashville (17 points, requires 3 extra route)


Central route

Tickets completed within the route itself:


Denver-Pittsburgh (11 points)
Salt Lake City-Kansas City (7 points)
Denver-Saint Louis (6 points)


Tickets easily completed from off of the route:


Salt Lake City-Chicago (11 points, requires 1 extra route, unless you reroute through Chicago)
Chicago-New York (5 points, requires 1 extra route, unless you reroute through Chicago)
San Francisco-Washington (21 points, requires 1 extra route)
Las Vegas-New York (19 points, requires 1 extra route)
8 Portland-Pittsburgh (11 points, requires 1 extra route)
Kansas City-Boston (7 points), requires 1 extra route)
Seattle-New York (20 points, requires 2 extra routes)
San Francisco-Atlanta (17 points, requires 2 extra routes)
Portland-Nashville (17 points, requires 2 extra routes)
San Francisco-Atlanta (17 points, requires 2 extra routes)
Chicago-Santa Fe (9 points, requires 2 extra routes, unless you rereoute through Chicago)
Chicago-Boston (7 points, requires 2 extra routes)
Los Angeles-Atlanta (15 points, requires 3 extra routes)
Seattle-Oklahoma City (14 points, requires 3 extra routes)


Southern route

Tickets completed within the route itself:


Los Angeles-Miami (19 points)


*Tickets easily completed from off of the route:*


Las Vegas-Miami (21 points, requires 1 extra route)
Los Angeles-Atlanta (15 points, requires 1 extra route)
Los Angeles-Oklahoma City (9 points, requires 1 extra route)
San Francisco-Atlanta (17 points, requires 2 extra routes)
St. Louis-Miami (8 points, requires 2 extra routes)

What does this tell us?


The Northern route via Montreal is perhaps the most out-of-the-way route: there are not a huge number of tickets to complete if you keep to the top of the board. However, if you compromise on using long trains only, and go Sault St. Marie-Toronto-Pittsburgh-New York instead of Sault St. Marie-Montreal-New-York, you have more potential tickets, because many tickets stop in Pittsburgh

The mid-northern route completes very few tickets in and of itself. However, off of this route there are a great many "high value" tickets which can be completed. This also means that there isn't as much competition for it, both because it consists of so many 6-train routes (and none of them are gray!), and because relatively few tickets go to Helena, Duluth, or Toronto.

The central route has the most versatility, due to the fact that it is in the middle of the board and so you can build off of it in both northern and southern directions.

The southern route is perhaps most difficult to complete, because the Houston-New Orleans route can be taken easily, and is highly valuable. If you choose this route, take that quickly; but it may give away your strategy.

The southern route clearly has the highest route points per turn necessary to build the route, and can be built quickly. So the southern route works best in conjunction with another strategy, such as building up the east coast (which gives access to many other tickets such as Los Angeles-New York, etc).

If you choose the central route, going through Chicago will get you more potential tickets, but you will lose a turn and 4 points by building two routes (St. Louis-Chicago and Chicago-Pittsburgh) rather than the single St. Louis-Pittsburgh route.

Though it is the most versatile (and can be completed even if there is competition over it, due to the double-routes), the central route has a number of downsides. It takes many turns to build, which reduces the number of chances to take tickets - a central element to the basic strategy of trying to complete as many tickets off of your main route. In addition, it is worth far fewer points in and of itself. Especially if you go through Chicago, in which case you both lose a turn building, and there can be a 20 points difference between the central route and the northern route! It is also the most visible of the routes -- since it has so many double routes -- and so people gravitate towards it and it is highly contested.

Plus there's the element of luck. You can't quite just pick a strategy and get the tickets you want. In many ways the appropriate strategy is based on the random tickets you get at the beginning if the game.

In the end, the routes are very balanced - as one would expect from a game which exhibits such high replay value.