The three along with Bouchard's boss were struck after they had ridden about 15 miles, Rogers said.
Wells leaves behind her husband and two children, ages 16 and 17.
No charges have been filed against Hess. She didn't immediately respond to a message seeking comment.
The bicycling club each year pays police to man various intersections during the event and has nearly 80 volunteers helping, Wallenstein said.
"It's just a tragic event," he said.