Josh Powell is in a critical condition in hospital with his 18-month-old child after his family’s people carrier and a heavy goods vehicle collided.
Wife Zoe Powell, 29, and daughters Amelia, four, and Phoebe, eight, and six-year-old son Simeon died in the incident on Monday evening.
The HGV driver, a 56-year-old man, suffered minor injuries.
The JustGiving crowdfunder, set up by Andrew Welsford, states: “This (is) such a sad and tragic loss for a work colleague on the railway, whose family have been taken from him in a tragic car crash near Oxford.
“Many people in the world of the Orange Army (rail workers, who use high-vis jackets) will know Josh and I hope will contribute to give him some financial support when he needs (it) later in recovery.”
Welsford said Josh Powell is a contractor in the railway industry.
The crowdfunder raised £59,713 by Thursday morning, well past the initial goal of £1,000, with more than 1,600 people donating.
Watch: Community reacts to tragic Oxford car crash
Tributes left to the family were made by people in Chinnor, Oxfordshire, where they lived.
It emerged on Wednesday that the family had recently endured a house fire and were moving around before finding a long-term place.
A neighbour who did not want to be named said “there was smoke pouring from their house”.
“It’s incredibly sad, it was a hard enough year for them regardless, and now this… it’s just incredible.
“It’s rather raw and it’s horrendous. They were all absolutely lovely – the children were a delight, they were bouncy, bubbly, just really happy children.”
Reverend Dr Jacky Barr, of St Andrew’s Church in Chinnor, where the family attended, said: “They were just a delightful family. The children were always very engaging.
“They were just a lovely family, they really were. This has come as such a shock and loss to us all in the area.”
Sergeant Dominic Mahon, of Thames Valley Police, said the crash scene was “incredibly upsetting” and urged anyone who saw what happened to contact police.
Watch: What is the Bounce Back scheme?