In this morning's news... concrete block are being dumped on a freeway to cause unsuspecting drivers to wreck in the middle of the night, 10pm to 2 am, on Interstate 8, East of San Diego

California Highway Patrol officers suspect someone is purposely leaving concrete blocks, parking stops and other debris on Interstate 8, triggering dangerous late night crashes in unincorporated El Cajon near Alpine on Saturday night.

Units arrived to find about 10 cars had suffered bent wheels and flat tires after they hit a concrete parking stop that had been placed in the roadway. Four concrete parking stops -- weighing about 60 pounds -- and three cinder blocks were also found nearby.

Reports of the suspicious accidents first cropped up in January and February of this year, when landscaping blocks lying on I-8 westbound, east of Dunbar Lane, caused a series of crashes on four separate occasions. Each time, the accidents occurred between 10 p.m. and 2 a.m. -- and each time, the same kind of large blocks were found in the traffic lanes.

http://fox5sandiego.com/2018/06/09/chp-someone-is-using-concrete-blocks-to-cause-crashes-on-i-8/
http://www.kusi.com/concrete-debris-left-on-i-8-causes-crashes-and-car-damage/