Earlier this January, a car (a big SUV) cut across Kelderman and six of his Bora-Hansgrohe teammates on a training ride in Italy.
The Dutchman suffered concussion and a fractured vertebra in his neck, while Andreas Schillinger broke several vertebrae and Rudiger Sulig was also concussed.
Despite these injuries, Kelderman is thankful the incident didn't turn out worse.
"I can actually remember everything. It was really s***," he told Cyclingnews.
"In one moment, a big Mercedes SUV came across. They didn’t stop at all and just drove into our group.
"I saw it coming but I couldn’t even brake. It was scary and it went so fast.
"All of a sudden I was on the ground and it was a big mess. The driver just came in from the side at a junction and she just didn’t stop," he explained.
"She wanted to cross but it simply wasn’t possible and she just drove straight into us.
"I don’t think that she was arrested but she was in a lot of stress. It was her fault but I don’t know what’s next.
"The police came and wrote it all up the next day. I don’t know how it will go in the next few weeks but it was scary."
"That moment was really frustrating but the neck has been much better. If you saw the accident with the car, it could have been a lot worse. I’m happy that no one has had really big problems."
Kelderman, who finished third in last year's Giro d'Italia, is recovering faster than expected and keeping his fitness up on a home trainer.
"I just have to be careful but I can train inside and I can do a lot of Zwifting," he said.
"It will take more time to heal the fracture and for sure I don’t want to take any risks. It’s another four to six weeks until I go back into competition. We’ve not talked about programme changes yet but that will happen in the next couple of weeks.
"For sure I’ll do the Tour de France. That was already planned.
I’ve never gone in with really good shape for the Tour and it’s hard to say what will happen and how the others will go, or even who is riding the Tour.
"I’m going to try and go for the top five or top-10. Whatever is possible."