How to decode Denmark's old-fashioned motorway names

At  the point it enters the country from Germany, it's the Sønderjyske Motorvej. It becomes the Østjyske Motorvej when it hits Kolding, the Nordjyske Motorvej north of Aarhus, and ends up as the Frederikshavns Motorvej after passing Aalborg, before crossing the Skagerrak to Norway. They're all the E45. 

If you think this is confusing, you should know that this is how the system works after it was simplified by the Danish Road Directorate in 2003, with the directorate giving each stretch an official national name. Until then, different municipalities would frequently have different official names for the same stretch of road.

For newly arrived foreigners planning road trips in Denmark, the road naming system means you need to learn which name refers to which road number before you can have a chance of understanding traffic reports on the news. 

So here are the names for the main roads in the European E-road network (which, it turns out, was developed by the United Nations rather than the EU). 

E20

The E20 enters Denmark from the UK at the port of Esbjerg as Esbjergmotorvejen, becomes the Taulovmotorvejen after it hits Kolding Vest (following a short stint combined with the E45). It becomes Fynske Motorvej after passing the new Little Belt Bridge and then Vestmotorvejen after passing The Great Belt Bridge.

It briefly becomes the Køge Bugt Motorvejen at Køge, turns into the Amagermotorvejen at Avedore, before ending its stay in Denmark as the Øresundsmotorvejen between Ørestad and the Øresund Bridge. 

E47 and E55

The E47 enters Denmark at Rødby as Sydmotorvejen, connecting back by ferry to Puttgarden in Germany.  It then becomes Motorring 3 when it hits Køge Vest. When it hits Østerbro in the north of Copenhagen it transforms into Helsingørmotorvejen, keeping the name until it departs for Sweden at the port of Helsingør, becoming the E4 on arrival in Helsingborg.

The E47 shares the same stretch of road in Denmark as the E55, apart from a short stretch between Rødbyhavn and Eskilstrup on the island of Falster. 

The E55 instead starts at Gedser on Falster (continuing on from Rostock in Germany). 

E39 

The E39 is unusual in having just one name in Denmark: Hirtshalsmotorvejen. The road starts north of Aalborg and goes just 62km to Hirtshals on the northwest coast of the Jutland peninsular. It only really comes into its own on arrival in Kristiansand in Norway, when it follows the entire Norwegian west coast all the way up to Trondheim. 

Other motorways in the Danish national road network

Many of Denmark's motorways aren't part of the the European road network, so you will also hear other motorway stretches named frequently on traffic forecasts. Here are most of the main ones, although there are other, smaller stretches of motorways we have left out. 

Primærrutenummer 15

This starts at Grenaa on the east coast of Jutland as Djurslandmotorvejen. It then becomes Herningmotorvejen between the north of Aarhus and the east of Herning (although, to confuse matters, the final stretch between Brabrand and Herning is often called Silkeborgmotorvejen. 

East of Herning, it becomes Midtjyske Motorvej, and it ends up as Messemotorvejen as it curves around Herning to the suburb of Snejbjerg. 

Primærrutenummer 18

This starts at Vejle, and is called Midtjyske Motorvej up until it reaches Herning, after which it becomes Holstebromotorvejen until arriving in Holstebro on the northwest coast of Jutland. 

Primærrutenummer 21 

This road between Copenhagen and Randers is called Holbækmotorvejen between Valby on the outskirts of Copenhagen and Holbæk, when it ceases to be a motorway. 

Primærrutenummer 16 

This road from Copenhagen to Ringkøbing on the western coast of Jutland is called Hillerødmotorvejen when it leaves Utterslev mose on the outskirts of Copenhagen. It then passes through Farum and ends in Høbjerg north of Hillerød.