The Berkeley County Sheriff's Department alleges a drug test showed Strobridge had cocaine in his body the day of the crash.
Each count carries a prison sentence of one to 10 years and a fine of $1,000 to $3,000.
On July 10, Strobridge was driving a dump truck on W.Va. 9 when it collided with other vehicles near and on the bridge over the Opequon Creek.
Marion Rao, 51, of Martinsburg; Carleton Wilcox, 20, of Charles Town, W.Va.; and Terry Lee Walker Jr., 17, of Leetown, W.Va., were killed in the crash.
Police said Strobridge, who was not seriously hurt, caused the crash by driving in the wrong lane.
Strobridge was charged Wednesday. He was released on bond on Thursday.
His bond was originally $300,000 - $100,000 for each count - but it was reduced to $200,000 Thursday before he was released.
Games-Neely said Strobridge is not allowed to operate a motor vehicle. Also, he must report weekly to a probation officer and must not break any laws.
If he violates those conditions, the two properties put up as collateral for a bond - a lot in the Fairfield subdivision north of Martinsburg and a 5-acre parcel in the Mill Creek District - will be seized and he will be sent to jail, Games-Neely said.
Strobridge waived the right to have a preliminary hearing within 20 days. A date for a hearing had not been scheduled by Friday afternoon.