Zippers are what professional truck drivers call vehicles which race ahead of others at a lane merge, then cut into the line dangerously.
This year Tennessee, Arkansas and Washington are issuing tickets to drivers who do not merge properly in a work zone. The effort is welcomed by the trucking industry.
Tennessee, for example, now expects drivers to begin merging when they first see posted signs and completely merge within two miles as they encounter do-not-pass signs. Failure to merge safely can warrant a ticket.