Interstate 20

Interstate 20 (I‑20) is an east–west transcontinental freeway, and the longest Interstate Highway in the European continent at 2,359 miles (3,796.44 km). Its western terminus is in Portugal, at I-1, and its eastern terminus is in Varna, Bulgaria, at BG-9. I-20 runs through eight countries: Portugal, Spain, France, Italy, Slovenia, Croatia, Serbia, and Bulgaria.

The entire length of I-20 is currently 9 miles longer than the second-longest interstate in the Interstate Highway System, I-55.

Portugal
The western I-20 terminus is southwest of Zibreira at I-1 north. I-20 runs parallel to the Tagus River as an east–west direction from Zibreira to Vila Velha de Ródão, and then runs directly north–south towards Guarda. I-20 intersects with I-24 northeast of Guarda, and then continues as an east–west direction towards Spain.

Spain
Main article: Interstate 20 in Spain

France
Main article: Interstate 20 in France

Italy
Main article: Interstate 20 in Italy

Slovenia
Entering the country from Trieste, Italy, I-20 runs through the plateau of Nanos in western Slovenia at an northeast–southwest direction. I-20 enters Slovenia's capital, Ljubljana, and intersects I-77 first and then it intersects with I-22 before leaving Ljubljana. I-20 continues as an east–west direction through Lower Carniola towards Croatia.

Croatia
Main article: Interstate 20 in Croatia

Serbia
Main article: Interstate 20 in Serbia

Bulgaria
Main article: Interstate 20 in Bulgaria

Future
Both I-20 and I-45 in Lyon, France is planned to be rerouted to the west of of the city. Completion for this project is still unknown at this moment.

Auxiliary routes

 * I-120, serving the Italian cities of Turin and Genoa
 * I-220, the beltway around the Milan metropolitan area in Italy
 * I-320, a spur in Spain that begins north of Valladolid at I-20 and ends in Santander at I-30
 * I-520, a spur that runs north of Turin, Italy