What does it mean when the green drive 'D' light on the dash panel flashes while the CRV 2002 sport is in motion?

The green 'D' light on the dash panel might flash on a CRV 2002 Sport when it is in motion, because it is telling the driver that the transmission needs to shift to a higher gear. If the vehicle is equipped with Overdrive, this gear should be used unless towing a trailer. If the vehicle has a manual transmission, it is telling the driver to shift to a higher gear.