The Christchurch woman suffered a fractured eye socket, a bleeding lip, other lacerations and a concussion that is still affecting her more than week after the incident.
"Today's actually my birthday and I've got a GP appointment later on this afternoon."
The 29-year-old does not know what provoked the woman.
Afterwards, the woman jumped into her own vehicle before gunning it down the road.
Smart, feeling dizzy after the assault, managed to pull her car away from the intersection and parked on the kerb before calling 111.
She said police, who are still investigating, arrived shortly afterwards before paramedics ruled her injuries were so severe she needed to be taken to the hospital to undergo a CT scan.
Just over a week after the incident, Smart - a customer services manager for a social housing trust - is unable to work until further notice.
She is due to undergo more tests at a local concussion clinic as she is still feeling the after-effects of the attack.
"I'm facing about four to six weeks of rehabilitation as I've got symptoms still.
"My short-term memory's gone, speech, I have pins and needles down one side of my body, anxiety and the paranoia is the biggest thing.
"I don't like being in public because I think: 'S***. What if she recognises me'?"