You have observed, over a number of weeks, that the new forklift driver is not following the safety lines. They don’t watch out and don’t bother waiting for other activities in the warehouse before they start pulling out items. There have been a couple of close calls, for example where someone was on the phone and didn’t hear the forklift, and it came pretty close to them before they realised because the driver wasn’t within the safety areas.
If you report the issues to your supervisor directly, this is following the occupational health and safety rules and should be welcomed. However, the forklift driver is likely to lose his job and you may not want to be responsible for that. If he does keep his job, he could quite easily take it out on you for reporting him.
You can choose to report this issue confidentially or to a trusted supervisor, explaining you don’t want the forklift driver to know you “dobbed’ on him.
By not reporting the issue, the risk is that a severe accident eventually happens to you or a workmate. You have to live with knowing you might have been able to prevent this.