Arco Norte Robbery

When I was in the military, I lived in different countries. We were told to only carry minimal amounts of money and not flash expensive items. We carried enough money that any robbers wouldn't get too upset at what little money we had but enough to get by for the day. Probably a good rule of thumb for here in the U. S. and when we travel to Mexico

I was last on the Arco Norte in February 2020. At that time I noticed a man watching traffic from overpasses out in the less populated areas. These men had some type of flag or cloth they would appear to use to signal others - not necessarily the traffic they were monitoring. We were traveling alone on a motorcycle so I was somewhat concerned about the intent. It might have been harmless and related to trucking but still it struck me - a 20 year visitor and traveler in Mexico - as something that could be worrisome.
Most if not all of these monitored overpasses had no exit or entrance ramps. I saw this at least 6 times at different overpasses in that area.