Cones are spaced 50 feet apart where Caltrans workers are "tapering" to shut of a lane, and 100 feet apart at the closed lane. That marks the work site and discourages people from trying to drive into the closed lane, which can result in tragic consequences. The fact that cones appear to be just a few feet apart helps illustrate that things move fast at freeway speeds -- another good reason to slow down in a work zone.