It is a road sign, Often placed where people are driving on a small road the lead to a bigger road with lots of traffic. The sign does not give traffic on the bigger road 'right of way', but the newcomer should take extra care and avoid conflics. So it means "stop your car", it could mean "stop texting" too, but the very existence of other cars than yours mean that.
https://www.edgarsnyder.com/car-accident/cause-of-accident/cell-phone/cell-phone-statistics.html
This post was edited by JakobA the unAmerican. at May 9, 2018 5:02 PM MDT