30 years ago, Umeå's first roundabout was opened on the then E4 at Coop in Ersboda.
Today, Umeå has around 700 roundabouts that have gradually replaced intersections and red lights.
But the roundabouts can be tricky to get through for heavy transport.
When the expansion of wind power has now picked up speed again, long cars are transported through the city.
Those who are to transport the large and awkward wind turbines must turn to the Swedish Transport Administration or Umeå municipality to get a permit when they want to make changes to the traffic network.
New phenomenon
The phenomenon is quite new, states traffic engineer Sara Olsson, who grants permission to modify traffic routes within Umeå municipality's boundaries.
At the same time, the forecasts for wind power expansion in Sweden show that it will double between 2018 and 2022. Several large parks are being built and planned in Västerbotten and Norrbotten, which will increase transport along the roads.
See what the roundabouts look like and hear the traffic engineer in the clip above.