dedja wrote:I’d like to see how the faark you make a track enclosed by 4 tonne concrete barriers with no run off safe for motorbikes.

Chat GPT tended to agree with you. However after analyzing the FIM safety regulations it came up with this......
Proposed layout: Pakapakanthi GP Circuit (Adelaide)
Length: ~4.7–5.0 km target, anti‑clockwise.
Location: 80–90% inside Victoria Park / Pakapakanthi, with carefully selected use of Wakefield Rd (east end) and Dequetteville Tce (northbound) only where wide medians/park edges allow deep run‑off pockets to be built. [fim-moto.com]
Rationale: Keeps spectators near the city while ensuring that primary impact directions face open parkland—so we can build the verges, asphalt run‑off, gravel beds, and secondary energy‑absorbing barriers demanded by FIM circuit design before any crowd fencing. [fim-moto.com]
Note on numbers: Exact run‑off depths and barrier types are determined by the FIM homologation process using corner speeds/angles and simulations; the concept below spells out where and how to create those spaces so the design can achieve Grade A once engineered. [fim-moto.com]
Start / Finish + T1 (fast left, in‑park)
Design: Gentle kink leading to a 90–110° left.
Safety: Build a deep asphalt extension plus gravel bed on the outside (rider’s right) with the first protection line set far back in parkland, then air barriers before any perimeter fence. Spectators placed behind the second protection line. [fim-moto.com]
T2/T3 (left–right infield complex)
Design: Medium‑speed “S” which naturally lowers exit speed.
Safety: Wide verges both sides; plant the first line of protection only after continuous clear run‑off; use soft barriers where escape vectors converge. [fim-moto.com]
Back‑straight (in‑park) → T4 Hairpin (anchor braking zone)
Design: Long acceleration zone culminating in a tight left hairpin located deep inside the park to avoid roadside obstructions.
Safety: Triangular run‑off pocket extending far past the hairpin apex, with an ample gravel bed and air modules aligned to expected impact angles. Service road access behind the second line for recovery. [fim-moto.com]
Link to Wakefield Rd (short public section) → T5 left
Design: Rejoins a short, widened (temporary lane shift) section of Wakefield Rd.
Safety: On outside of T5, remove/relocate street furniture and prune/set back trees to create a broad clear zone; build temporary asphalt run‑off tapering to gravel; position protection lines well inside the park perimeter, not on the kerb. [fim-moto.com]
Dequetteville Terrace northbound sweep → T6 chicane
Design: A speed‑conditioning left–right chicane before the bend that parallels Rymill/Kurrangga Park to keep velocities within run‑off capacity.
Safety: Outside of the initial left has longitudinal asphalt then gravel; secondary protection with soft barriers placed behind the gravel; spectators only behind the second protection line. [fim-moto.com]
Re‑enter Park (T7/T8 medium lefts)
Design: Two flowing lefts back into open space.
Safety: The outside is open grassed parkland—grade it smooth, remove isolated obstacles, and push barriers far back; use additional protective devices only where geometry concentrates risk. [fim-moto.com]
Infield fast ‘esses’ → T9 braking left (another anchor)
Design: Rising speed through ‘esses’ into a strong braking left placed with run‑off pointing into empty infield.
Safety: Large paved run‑off for initial deceleration transitioning to gravel, with air modules at the back of the pocket. Marshal points and medical access per FIM posts & intervention guidance. [fim-moto.com]
Short chute → T10/T11 technical left–right → pit entry
Design: Slows the lap before the pit entry.
Safety: Symmetrical verges and clear zones both sides; any structures (bridges, light gantries) must respect FIM track‑side structure clearances and be outside the first protection line. [fim-moto.com]
Pits, paddock, medical, and operations
Pits & paddock: Use the Victoria Park infield for pit lane, garages (temporary but rigid), and paddock hard‑stand, sized and arranged per FIM pit‑lane, signalling and scrutineering provisions. [fim-moto.com]
Marshal posts & signalling: Site posts with clear sightlines and safe access behind protection lines; deploy FIM‑compliant light panels/flag posts and a full CCTV race control. [fim-moto.com]
Medical/Rescue: On‑site medical centre with helicopter access, multiple intervention roads behind the second protection line, and rapid extraction points planned at both anchor braking zones. [fim-moto.com]