"I'm really just in utter disbelief," Eff said. "I don't know how somebody could do something like that and not have the kindness to assist me."
It happened the weekend before Christmas. Eff left a friend's house early in the morning and was crossing Michigan Avenue at Pearson.
"I remember trying to get a cab and that's all I remember," she said. "Fortunately."
Fortunately because when she was hit, both her legs were broken, her elbow shattered, her shoulder fractured and she was left with two fractured vertebrae in her neck.
Eff woke up in the hospital a week later, on Christmas Day.
The 28-year-old, who ran the Chicago marathon in 2010, now walks slowly today, thanks to metal rods in her legs and rehab therapy. She can barely move her left arm.
"I would like if the person could at least come forward and say they were involved in this," she said.
Eff is grateful for another person, a Good Samaritan.
Jenny Hsieh was in a cab that night and saw Eff lying in the street. A respiratory therapist, Shieh's training kicked in.
"Of course, being a healthcare provider my first reaction was to make sure she was OK," Hsieh said.
Eff's family has already thanked Hsieh, who they believe to be a lifesaver, but Eff has not yet had the opportunity.
"I would like to meet her," Eff said. "I mean, it goes without words how grateful I am for her assistance. And it really takes a strong person to get out and help someone in that way, and I'm forever grateful to her."