Johnson, 41, was charged 19 weeks after the crash on Beech Island Avenue that critically injured Dr. Matthew Burke, an orthopedic surgeon at Fort Gordon. Burke died Sunday.
Johnson was booked at 7:25 p.m. Lance Cpl. Judd Jones of the South Carolina Highway Patrol confirmed the charge Tuesday night.
The crash happened about 6:40 p.m. on Oct. 1 as a group of about 15 cyclists pedaled their usual Friday route after leaving Outspokin' Bicycles in Augusta.
Some cyclists said they heard a pickup's engine revving right before the moment of impact on the rural, two-lane road. The impact knocked over four cyclists but launched Burke into the air. He suffered severe head injuries and remained in a coma until his death.
Burke, a U.S. Army major, worked at Dwight D. Eisenhower Army Medical Center and spent six months in Iraq. He is survived by his wife, Bonnie, and 11-month-old daughter, Anna.
A funeral is scheduled for 1 p.m. Saturday at St. Mary on the Hill Catholic Church, his brother, Paul Burke, said Tuesday.
Laura Farmer was one of the cyclists struck by the Dodge Durango driven by Johnson.
The road rash on her arm has healed into a scar, but a torn rotator cuff still pains her, even after more than four months of therapy.
She said she has been troubled by the pace of the investigation, but was glad to hear that a charge had been filed.
"That's good news," she said.
A message for Solicitor Strom Thurmond Jr. in Aiken was unreturned Tuesday.
South Carolina law defines "reckless homicide" as driving a vehicle with "reckless disregard of the safety of others."
A person who pleads no contest or is convicted of the charge faces no more than 10 years in prison and a mandatory five-year driver's license revocation, according to scstatehouse.gov.
In a separate incident, cyclist Pascal Limouzin is still in the hospital after he was hit by a car Jan. 23 on Banks Mill Road in Aiken.
The driver, Drew Ward, fled but turned himself in a week later and is charged with hit-and-run with great bodily injury, according to SCHP.
Tom Lex with the Aiken Bicycle Club said safety on the road is the responsibility of both motorists and cyclists.
Law enforcement can help to a point, but most roads in Aiken County belong to the state and troopers are spread too thin to be much help, Lex said.
"What is feasible is thoroughly educating the public on the laws and rights of cyclists on the road," Lex said.
Since the wreck in October, Farmer has ventured out twice on a bicycle. But it has been on a protected path away from the road at Fort Gordon.
Whether she rides in Beech Island again is another question.
"Maybe when people pay better attention," she said.