A Runway Incursion Monitoring and Conflict Alert System (RIMCAS) supports air traffic controllers in monitoring and managing aircraft and vehicle movements on an airport's runways and taxiways.

RIMCAS uses data from radar and sensors to continuously calculate the positions of aircraft and vehicles on or near the airport’s runways and taxiways. It is intended to identify possible movement conflicts as they emerge and to alert  controllers by issuing audio and visual signals.

The International Federation of Air Line Pilots' Associations (IFALPA) says RIMCAS can monitor the conformance of procedures and clearances (e.g. correct taxi route or approach to parallel runways), detect conflicts on runways or taxiways (e.g. simultaneous clearances for the same runway) and unauthorized crossings of stop bars or holding points.

RIMCAS is a subsystem within the Advanced Surface Movement Guidance & Control System (A-SMGCS)