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T.P.D.M.V.2.H
(v)
The vehicle proceeds towards the "Give Way* line on a path whose
centre line is initially 1m away from the nearside channel or
kerb of the approach arm;
(vi) Then either :~
(a) It proceeds towards the central island of the roundabout
passing through a point not less than 1m from the nearside
channel or kerb; or
(b)
"Where a subsidiary traffic island exists, it is assumed to
pass whichever side of the island involves the least
deflection;
(vii)
The vehicle is then assumed to continue on a smooth path with
its centre line never passing closer than 1m from the centre
island»
Based on the foregoing, which is diagrammatically represented in Brg. No*
4*5«A.1, the centre line of the most realistic path that a vehicle would
take in its complete passage through the junction is drawn on a 1/500
scale using a flexicurve or similar. More than one line should be drawn
and the most critical path considered. The entry path curvature is taken
to be the tightest radius over a 20 - 25 m length in the vicinity of the
"Give Way" line (i.e. between X and Y on Drg. No. 4.5.A.1). The radius
should be measured using a suitable template.