E4 through Sweden

The E4 is Sweden's most important highway, passing through or by fifteen of Sweden's thirty largest cities, most of them being historically important. It is the second longest road within a single European Union country, behind the E45 between Gothenburg and Karesuando; the E6 through Norway is much longer, but outside the EU.
E4 is also used by Norwegians to drive between Finnmark and Southern Norway, considerably shorter than E6.
The leg between Helsingborg and Stockholm used to be served by Riksväg 1, "Riksettan" ("National Road 1") before the E-number introduction 1962, then with very little motorway.
The E4 is a remnant of an obsolete route numbering standard. With current standards, longitudal highways should have odd numbers. The E4 was to be part of E55, which stretches from Kalamata in Greece to Helsingør in Denmark. Due to the cost of sign replacement, and tradition, Sweden has got permission to retain the numbers E4 and E6.
Most of the E4, except in Norrland, is limited-access highway (motorway in British English). E4 in Norrland is often 2+1-road with a middle barrier and grade-separated exits.
National rail carrier SJ runs rail traffic parallel to the E4 (often some distance away from it), from Malmö to Stockholm, and onwards from Stockholm to Luleå.

• Ferry from Helsingör or Copenhagen to Helsingborg.
• The Öresund Bridge from Copenhagen to Malmö, and E6 to Helsingborg.

To travel north to south, go to Tornio in Finland, and cross the border. The E8 connects Tornio to Tromsö.

Scania

• HelsingborgGateway to the continent, famous for the Kärnan castle, and a successful football team.

• Örkelljunga

Småland

• Markaryd
• Ljungby

• Värnamo

• JönköpingA quaint city, nicknamed the "Jerusalem of Sweden" for its many churches. Famous for production of Swedish safety matches.

• GrännaOne of the most scenic parts of the E4 is at lake Vättern. There is a rest area at Brahehus, a Medieval ruin.

Östergötland

• Ödeshög

• Mjölby

• LinköpingA city with a cathedral, a university, and the birthplace of Swedish aviation.

• NorrköpingAn old industrial city.

If you travel to or from Norrland, you should avoid passing through the congested highways in Stockholm at least in rush hour, and instead use roads 50, 55 or 56 through inland Sweden. These roads are non-expressways. Traffic is usually lighter.

Södermanland County

• NyköpingAn old city with the Skavsta airport.

Stockholm County

The E4 through Stockholm can be congested all the way between Södertälje and Arlanda, especially at rush hour in mornings and late afternoons. The passage through Stockholm requires congestion tax (see Stockholm#Get around).

• SödertäljeA port city, and the uncrowned capital of the Assyrian diaspora.

• Salem, Botkyrka, HuddingeStockholms southern suburbs, with the world's largest IKEA store.

• StockholmSweden's capital and largest city. The highway gives a scenic view of the inner city, especially for the lanes heading north.

• Solna and KistaStockholm's northern suburbs. The E4 passes by Friends Arena (the national football stadium) and the Kista Fairs.

• Sollentuna, Upplands VäsbyStockholms far-north suburbs.

• Sigtuna and Stockholm Arlanda AirportSigtuna is a millennial city, and Sweden's capital during the Middle Ages. Arlanda is Sweden's largest airport.

Uppsala County

• Knivsta

• UppsalaHome to the largest Nordic cathedral, and the country's first university.

• Uppsala countryside

• Tierp

• ÄlvkarlebyA waterfall and the Chinese-styled Dragon's Gate Hotel.

Gävleborg County

Though the coast of Norrland is known for its natural beauty, much of the E4 stretches through inland forest. If you have time, consider driving along smaller roads along the sea instead.

• GävleA port city, at the gateway to Norrland. Its main claim to fame is the Christmas goat that tragically attracts arsonists almost every year.

• SöderhamnA town of 11,000 inhabitants.

• Hudiksvall

Västernorrland County

• SundsvallCentre of the Swedish wood industry.

• Timrå

• HärnösandA coastal city.

• High CoastUNESCO World Heritage Site.

• Örnsköldsvik

Västerbotten County

• Umeåthe largest city of Upper Norrland.

• SkellefteåAn industrial city.

Norrbotten County

• Piteå

• LuleåDominated by the iron and steel industry.

• Kalix

• HaparandaSweden's easternmost city, with the world's northernmost IKEA store.

• Tornio

The E4 is more known for convenience, than for its beauty. Much of the distance goes through repetitive forests, except some legs; north of Jönköping there is an astounding view of lake Vättern, and the passage through Stockholm is great, provided you don't get stuck in a traffic jam. If you have plenty of time, you should consider parallel routes (but check out which one to use, or you might see forests anyway)

Cross the border to Tornio.
E4 is preferably used for at least one of the directions when visiting Norrbotten, Finnish Lapland or Finnmark.

See driving in Sweden. Winter driving and animal collisions are significant risk factors, especially in the north.