The company contracted to undertake the modifications of the Spa-Francorchamps Formula 1 circuit have admitted they had "over 20 iterations" of Eau Rouge during the process.
Between the 2021 'race' and the 2022 event, Spa has undergone major work to widen run-offs, create new service and access roads as well as the placing of gravel traps around the circuit.
The idea is to increase safety and spectator viewing, especially at the famed Eau Rouge/Raidillon complex.
This section of track had come in for criticism from drivers in recent years following a series of high-speed accidents caused by the wall being too close at the top of the hill. It was in this area of track where Anthoine Hubert was killed in the 2019 Formula 2 Feature Race.
Coupled with track resurfacing following floods in the winter, the work is extensive as Spa fights to retain a place on the 2023 F1 calendar.
"20 iterations of Eau Rouge"
Jarno Zaffelli's Dromo Circuit Design was given the work to upgrade and renovate Spa, with the big focus point being on safety at the famed corner.
"The target was to modernise and improve the safety of Eau Rouge," he explained to media including RacingNews365.com.
"We were engaged after the floods did a lot of damage and we determined how to restore the area and improve the racing show, reducing the bumps, allowing for rain disbursement and overall [making it] safer – whilst ensuring the most iconic corner in motorsport retained its unique character.
"In the design and development, we took into consideration the new [F1] regulations and tyres. We had 20+ iterations of 'Eau Rouge'.
"We spent several days with professional drivers in our in-house simulators to get their feedback, and then two full days in the Vi-grade sim centre with Thierry Boutsen and Emanuele Pirro.
"This work helped us to choose the final design that was submitted to the FIA Circuit Commission."
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Resurfacing for first time in 20 years
Sections of the track have been resurfaced, including Eau Rouge and the climb up the hill, with Zaffelli saying this was a necessity.
"The last time the track was paved was almost 20 years ago, and the performance of race vehicles and motorbikes have hugely increased," he explained.
"The technology available for the asphalt materials and paving equipment have changed dramatically.
"The key challenge was the 31m track slope from the bottom of Eau Rouge to the top. It is a technical challenge, complicated by the time of year we had to pave in with the low temperatures.
"During the World Endurance Championship six hours race, we got very positive feedback from teams, race engineers, tyre companies and drivers.
"The cars will feel the difference between the new asphalt and the old one, but we know that this year F1 cars are generally slower than 2021, so there won't be too big a gap."
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