Roll hoops came under the spotlight after Alfa driver Zhou Guanyu's huge accident at the start of last year's British GP.
Alfa was the only team using the blade design permitted by the FIA, and in an unprecedented occurrence, its pointed top dug into the track and was eventually snapped off.
The incident prompted an investigation by the FIA, which included three meetings of the Technical Advisory Committee in which all teams play a role.
One of the conclusions reported by the FIA was that "the wording, as currently in the regulations, allows teams to homologate their roll hoops with forces acting through a lower point than intended. This can lead to the roll hoop resisting forces that are lower than originally intended by the regulations".
For 2023 the FIA duly mandated "a change to require a rounded top of the roll hoop, which will reduce the chance of it digging into the ground during an accident," plus "a change to ensure a minimum height for the point of application of the homologation test" and "the creation of a new physical homologation test where the load pushes the roll hoop in the forward direction."
In addition, the FIA confirmed that it will introduce much stricter load tests for 2024, while giving teams enough time to comply with the new requirements.
Alfa had already decided that it was too late to abandon the blade for this season.
However, in addition to complying with the 2023 requirements, including a more curved top, the team has also decided to meet the load tests planned for 2024 as an extra safety measure.
"We will use a completely different roll hoop," Alfa technical director Jan Monchaux told Motorsport.com.
"It's still a blade, because when the decision was made to change or tweak the rules, it was at a point where we had already made some strategical decisions on what is carry over and what is not, from which we couldn't revert, because it was summer.
"And all the other teams were in a similar situation. So we agreed between FIA and the teams to do effectively three steps.
"A first step is in '23, which is mainly a geometrical constraint to avoid sharp edges that cut and things like this on the top, to make it harder for a roll hoop in such a situation to dig into the track.
"For '24 there are some additional rules and some new load cases that are more demanding, that everyone will have to pass.
"What we decided to do was to already anticipate our roll hoop shape, investing extra weight, to fit the 2024 rules. Because we were involved in the accident, we didn't just want to comply with the '23 demands, we made a further step already, strictly speaking being legal for '24."
Monchaux acknowledged that the FIA would have made the stricter tests compulsory for all teams in '23 had the Zhou incident and subsequent investigation not happened so late in the season.
"Even if we are probably going to have a different roll hoop in '24, we made an extra effort, because we had to and we felt obliged to do that for our drivers.
"And also, because the FIA could have changed more for '23, but it was kind of too late. At some point, you need to be also realistic, you can't force teams in August to re-do a chassis for the following season. It's too late.
"So it will still be a blade, but it's a significant departure from what we had. It's smoother, fatter, stronger. The original roll hoop did its job, because people tend to forget that it did its job, Zhou had no bruises. And now it would do an even better job, let's put it like this.
"We are working very hard also with the FIA in view of '26 to improve in general the roll hoop specification, because there is room for improvement for F1 for the topic of roll hoops, not just us. We can do a better job on this subject for '26 for the new rules."
