It runs roughly west–east through Ireland, the United Kingdom, Denmark, Sweden, Estonia and finally Russia. The length is 1,880 km (1,170 mi).
The road is not continuous; at three points, a sea crossing is required. Roll-on/roll-off ferries make the crossings from Dublin to Liverpool and from Stockholm to Tallinn. No vehicle-carrying vessels traverse the North Sea from Kingston-upon-Hull to Esbjerg (as of 2013).
|West end||Shannon Airport, Ireland|
|East end||Saint Petersburg, Russia|
|International E-road network|
The initial section of the E 20 from Shannon Airport to Dublin via Limerick is approximately 228 km long and is only partially signed, along the M7/N7. The section from Shannon Airport to east of Limerick is mainly dual carriageway, with a short section of motorway as part of the Limerick Southern Ring Road. The Shannon Tunnel, opened on 16 July 2010, completed the bypass of Limerick. The section from Limerick to Naas is motorway (M7), and the final section from Naas to Dublin is dual carriageway (N7). A ferry must be used from Dublin to Liverpool.
E 20 follows the A5080 from Liverpool to Huyton, the M62 from Huyton to South Cave, and the A63 from South Cave to Kingston upon Hull. The route length across the UK is 205 km in total, it is not signposted in the UK.
There is no ferry between Kingston upon Hull and Esbjerg, but Immingham is 48.3 km/30 mi from Kingston upon Hull which formerly had ferries to Esbjerg with DFDS Seaways. Alternative ferries used to also be available from Harwich but that is 350 km/220 mi from Kingston upon Hull. There are no longer any passenger routes operating between UK and Scandinavia.
It passes along the Great Belt Bridge which consists of two parts of 6 + 6 km.
The Great Belt Bridge and Oresund Bridge are tolled, both with more than €30. The Oresund Bridge is 8 km and there is a 4 km tunnel on the Danish side of the Sund. The road crosses the border between DK/S on the bridge.
In Sweden, E 20 is a motorway from the Øresund Bridge in Malmö to Nääs 30 km east of Gothenburg, a 320 km (200 mi) long motorway. Furthermore, it is a motorway most of the route from Vretstorp (20 km (12 mi) west of Örebro) to Stockholm.
The part through Stockholm has very heavy traffic, including the most heavily trafficked road in Scandinavia, Essingeleden (160 000 vehicles/day). There is often congestion on this stretch. A new tunnel for route E20, "Norra länken", was built north of the inner city, opened 30 November 2014. The planned Förbifart Stockholm bypass will divert traffic from Essingeleden.
In Estonia, E20 follows the route of national main road nr. 1 (Tallinn–Narva). In Tallinn to relieve traffic a bridge has been built on the intersection of the E263 and the E20. The E20 across Estonia is partially an unsigned expressway (speed limit 110 km/h in summer), for 80.7 km east of Tallinn to Aaspere along with a section near Haljala (km 87 - 90.5) and a section between Kohtla-Järve and Jõhvi (km 155.9–163.2). The remainder being single carriageway. The distance from Tallinn to the Russian border at the Narva River is 218 km.
In Russia, the route takes the Narva Highway also listed in the Russian road numbering system as the A180 route (formerly known as the M11 route) running from Ivangorod to Saint Petersburg as a dual-line highway. The distance from Ivangorod to Saint Petersburg is 142 km. The border control facilities at the Estonia-Russia crossing are equipped and being operated for a limited amount of traffic on both sides of the border. The border crossing requires a reservation, however the waiting lines still can extend for many hours and even days.