sidra intersection allows analysis of single-lane and multi-lane roundabouts. it employs a combined (hybrid) geometry and gap-acceptance modelling approach in order to take into account the effect of roundabout geometry on driver behaviour directly through gap-acceptance modelling. sidra intersection software includes templates for roundabouts including all roundabout examples given in mutcd 2009 and trb/fhwa 2010 roundabout informational guide (nchrp report 672). a roundabout metering analysis method allows the evaluation of the effect of metering signals on roundabout capacity and performance. metering signals help to solve the problem of excessive queuing and delays at approaches affected by unbalanced traffic streams at roundabouts. fully signalised roundabouts can be modelled as a network. a recent nchrp survey of us state transport agencies found that sidra intersection is the most widely used software tool in the us for roundabout analysis as reported in the us transportation research board document titled roundabout practice.