Gradual lane changes and exact lane and sensor events

The core of lane based simulation has a few issues:

• Because gradual lane changes were not properly implemented, we resorted to instantaneous lane changes. For detailed studies on trajectories and safety indicators, this is insufficient.
• When to trigger enter-lane, leave-lane and trigger-sensor events is based purely on 'along the design line' logic. Moreover, enter-lane events are issued at the start of an operational plan, rather than when the front actually enters the lane. This results in unclean trajectory data.

A solutions needs to be found and implemented to issue events at exact moments, and to allow gradual lane changes.