I have this absolutely revolutionary concept for airspace design...
Wait for it...
Controlled airspace, and uncontrolled airspace.
Yep. That's it. If you want to come into controlled airspace, no problems, but you need to file a flight plan, and you are subject to a clearance, and separation. No avcharges for VFR, but if controller workload is too high, clearance not available.
No more of this dodgy class 'E' where my RPT DH8-400, with 70 odd people on board, cruising along at 240kts IAS (but grounding 350kts-ish), supposedly subject to a clearance and separation, but also subject to 'see and avoid' with unknown VFR traffic. None of those dodgy class 'E' procedures (IFR pickup etc). Or at least class D as a compromise, where VFR traffic mixing it with aircraft subject to a separation service is
known VFR traffic...
Standing by for incoming....