Roundabout Speed Limits 
Roundabouts should be treated very similarly to ramps.
If there is a regulatory speed limit sign posted on OR for the roundabout itself, this speed limit should be added for all the roundabout segments. In the following example there are different speed limits for various approach/exit streets, but the roundabout has its own speed limit of 20mph. In this example all the roundabout segments should be set to 20mph.
If the speed limit for the segments approaching and departing the roundabout are all identical, then that speed limit should be used for all the roundabout segments as well. In the following example all the approaching, and exiting streets have the same speed limit. In this example all the roundabout segments should be set to 35mph.
If there is no posted regulatory speed limit on or for the roundabout, and there are different speed limits depending on approach or exit, then all the roundabout segments should be set to the lowest speed limit entering the roundabout.