Systems and methods for alerting a flight crew if a taxiing collision condition exists. An exemplary system on a host vehicle determines one or more first protection zones around other vehicles on the ground based on the received information about the other vehicles, determines a second protection zone around the host vehicle based on the stored information about the host vehicle and the sensor information and generates an alert, if any of the first protection zones occupies at least a portion of the same geographic area as the second protection zone. The received information includes position, ground speed, vehicle type information and heading or track information. The protection zones include a width dimension that is based on vehicle size information, a base length dimension that is based on the size information, and a variable component of the length dimension that is based on the ground speed.