It took a number of decades for planners to face destructive consequences of urban sprawl e.g. excess of fuel consumption triggered by long-distance intercity motorways, inefficient and wasteful methods of energy distribution, segregation and associated social problems, fast pace of of deforestation, threat on wild life and accelerating consumption of natural resources. As a reaction, a large number of planning authorities around the world, specifically those in middle-sized cities where environmental measures have traditionally been substantial to decision-making procedures have recently headed towards densification and building inwards as a high planning priority.
The star-shaped city of Stockholm is in fact a very fitting example in this context with numerous plans for urban densification including reconstruction of brown- and grey fields, developing the city in the third dimension and utilizing unused lands close to the city center for construction of new districts. The ongoing urban project of Hagastaden is one example.
By 2025, the area Norrastationsområde will be developed into a new district - Hagastaden including residences, parks, shopping premises, research centers and health facilities. Out of the total 96-ha land area allocated for the project, 30 percent is located in Stockholm municipality and the the rest in the neighboring Solna. 5000 new residential units and 36000 new workplaces will be constructed as part of the project and a number of motor- and railways including E4 and E20 will be placed into underground tunnels and pass beneath the district. The municipality of Stockholm will be responsible for a 10-billion-Swedish-Crown share out of the overall 50-billion expenditures including five billion Crowns for E4/E20 underground tunnels. Hagastaden is primarily characterized as a world-class research and innovation center for life science and health care. The New Karolinska Solna medical university and hospital (inauguration 2016) will be integrated to the project.
Sources:
http://insynsbk.stockholm.se/Byggochplantjansten/Pagaende-planarbete/PagaendePlanarbete/Planarende/?journalnumber=2009-02013
http://www.stockholm.se/Fristaende-webbplatser/Fackforvaltningssajter/Exploateringskontoret/Ovriga-byggprojekt-i-innerstaden/Norra-Station/
http://www.nyakarolinskasolna.se/
http://www.stockholm.se/-/Nyheter/Trafik--Stadsmiljo/Hagastaden--intunnlingen-av-E4E20-har-paborjats/
http://www.google.se/imgres?imgurl=http://www.dn.se/images/2010/12/22/Hagastaden660.jpg&imgrefurl=http://www.dn.se/sthlm/hagastaden-ska-satta-halsan-framst&usg=__W3eQ_S09XxG1J6sHBDlcRHtbSFU=&h=396&w=660&sz=80&hl=sv&start=2&sig2=DlsjAh31i2zbp9CrT__cbQ&zoom=1&um=1&itbs=1&tbnid=LxwZvwy7u0yAVM:&tbnh=83&tbnw=138&prev=/search%3Fq%3Dhagastaden%26um%3D1%26hl%3Dsv%26sa%3DN%26biw%3D721%26bih%3D766%26tbm%3Disch&ei=InQcTruJM43csga5yJzgBg