Commercial traffic at a key South Texas border crossing has stopped after Mexican truckers Monday blocked north and southbound lanes from Mexico. They are protesting Texas Gov. Greg Abbott’s decision to have state troopers inspect northbound commercial vehicles, historically a job done by the federal government. The bridge connecting Pharr and Reynosa is the busiest trade crossing in the Rio Grande Valley. Some produce importers in Texas said they have waited days for their goods to arrive and already had buyers cancel orders.