Roundabouts are a Primary Safe System solution for passenger vehicles because of their effective reduction in death and serious injury. However, at multi-lane roundabouts the second circulating lane can create vehicle exiting conflicts. On roundabouts with more than four legs and/or with legs aligned at significantly less or more than 90deg, it can be difficult for drivers to determine to which legs the pavement arrows are pointing.
There are a variety of roundabout design features that lessen the chance of exiting crashes. These include:
◻ Geometric alignment of entering legs to 90deg
◻ Consolidating entering legs to four approaches
◻ Rationalise lane allocations if traffic analysis allows
◻ Alberta line marking (spiral linemarking)
◻ Clear directional signage
◻ Angling approach line marking to more accurately reflect the layout