Many of those who have made donations have also paid tribute to Hu.
Dr Lam was one of the first people on the scene after Hu, also known as Alan, was killed as he was sitting behind two other cars on January 28.
Hu was wearing his seatbelt but the "strong impact" collision from the vehicle behind him appeared to kill him, Lam said.
"Alan leaves behind his devoted wife and two young daughters aged 8 and 11," the page states.
"They went from a perfectly happy, healthy family to utter devastation in the blink of an eye.
"Their lives have been torn apart and it's hard to imagine how long and arduous the journey to recovery will be."
Lam arrived on the scene soon after 5pm last Monday and worked with emergency services and a trainee nurse to try to save Hu's life.
"I have seen some things like that, but never that bad. The car that hit him must have been going very fast," he told the Herald last week.
"It is such a tragedy. This man was out enjoying the day, doing nothing wrong, waiting at the lights and then this happened, just gone, it could be any one of us."
Inspector Cornell Kluessein said three cars - an SUV, a four-wheel drive and a wagon - were waiting at the lights on Botany Rd when the third car was rear-ended.
"The last car came up at high speed and ran into the back of the third car and shunted all three of them forward," Kluessein said.
"The person in the third car died, a single occupant and the person in the last car - that hit them - was trapped initially, and had to be removed by the fire brigade."
The person in the fourth car, a Holden sedan, was removed from the car and taken to Middlemore Hospital.
The funds donated on Givealittle will be used for Hu's funeral and to support his two young daughters as their educational fund.
"On top of sorrow of losing her husband and their dad, they are now in financial hardship from the loss of his income," it reads.
"Let's band together. We can't bring back Alan but we can help relieve some of the current and future financial burden for this family."
