Expand Arm Geometry and click on the Entry tab.
The Design Speed is the speed at the yield line.
Entry Lanes refers to the number of designated lanes at the entry point. Select a value from the drop-down list.
The Entry Lane Width (Single) refers to the permitted lane width when there is only a single lane at entry. This is measured between the nearside and offside definition lines.
The Entry Lane Width (Multiple) refers to the permitted lane width when there is more than one lane at entry. This is measured between lane separator lines or between lane separator lines and definition lines in the case of the nearside and offside lanes.
The Flare Lane Length is the distance over which the entry road width changes as it adjusts to accommodate the additional lane. This is normally a significant positive value to avoid a severe step in the nearside definition line.
The Flare Lane Taper Length Ratio is the length of the section where the road widens to allow for the flare lane (flare taper) based on the ratio of the width of the flare lane.
The Flare Lane Width is the permitted width of any extra lanes and determines when extra road markings start.
The Nominal Overall Road Width is calculated as the number of Entry Lanes multiplied by the Lane Width (Multiple) plus the Flare Lane Width where the Flare Lane Length is not zero. If there is only one lane, the value from Lane Width (Single) is used.
Select Equal Spacing Between Lanes to even out the lane width.
The Longer Inner Lane Line defines which lane is longer (outer/inner) when adding extra lanes.
By default the ICD yield line is curved. To set a straight ICD yield line, select Straight Yield Line.
Some standards require individual lane yield lines set back from the ICD and roughly perpendicular to the lanes. Select Lane Yield Line if you require such markings.
If this exit is not relevant to flow calculations, e.g. it might be a service road, then select Ignore in Capacity Calculations.
In all cases the Max and Min values represent the limiting values from the adopted design standard and the Default value will be used when the roundabout is first placed. A default value MUST be provided but Max and Min may be blank if there is no limiting value.