Prepositions connect words and groups of words together. They express the relation between living beings, things or contexts.

To describe how to get somewhere, you need to use location prepositions, in other words, prepositions that indicate spatial relations, such as the location of a place or the direction. These prepositions answer the questions "Wo?" (where?), "Woher?" (from where?) or "Wohin?" (to where?).

Examples:
Fahren Sie die Straße geradeaus bis zur Tankstelle.
Biegen Sie links ab, und fahren Sie dann durch den Tunnel.

"bis" is a preposition that indicates the end of a movement. When used as a location preposition, "bis" is special because it can only stand on its own in conjunction with locations that don't require an article, for example the name of a place.

Examples:
Wir fahren nicht bis Hamburg, wir steigen in Hannover aus.
oder: Wir fahren nicht bis nach Hamburg.

When "bis" precedes other nouns, it needs another preposition. The second preposition governs the case.

Examples:
Fahren Sie bis zur Tankstelle. (Drive to the gas station. / Dative)
Mit dir fahre ich bis ans Ende der Welt. (With you I´d travel tot he end of the world. / Accusative)

"durch" is a preposition that describes a movement that involves crossing or passing through something. It always requires the accusative case.

Examples:
Fahren Sie durch den Tunnel. (Drive through the tunnel.)
Durch diese Tür kommen Sie ins Aufnahmestudio. (Go through that door to get to the recording studio.)
Harry geht durch den Park ans Rheinufer. (Harry walked through the park to the shore of the Rhine.)

More:

Contractions of prepositions and articles
Some prepositions can be merged with the definite articles they precede to form a contraction.

Here is a chart of possible contradictions: