They have clipboards like they are tracking cars Is Big Brother watching? I see them during the morning and afternoon commute, with orange vests on, in cars or standing on the Lakeview bridge, observing the traffic.
The most likely culprit is the relay for the turn signal switchYou'll probably have to go to a GM dealer to get the part, but if you ask the folks in the parts department very nicely they'll probably tell you where the switch is located in your car and how to change it out.
Needs a new flasher ! Go to Auto-Zone !
Check to make sure all the bulbs are good all the way aroundYou may want to check the flasher or flasher relayDo the emergency flashers work? You can switch around the flashers and see if that fixes it, that would be a good way to test itIf it's got a flasher relay, it will not function for either turn signal or emergency flasherThen replace the flasher.
They are counting the number of vehicles with high occupancy (two occupants or more)This type of traffic count cannot be done by machines cheaply and with acceptable precision.