RODEL is based on research and field observations taken by the Transport Research Laboratory (TRL). This includes investigation of approximately one million vehicles at 86 roundabout sites during 11,000 minutes of "at capacity" operation. Study results are summarized by lead researcher Dr. Rod Kimber in The Traffic Capacity of Roundabouts (TRL, 1980).

RODEL licenses the equations developed by this research directly from the TRL for use within the foundation of RODEL. The software also incorporates major advances made in the roundabout design field, including environmental and economic constraints, to create a diverse package of useful tools for engineers and planners.

The following pages describe many resources explaining and supporting the methodology of RODEL and its strong foundation in statistically robust sampling of field observation.