Just to tell you their is no route 426 in Pokemon Diamond.

If you are planning a road trip, it is essential that you use a route planner. When you use a route planner, you can input several desired destinations, and the route planner will create a route for you that will take you to all of your desired destinations. Often, you can tell the route planner whether you want to avoid tolls or highways, if these things are important to you. When you use a route planner, you should keep in mind that you will probably end up driving more miles than are actually calculated because you will want to explore the areas a bit. You may drive several miles off of the route to go to a restaurant that locals rave about.

Route 123 is the path that connects Mount Pyre to the area close to Mauville City (Route 118). It can only be accessed by surfing south from Mt Pyre.

1. Take I-10 WEST to San Antonio.

Sinnoh routes are numbered 201 - 230, so definitely there is no Route 113 in Pokemon Platinum. But if you mean Route 213:

- it is a route that contains the Hotel Grand Lake and the Seven Stars Restaurant, in which in a day you may have double battles with a random 5 pairs of trainers. Near it is the entrance to Lake Valor, place of the legendary Pokemon Azelf.