This literature review aims to survey Swedish and foreign design solutions to
meet mainly speed
and accessibility requirements of roundabouts and to see if foreign
experiences are relevant for
Swedish conditions. Great importance has also been given to studying to what
extent there are
"functional categories" of roundabouts.
The survey shows that lower speed and single lane in roundabouts improve
Furthermore that there are good possibilities to control speed through design
e.g. using narrow,
radial entries and exits with small entry radius, entry and exit deflection
to the left, design for an
entry path curvature with small radius and traffic island.
The survey also shows that give way regulations between vulnerable road users
vehicles in Sweden can be made clearer.
The idea of dividing roundabouts and the entire traffic system into distinct
categories" is to improve traffic safety by decreasing the risk of the road
user to misunderstand the
situation. To create good categories of roundabouts it ought to be
investigated what is needed and
how it can be mediated to the road user what function category roundabout he
is in. Several
countries have, just as Sweden, a not very pronounced category classification
Linköping: Statens väg- och transportforskningsinstitut., VTI meddelande 895 , 2002.
Swedish, Sweden, Roundabout, Speed, Accessibility, Traffic lane, Safety, Geometric design, Road user, Recommendations